DAY-AHEAD SCHEDULING METHOD AND APPARATUS FOR POWER SYSTEM, ELECTRONIC DEVICE AND STORAGE MEDIUM
20250105632 ยท 2025-03-27
Assignee
Inventors
Cpc classification
H02J2310/00
ELECTRICITY
H02J3/466
ELECTRICITY
H02J3/004
ELECTRICITY
International classification
H02J3/46
ELECTRICITY
H02J3/00
ELECTRICITY
Abstract
The present application provides a day-ahead scheduling method and apparatus for a power system, an electronic device, and a storage medium, where the method includes: obtaining power system prediction parameters in a to-be-scheduled time period, where the power system prediction parameters include thermal power unit parameters, renewable energy station parameters, load parameters, energy storage station (ESS) parameters, node parameters, a transmission line parameter and other power gird parameters; constructing a day-ahead scheduling optimization model and generating multiple renewable energy power scenarios based on the power system prediction parameters; solving the day-ahead scheduling optimization model to obtain day-ahead scheduling results; verifying the day-ahead scheduling results based on the power system prediction parameters and the multiple renewable energy power scenarios; and in case that the verifying the day-ahead scheduling results successes, outputting the day-ahead scheduling results. In the method, the impact of the renewable energy station grid-connected proportion instructions on the renewable energy power scenarios is characterized by generating multiple renewable energy power scenarios, the voltage security for nodes in the power system is ensured by constructing the day-ahead scheduling optimization model, the feasibility of intraday power grid operation is ensured by verifying the day-ahead scheduling result, and the power system is safely and economically scheduled under the condition of voltage security.
Claims
1. A day-ahead scheduling method for a power system, comprising: obtaining power system prediction parameters in a to-be-scheduled time period, wherein the power system prediction parameters comprise thermal power unit parameters, renewable energy station parameters, load parameters, energy storage station (ESS) parameters, node parameters, a transmission line parameter and other power gird parameters; constructing a day-ahead scheduling optimization model and generating multiple renewable energy power scenarios based on the power system prediction parameters; solving the day-ahead scheduling optimization model to obtain day-ahead scheduling results; verifying the day-ahead scheduling results based on the power system prediction parameters and the multiple renewable energy power scenarios; and in case that verifying the day-ahead scheduling results successes, outputting the day-ahead scheduling results.
2. The method of claim 1, wherein constructing the day-ahead scheduling optimization model based on the power system prediction parameters comprises: constructing an objective function for power system day-ahead scheduling optimization problem and objective constraints corresponding to the objective function based on the power system prediction parameters.
3. The method of claim 2, wherein the objective function for power system day-ahead scheduling optimization problem is as follows: is a set of scheduling time periods,
.sub.G is a set of thermal power units, c.sub.i.sup.g is a cost per unit power output, p.sub.i.sup.g(t) is active pre-output power of a thermal power unit i in a time period t, c.sub.i.sup.spare is a regulation spare cost for regulating up and down per unit, r.sub.i.sup.g,up(t) is an uphill capacity of the thermal power unit i in the time period t, r.sub.i.sup.g,dn(t) is a downhill capacity of the thermal power unit i in the time period t, w.sub.j.sup.pption(t) is a renewable energy station grid-connected proportion of a renewable energy station j in the time period t, p.sub.d.sup.dr(t) is a protocol capacity of a demand side response of a load d in the time period t, p.sub.j,y.sup.re,cut(t) is a renewable energy power reduction value of the renewable energy station j in the time period t, p.sub.j,y.sup.re(t) is a renewable energy power grid-connected value of the renewable energy station j in the time period t, p.sub.d,y.sup.load(t) is a load power supply value of the load d in the time period t, p.sub.d,y.sup.load,cut(t) is a demand side response usage value of the load d in the time period t, p.sub.i,y.sup.gc(t) is unit real-time active power output of the thermal power unit i in the time period t, q.sub.i,y.sup.gc(t) is unit real-time reactive power output of the thermal power unit i in the time period t, p.sub.k,y.sup.e,ch(t) is active charging power of an energy storage station k in a scenario y and the time period t, p.sub.k,y.sup.e,dc(t) is active discharging power of the energy storage station k in the scenario y and the time period t, E.sub.k,y(t) is stored energy of the energy storage station k in the scenario y and the time period t, q.sub.k,y.sup.e(t) is reactive power injected by the energy storage station to the power grid, p.sub.l,y.sup.brch(t) is active power flow of a transmission line l in the scenario y and the time period t, q.sub.l,y.sup.brch(t) is reactive power flow of the transmission line l in the scenario y and the time period t, s.sub.y.sup.1(t)s.sub.y.sup.2(t) are slack variables of active power balance in the power system, s.sub.y.sup.3(t)s.sub.y.sup.4(t) are slack variables of reactive power balance in the power system, s.sub.y.sup.5(t)s.sub.y.sup.12(t) are line capacity slack variables considering active power flow and reactive power flow, v.sub.b,y.sup.amp(t) is a node voltage of a node b in the scenario y and the time period t, p.sub.b,y.sup.bus(t) is an active power input value of the node b in the scenario y and the time period t, q.sub.b,y.sup.bus(t) is a reactive power input value of the node b in the scenario y and the time period t, .sub.b,y(t) is a node phase angle value of the node b in the scenario y and the time period t, r.sub.i,y.sup.gc,use(t) is an auxiliary variable for obtaining the active power spare usage amount, q.sub.i,y.sup.gc,use(t) is an auxiliary variable for obtaining the reactive power spare usage amount, q.sub.k,y.sup.e,use(t) is an auxiliary variable for obtaining the reactive power spare usage amount of the energy storage station,
.sub.R is a set of the renewable energy stations, c.sub.j.sup.pption is a unit cost of the renewable energy station grid-connected proportion regulation instruction,
.sub.D is a set of the loads, c.sub.d.sup.dr is a cost of the demand side response per unit capacity,
.sub.Y.sup.n is a set of typical renewable energy scenarios, .sub.y is a variable of power system operating cost in the scenario y, d is an index of the loads, i is a thermal power unit number, j is an index of the renewable energy stations, k is an index of the energy storage stations, t is a scheduling time point, y is an index of the renewable energy scenarios, l is an index of the transmission lines, and |
.sub.Y.sup.n| is a number of elements comprised in the set of typical renewable energy scenarios
.sub.Y.sup.n.
4. The method of claim 3, wherein the objective constraints comprise voltage security constraints, and the voltage security constraints comprise: a constraint of node voltage amplitude: is a set of the nodes; a constraint of node active power:
.sub.T.sup.NOW is a set of scheduling time periods; a constraint of a relationship among node reactive power, the node voltage amplitude and the node voltage phase angle:
5. The method of claim 1, wherein the step of generating multiple renewable energy power scenarios comprises: for a renewable energy station j in a scheduling time period t, generating a random number R.sub.rand.sup.j,t in an interval [0,1] that obeys uniform distribution, then there must be an integer M.sub.0 (1M.sub.0M.sub.GMM) so that the following formula is workable:
6. The method of any of claims 1 to 5, verifying the day-ahead scheduling results based on the power system prediction parameters and the multiple renewable energy power scenarios comprises: for each renewable energy power scenario, constructing an intraday scheduling optimization model based on the day-ahead scheduling results and the power system prediction parameters; solving the intraday scheduling optimization model to obtain a multi-stage optimal solution of variables in the renewable energy power scenario; calculating a penalty cost corresponding to the day-ahead scheduling results based on the multi-stage optimal solution of the variables; and verifying the day-ahead scheduling results based on the penalty cost.
7. The method of claim 6 further comprises: in case that the verifying the day-ahead scheduling results fails, updating a cutting plane set based on the penalty cost corresponding to the day-ahead scheduling results; optimizing the day-ahead scheduling results based on an updated cutting plane set, and verifying an optimized day-ahead scheduling results; and in case that the verifying the optimized day-ahead scheduling results successes, outputting an optimized day-ahead scheduling results.
8. A day-ahead scheduling apparatus for a power system, comprising: a power system prediction parameter obtaining module, used for obtaining power system prediction parameters in a to-be-scheduled time period, wherein the power system prediction parameters comprise thermal power unit parameters, renewable energy station parameters, load parameters, energy storage station (ESS) parameters, node parameters, a transmission line parameter and other power gird parameters; a renewable energy power scenario generating module, used for constructing a day-ahead scheduling optimization model and generating multiple renewable energy power scenarios based on the power system prediction parameters; a day-ahead scheduling optimization model solving module, used for solving the day-ahead scheduling optimization model to obtain day-ahead scheduling results; day-ahead scheduling results verifying module, used for verifying the day-ahead scheduling results based on the power system prediction parameters and the multiple renewable energy power scenarios; and day-ahead scheduling results outputting module, used for, in case that the verifying the day-ahead scheduling results successes, outputting the day-ahead scheduling results.
9. An electronic device, comprising a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the computer program, when executed by the processor, causes the electronic device to perform the method of any of claims 1 to 7.
10. A non-transitory computer readable storage medium storing a computer program that, when executed by a processor, causes the processor to perform the method of any of claims 1 to 7.
Description
BRIEF DESCRIPTION OF DRAWINGS
[0047] In order to illustrate the solutions of the embodiments more clearly according to the present application and the related art, the accompanying drawings used in the description for the embodiments or the related art are briefly introduced below. It should be noted that the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings may be obtained according to these drawings without creative effort.
[0048]
[0049]
[0050]
[0051]
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0052] The solutions according to the present application are clearly described below in combination with the accompanying drawings in the embodiments of the present application. It should be noted that the described embodiments are some embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.
[0053] In order to solve the problem that the decision-dependent uncertainty for renewable energy and the voltage security of power system are not fully considered in traditional power system scheduling modes, the present application provides a day-ahead scheduling method for a power system in which the decision-dependent uncertainty for renewable energy and the voltage security of power system are considered.
[0054] As shown in
[0056] It should be noted that, when the power system day-ahead scheduling is performed, a data preparation operation needs to be performed first. In an embodiment, the power system prediction parameters in a to-be-scheduled time period are obtained, where the power system prediction parameters include thermal power unit parameters, renewable energy station parameters, load parameters, energy storage station (ESS) parameters, node parameters, a transmission line parameter and other power gird parameters.
[0057] The to-be-scheduled time period may be set based on an actual situation. For example, the to-be-scheduled time period is a next day, and the step S110 is to obtain the power system prediction parameters within the next day.
1) Thermal Power Unit Parameters.
[0058] An index of the thermal power unit is denoted as i, parameters of the thermal power unit include an active power output range [P.sub.i.sup.gen,
[0059] A set of the thermal power units i is denoted as .sub.G, and the number of the thermal power units is denoted as N.sub.G.
2) Renewable Energy Station Parameters.
[0060] An index of the renewable energy station is denoted as j, parameters of the renewable energy station include a grid-connected proportion regulation range [W.sub.j.sup.pption,
[0061] It should be noted that, in the present application, in case that Gaussian mixture model (GMM) is used to represent the probability distribution of the renewable energy output, an active GMM parameter set of the renewable energy station j in the time period t is:
.sub.j,t.sup.R={.sub.j,t,m.sup.R,P.sub.j,t,m.sup.R,,P.sub.j,t,m.sup.R,,m=1, . . . ,M.sub.GMM}, [0062] where M.sub.GMM is the number of Gaussian components, .sub.j,t,m.sup.R is a weight coefficient of an m-th Gaussian component (0<.sub.j,t,m.sup.R<1 and .sub.m=1, . . . , M.sub.
[0063] A set of the renewable energy stations j is denoted as .sub.R, and the number of the renewable energy stations j is denoted as N.sub.R.
3) Load Parameters.
[0064] An index of the load is denoted as d, parameters of the load include an active power demand P.sub.d,t.sup.D and a reactive power demand Q.sub.d,t.sup.D of the load d in the time period t, a generation shift factor SF.sub.l,d of the load d with respect to the transmission line l, a position correlation matrix BF.sub.b,d.sup.D of the load d with respect to the node b, a protocol capacity upper limit
[0065] A set of the loads is denoted as .sub.D, and the number of the loads is denoted as N.sub.D.
4) ESS Parameters.
[0066] An index of the energy storage station is denoted as k, the parameters of the energy storage station include an upper limit of active charging and discharging power
[0067] A set of the energy storage is denoted as .sub.ESS, and the number of the energy storage is denoted as N.sub.ESS.
5) Node Parameters.
[0068] An index of the node is denoted as b, parameters of the node include a voltage amplitude allowable variation range [V.sub.b.sup.amp,
[0069] A set of the nodes is denoted as , and the number of the nodes is denoted as N.sub.B.
[0070] In addition, the parameters of the node further include a node admittance matrix Y.sup.NET of the power grid, a node admittance matrix Y.sub.NET* without considering bypass capacitance, a real part G.sub.b1,b2.sup.NET of an element corresponding to a row b1 and a column b2 in the node admittance matrix Y.sup.NET, an imaginary part B.sub.b1,b2.sup.NET of the element corresponding to the row b1 NET of an and the column b2 in the node admittance matrix Y.sup.NET, and an imaginary part B.sub.b1,b2.sup.NET* of an element corresponding to a row b1 and a column b2 in the node admittance matrix Y.sup.NET*.
6) Transmission Line Parameter.
[0071] An index of the transmission line is denoted as, a parameter of the transmission line includes a maximum power transmission capacity
[0072] A set of the transmission line is denoted as , and the number of the transmission line is denoted as N.sub.L.
[0073] It should be note that, in case that two nodes corresponding to the transmission line l are b1 and b2, a conductance and a susceptance of the transmission I may be denoted as g.sub.b1,b2.sup.NET and u.sub.b1,b2.sup.NET respectively.
7) Other Power Grid Parameters.
[0074] The other power grid parameters include a unit scheduling cost c.sup.S of active power balance emergency regulation resources and transmission line congestion emergency regulation resources, and a unit scheduling cost c.sup.SL of reactive power balance emergency regulation resources and the transmission line congestion emergency regulation resources. [0075] S120: constructing a day-ahead scheduling optimization model and generating multiple renewable energy power scenarios based on the power system prediction parameters. [0076] S130: solving the day-ahead scheduling optimization model to obtain day-ahead scheduling results.
[0077] It should be noted that, on the basis of obtaining the power system prediction parameters in the to-be-scheduled time period in step S110, further, in step S120, the day-ahead scheduling optimization model is constructed based on the obtained power system prediction parameters, and multiple renewable energy power scenarios are generated based on the obtained power system prediction parameters, and in step S130, the day-ahead scheduling optimization model is solved to obtain the day-ahead scheduling result.
[0078] It should be noted that, in this embodiment, the process of the power system day-ahead scheduling involves a three-layer structure, including an upper level, a middle level and a lower level.
[0079] In the upper level, the day-ahead scheduling optimization model is constructed based on the power system prediction parameters, the constructed day-ahead scheduling optimization model is solved to obtain the day-ahead scheduling results.
[0080] In the middle level, multiple renewable energy power scenarios are generated based on the power system prediction parameters.
[0081] In the lower level, the day-ahead scheduling results transmitted from the upper level and the multiple renewable energy power scenarios transmitted from the middle level are received, and the day-ahead scheduling results are verified based on the power system prediction parameters and the multiple renewable power scenarios.
[0082] In step S120, the day-ahead scheduling optimization model is constructed base on the power system prediction parameters, where the day-ahead scheduling optimization model includes an objective function for power system day-ahead scheduling optimization problem and objective constraints corresponding to the objective function.
[0083] Accordingly, constructing the day-ahead scheduling optimization model includes constructing the objective function for power system day-ahead scheduling optimization problem and the objective constraints corresponding to the objective function, and there are multiple objective constraints (elaborated in the below embodiments).
[0084] Further, in step S130, multiple renewable energy power scenarios may be generated based on the power system prediction parameters. In an embodiment, since an active power GMM parameter set .sub.j,t.sup.R of the renewable energy station j (j=1, . . . , N.sub.R) is: .sub.j,t.sup.R={.sub.j,t,m.sup.R,P.sub.j,t,m.sup.R,,P.sub.j,t,m.sup.R,,m=1, . . . , M}, denoting
the multiple renewable energy power scenarios h in a renewable energy power scenario set .sub.RO.sup.n may be generated by the following mode: [0085] for the renewable energy station j in the time period t, a random number R.sub.rand.sup.j,t is generated in an interval [0,1] that obeys uniform distribution, then there must be an integer M.sub.0 (1M.sub.0M.sub.GMM) so that the following formula is workable:
[0087] The renewable energy output probability distribution is represented by a GMM, M.sub.GMM is the number of Gaussian components in the renewable energy output probability distribution, and .sub.j,t,m is a weight coefficient of an m-th Gaussian component in the renewable energy output probability distribution.
[0088] Further, the renewable energy power scenario p.sub.j,t.sup.renew,h (t, j
.sub.R, h=1, . . . , N.sub.RO) of the scenario h in the renewable energy power scenario set N.sub.RO may be obtained by traversing both the time period t and the renewable energy station j. The N.sub.RO renewable energy scenarios P.sub.j,t.sup.renew,h (multiple renewable energy power scenarios) constitute the renewable energy power scenario set
.sub.RO.sup.n.
[0089] h is an index of each of the renewable energy scenarios in the renewable energy power scenario set .sub.RO.sup.n.
[0090] On the basis of constructing the day-ahead scheduling optimization model in step S120, in step S130, the day-ahead scheduling optimization model is solved to obtain the day-ahead scheduling results.
[0091] The day-ahead scheduling results include a pre-output value {tilde over (P)}.sub.i.sup.g,n(t) of the thermal power unit, an uphill spare tuning value {tilde over (R)}.sub.i.sup.g,up,n(t) of the thermal power unit, a downhill spare tuning value {tilde over (R)}.sub.i.sup.g,dn,n(t) of the thermal power unit, a renewable energy station grid-connected proportion instruction {tilde over (W)}.sub.j.sup.pption,n(t), and a protocol capacity {tilde over (P)}.sub.d.sup.dr,n(t) of a demand side response.
[0092] It should be noted that, there is no strict logical sequence between the step of constructing the day-ahead scheduling optimization model in step S120 and the step of generating multiple renewable energy power scenarios, and neither there is a strict logical sequence between the step of generating multiple renewable energy power scenarios in step S130 and S120. [0093] S140: verifying the day-ahead scheduling results based on the power system prediction parameters and the multiple renewable energy power scenarios. [0094] S150: in case that verifying the day-ahead scheduling results successes, outputting the day-ahead scheduling results.
[0095] It should be noted that, in step S140, the lower level verifies, based on the power system prediction parameters in the to-be-scheduled time period obtained in step S110 and the multiple renewable energy power scenarios generated in step S120, the day-ahead scheduling results obtained by solving the day-ahead scheduling optimization model in step S130.
[0096] In case that the verifying the day-ahead scheduling results successes, the day-ahead scheduling results obtained in step S130 are regarded as final decision values of the power system and output; in case that the verifying the day-ahead scheduling results fails, a new round of iterating and updating is performed, which includes updating the day-ahead scheduling optimization model and repeatedly performing the steps from S120 to S140 until verifying the day-ahead scheduling results successes.
[0097] It should be noted that, the verifying the day-ahead scheduling results in this step is to correct day-ahead spare decision values of the power system, namely the day-ahead scheduling results, thereby ensuring the feasibility of day-ahead scheduling for the power system.
[0098] In this embodiment, by obtaining the power system prediction parameters in the to-be-scheduled time period; constructing the day-ahead scheduling optimization model and generating the multiple renewable energy power scenarios based on the power system prediction parameters; solving the day-ahead scheduling optimization model to obtain the day-ahead scheduling results; verifying the day-ahead scheduling results based on the power system prediction parameters and the multiple renewable energy power scenarios; the day-ahead scheduling results is output in case that the verifying the day-ahead scheduling results successes. In the method, the impact of the renewable energy station grid-connected proportion instructions on the renewable energy power scenarios is characterized by generating multiple renewable energy power scenarios, so that the decision-dependent uncertainty for renewable energy is taken into account in the day-ahead scheduling for power system, the voltage security for nodes in the power system is ensured by constructing the day-ahead scheduling optimization model, and the feasibility of intraday power grid operation is ensured by verifying the day-ahead scheduling result, which solves the problem that the decision-dependent uncertainty for renewable energy and the voltage security of power system are not fully considered in traditional power system scheduling modes, and the power system is safely and economically scheduled under the condition of voltage security.
[0099] On the basis of the above embodiment, the day-ahead scheduling optimization model is constructed based on the power system prediction parameters. In an embodiment, the day-ahead scheduling optimization model includes the objective function and the corresponding constraints, and constructing the day-ahead scheduling optimization model includes constructing the objective function for the power system day-ahead scheduling optimization problem and the objective constraints corresponding to the objective function.
[0100] The objective function (2) for the power system day-ahead scheduling optimization problem is as follows:
where is a set of scheduling time periods,
.sub.G is a set of thermal power units, c.sub.i.sup.g is a cost per unit power output, p.sub.i.sup.g(t) is active pre-output power of a thermal power unit i in a time period t, c.sub.i.sup.spare is a regulation spare cost for regulating up and down per unit, r.sub.i.sup.g,up(t) is an uphill capacity of the thermal power unit i in the time period t, r.sub.i.sup.g,dn(t) is a downhill capacity of the thermal power unit i in the time period t, w.sub.j.sup.pption(t) is a renewable energy station grid-connected proportion of a renewable energy station j in the time period t, p.sub.d.sup.dr(t) is a protocol capacity of a demand side response of a load d in the time period t, p.sub.j,y.sup.re,cut(t) is a renewable energy power reduction value of the renewable energy station j in the time period t, p.sub.j,y.sup.re(t) is a renewable energy power grid-connected value of the renewable energy station j in the time period t, p.sub.d,y.sup.load (t) is a load power supply value of the load d in the time period t, p.sub.d,y.sup.load,cut(t) is a demand side response usage value of the load d in the time period t, p.sub.i,y.sup.gc(t) is unit real-time active power output of the thermal power unit i in the time period t, q.sub.i,y.sup.gc(t) is unit real-time reactive power output of the thermal power unit i in the time period t, p.sub.k,y.sup.e,ch(t) is active charging power of an energy storage station k in a scenario y and the time period t, p.sub.k,y.sup.e,dc(t) is active discharging power of the energy storage station k in the scenario y and the time period t, E.sub.k,y(t) is stored energy of the energy storage station k in the scenario y and the time period t, q.sub.k,y.sup.e(t) is reactive power injected by the energy storage station to the power grid, p.sub.i,y.sup.brch(t) is reactive power flow of a transmission line l in the scenario y and the time period t, q.sub.l,y.sup.brch(t) is reactive power flow of the transmission line l in the scenario y and the time period t, s.sub.y.sup.1(t)s.sub.y.sup.2(t) are slack variables of active power balance in the power system, s.sub.y.sup.3 (t)s.sub.y.sup.4(t) are slack variables of reactive power balance in the power system, s.sub.y.sup.5(t)s.sub.y.sup.12(t) are line capacity slack variables considering active power flow and reactive power flow, v.sub.b,y.sup.amp (t) is a node voltage of a node b in the scenario y and the time period t, p.sub.b,y.sup.bus (t) is an active power input value of the node b in the scenario y and the time period t, q.sub.b,y.sup.bus(t) is a reactive power input value of the node b in the scenario y and the time period t, .sub.b,y(t) is a node phase angle value of the node b in the scenario y and the time period t, r.sub.i,y.sup.gc,use(t) is an auxiliary variable gc,use for obtaining the active power spare usage amount, q.sub.i,y.sup.gc,use(t) is an auxiliary variable for obtaining the reactive power spare usage amount, q.sub.k,y.sup.e,use(t) is an auxiliary variable for obtaining the reactive power spare usage amount of the energy storage station,
.sub.R is a set of the renewable energy stations, c.sub.j.sup.pption is a unit cost of the renewable energy station grid-connected proportion regulation instruction,
.sub.D is a set of the loads, c.sub.d.sup.dr is a cost of the demand side response per unit capacity,
.sub.Y.sup.n is a set of typical renewable energy scenarios, .sub.y is a variable of power system operating cost in the scenario y, d is an index of the loads, i is a thermal power unit number, j is an index of the renewable energy stations, k is an index of the energy storage stations, t is a scheduling time point, y is an index of the renewable energy scenarios, l is an index of the transmission lines, and |
.sub.Y.sup.n| is a number of elements included in the set of typical renewable energy scenarios
.sub.Y.sup.n.
[0101] Further, there are multiple objective constraints in the objective function, including objective constraints (3) to (52), which are expanded as follows.
1) Constraints (3) to (5) of Active Pre-Output, Ramp Up, and Ramp Down of the Thermal Power Unit:
where the variable p.sub.i.sup.g(t) represents the active pre-output power of the thermal power unit i in the time period t, the formulas (3) to (5) are constraints of the upper and lower limit of the pre-output of the thermal power unit, a constraint of the ramp up of the pre-output power of the thermal power unit, and a constraint of the ramp down of the pre-output power of the thermal power unit respectively.
2) Constraints (6) to (8) of Uphill Capacity and Downhill Capacity of the Thermal Power Unit:
where the variables r.sub.i.sup.g,up(t) and r.sub.i.sup.g,dn(t) are the uphill capacity and the downhill capacity of the thermal power unit i in the time period t respectively, the formula (6) is a constraint of relationship between the uphill capacity, the downhill capacity, and the pre-output of the thermal power unit, the formula (7) is a physical constraint of the uphill capacity of the thermal power unit, and the formula (8) is a physical constraint of the downhill capacity of the thermal power unit.
3) A Constraint (9) of Renewable Energy Station Grid-Connected Proportion:
where the variable w.sub.j.sup.pption(t) represents the renewable energy station grid-connected proportion of the renewable energy station j in the time period t, the formula (9) represents that decision on the variable w.sub.j.sup.pption(t) is made within the range from W.sub.j.sup.pption to
4) A Constraint (10) of Protocol Capacity of Demand Side Response:
where the variable p.sub.d.sup.dr(t) is the protocol capacity of the demand side response of the load d in the time period t,
5) Constraints (11) to (51) on Feasible Cut of the Day-Ahead Scheduling.
[0102] It should be noted that, some iteration parameters need to be used and n is denoted as the number of iterations in this embodiment, it is initialized that n=1.
[0103] In the process of an n-th iteration, the typical renewable energy scenario set used in the upper level is .sub.Y.sup.n, and the renewable energy power scenarios in
.sub.Y.sup.n are denoted as P.sub.j,t.sup.renew,y
(j=1, . . . ,N.sub.R,t=1, . . . ,N.sub.T,y=1, . . . ,|.sub.Y.sup.n|),
where y is an index of the renewable energy scenarios, and |.sub.Y.sup.n| is the number of elements included in the set |
.sub.Y.sup.n|.
[0104] In case that n=1, it is initialized that |.sub.Y.sup.n|=1, and the renewable energy output scenarios P.sub.j,t.sup.renew,y|.sub.y=1 (j=1, . . . , N.sub.R, t=1, . . . , N.sub.T) in
.sub.Y.sup.n is set to be .sub.m=1, . . . ,M.sub.j,t,m.sup.RP.sub.j,t,m.sup.R,.
[0105] In the n-th iteration, for each of the renewable energy output scenario P.sub.j,t.sup.renew,y (j=1, . . . , N.sub.R, t=1, . . . , N.sub.T) in .sub.Y.sup.n, the constraints (11) to (51) need to be added.
where in constraint (11), the variables p.sub.j,y.sup.re,cut(t) and p.sub.j,y.sup.re(t) are the renewable energy power reduction value and the renewable energy power grid-connected value of the renewable energy station j in the scenario y and the time period t.
[0106] The constraints (11) and (12) are a constraint of an interval of the renewable energy power reduction value and a constraint of a relationship between the renewable energy power reduction value, the renewable energy power grid-connected value, and the renewable energy active power scenario, respectively.
[0107] In the constraints (11) to (13), the vector w.sup.pption(t) is defined as w.sup.pption(t)=[w.sub.1.sup.pption(t), . . . , w.sub.j.sup.pption(t), . . . ,
(t)], and the function F.sub.j[w.sup.pption(t)] may be used to represent the different impacts of changes in grid-connected proportion instruction on the renewable energy active power output scenario of the renewable energy station j. The expression of the function F.sub.j[w.sup.pption(t)] is shown in the constraint (13).
[0108] In the constraint (13), the coefficient a.sub.j,e.sup.pption represents the impact of changes in grid-connected proportion instruction of a renewable energy station e on the renewable energy active power scenario of the renewable energy station j, the coefficient b.sub.j.sup.pption is the constant term coefficient of the function F.sub.j[w.sup.pption(t)].
where the variables P.sub.d,y.sup.load,cut(t) and p.sub.d,y.sup.load(t) are demand side response usage value and load power supply value of the load d in the scenario y and the time period t respectively, the constraint (14) is a constraint on an interval of the demand side response usage value, and the constraint (15) is a constraint on a relationship between the load power supply, the demand side response usage value and the load prediction value.
where the variable p.sub.i,y.sup.gc(t) represents real-time active power output of the thermal power unit i in the time period t, the constraints (16) and (17) are constraints of an interval of the real-time active power output of the thermal power unit, and the constraints (18) and (19) are constraints of a ramp up speed and a ramp down speed of the real-time active power output of the thermal power unit.
where the variable q.sub.i,y.sup.gc(t) represents the real-time reactive power output of the thermal power unit i in the period t, and the constraint (20) is a constraint of an interval of the real-time reactive power output of the thermal power unit.
where p.sub.k,y.sup.e,ch(t) represents active charging power of the energy storage station k in a scenario y and the time period t, p.sub.k,y.sup.e,dc(t) represents active discharging power of the energy storage station k in the scenario y and the time period t, E.sub.k,y(t) represents the stored energy of the energy storage station k in the scenario y and the time period t, and q.sub.k,y.sup.e(t) represents the reactive power injected by the energy storage station to the power grid.
[0109] The constraints (21) and (22) are constraints of a charging power range of the energy storage station and a discharging power range of the energy storage station respectively, the constraint (23) is a constraint of a time period coupling of the stored energy of the energy storage station, the constraint (24) is a constraint of an upper limit and a lower limit of the stored energy of the energy storage station, the constraint (25) is a constraint of a value of the stored electric quantity energy at the beginning and end of a day for the energy storage station, the constraint (26) is a constraint of a range of the reactive power injected by the energy storage station k to the power grid in the scenario y and the time period t, and the constraints (27) and (28) are constraints of operating ranges of the active power and the reactive power of the energy storage station.
where the variables p.sub.l,y.sup.brch(t) and q.sub.l,y.sup.brch(t) represent the active power flow and the reactive power flow of the transmission line l in the scenario y and the time period t, the variables s.sub.y.sup.1(t) and s.sub.y.sup.2(t) represent the slack variables of the active power balance in the power system, the variables s.sub.y.sup.3(t) and s.sub.y.sup.4(t) represent the slack variables of the reactive power balance in the power system, and the variables s.sub.y.sup.5(t)s.sub.y.sup.12(t) are the line capacity slack variables considering active power flow and reactive power flow.
[0110] Corresponding to the above variables, the constraints (29) and (30) are constraints of the active power balance in the power system and the reactive power balance in the power system respectively, the constraints (31) to (34) are capacity constraints of the transmission line considering active power flow and reactive power flow, and the constraints (35) to (36) are non-negative constraints of the slack variables.
where the variable v.sub.b.sup.amp(t) is the node voltage of the node b in the scenario y and the time period t, and the constraint (37) is an amplitude constraint of the node voltage.
where p.sub.b,y.sup.bus(t) and q.sub.b,y.sup.bus(t) represent the active power input value and the reactive power input value of the node b in the scenario y and the time period t, .sub.b,y(t) represents the node phase angle value of the node b in the scenario y and the time period t, and in .sub.b,y(t), a phase angle of a slack node is represented by .sub.slack,y(t).
[0111] The constraints (38) and (39) are constraints on the node active power and the node reactive power respectively, the constraint (40) is a constraint of a relationship between the node reactive power, the node voltage amplitude and the node voltage phase angle, the constraint (42) is a constraint of a relationship between the active power flow of the transmission line, the voltage amplitude of the starting and end nodes corresponding to the transmission line and the voltage phase angle of the starting and end nodes corresponding to the transmission line, the constraint (43) is a constraint of a relationship between the reactive power flow of the transmission line, the voltage amplitude of the starting and end nodes corresponding to the transmission line and the voltage phase angle of the starting and end nodes corresponding to the transmission line, and the constraint (44) is a constraint of an operation range of the node voltage phase angle.
[0112] The above formulas (37) to (44) are the voltage security constraints among the objective constraints. In an embodiment, a linear flow mode considering the power system active and reactive power flow is used to construct the voltage amplitude, the voltage phase angle and the constraint of the relationship between the active power and the reactive power of the power device, and the constraints of the voltage amplitude of node and the operation ranges of the voltage phase angle of the node are added, and through the day-ahead scheduling method for the power system according to the present embodiment, the security of the voltage amplitude and phase angle of the power system may be ensured.
[0113] Compared with the traditional optimization mode based on direct current (DC) power flow, this embodiment may better ensure the voltage security of the power system and satisfy the active power balance and reactive power balance of the power system simultaneously.
where the variables r.sub.i,y.sup.gc,use(t), q.sub.i,y.sup.gc,use(t) and q.sub.k,y.sup.e,use(t) are auxiliary variables for obtaining the active power spare usage amount, the reactive power usage amount and the reactive power usage amount of the energy storage station respectively.
[0114] The constraints (45) to (50) are constraints of auxiliary variables for calculating the active power spare usage amount, the reactive power spare usage amount, and the reactive power spare usage amount of the energy storage station for the thermal power unit.
where the variable .sub.y represents the power system operation cost in the scenario y.
[0115] The constraint (51) is a constraint equation for the power system intraday operation.
6) Reserve Tuning Causality Cutting Plane Set Constraint (52).
[0116] In the successive iterations of this embodiment, the lower level feeds back/transmits and updates the cutting plane set .sub.CUT.sup.n(t) to the upper level, and the variables p.sub.i.sup.g(t), r.sub.i.sup.g,up(t), r.sub.i.sup.g,dn(t), w.sub.j.sup.pption(t) and p.sub.d.sup.dr(t) need to satisfy the constraint shown in formula (52):
in case that n=1, .sub.CUT.sup.n(t) represent all the feasible region of the above decision variables; in case that n2, the expression of
.sub.CUT.sup.n(t) is referred to formula (107).
[0117] The above formulas (3) to (52) are the necessary objective constraints to solve the objective function.
[0118] It should be noted that, the objective function of the day-ahead optimization model is to minimize the thermal power unit pre-output power cost, the thermal power unit spare cost, the renewable energy grid-connected proportion instruction cost, the demand side response protocol cost and the scheduling cost.
[0119] In an embodiment, a preliminary expression of the objective function of the day-ahead optimization model is shown as formula (53).
[0120] On the basis of formula (53), the above constraints (3) to (52) are added, the following objective function may be obtained.
[0121] Decision values of the variables p.sub.i.sup.g(t), r.sub.i.sup.g,up(t), r.sub.i.sup.g,dn(t), w.sub.j.sup.pption(t) and p.sub.d.sup.dr(t) are denoted as {tilde over (P)}.sub.i.sup.g,n(t), {tilde over (R)}.sub.i.sup.g,up,n(t), {tilde over (R)}.sub.i.sup.g,dn,n(t), {tilde over (W)}.sub.j.sup.pption,n(t) and {tilde over (P)}.sub.d.sup.dr,n(t) respectively.
[0122] A footnote n is an index of the iteration number.
[0123] Subsequently, the upper level transmits the day-ahead scheduling results, namely {tilde over (P)}.sub.i.sup.g,n(t), {tilde over (R)}.sub.i.sup.g,up,n(t), {tilde over (R)}.sub.i.sup.g,dn,n(t), {tilde over (W)}.sub.j.sup.pption,n(t) and {tilde over (P)}.sub.d.sup.dr,n(t) to the lower level, and the lower level verifies the day-ahead scheduling results.
[0124] In this embodiment, by constructing the objective function for power system day-ahead scheduling optimization problem and the objective constraints corresponding to the objective function based on the power system prediction parameters; solving the corresponding day-ahead scheduling optimization model to obtain the day-ahead scheduling results; verifying the day-ahead scheduling results based on the power system prediction parameters and the multiple renewable energy power scenarios; and in case that the verifying the day-ahead scheduling results successes, the day-ahead scheduling results is output. In the method, the impact of the renewable energy station grid-connected proportion instructions on the renewable energy power scenarios is characterized by generating multiple renewable energy power scenarios, so that the decision-dependent uncertainty for renewable energy is considered in the day-ahead scheduling for power system, the voltage security for nodes in the power system is ensured by constructing the day-ahead scheduling optimization model, and the feasibility of intraday power grid operation is ensured by verifying the day-ahead scheduling result, which solves the problem that the decision-dependent uncertainty for renewable energy and the voltage security of power system are not fully considered in traditional power system scheduling modes, and the power system is safely and economically scheduled under the condition of voltage security.
[0125] On the basis of the above embodiment, verifying the day-ahead scheduling results based on the power system prediction parameters and the multiple renewable energy power scenarios includes: for each renewable energy power scenario, constructing the intraday scheduling optimization model based on the day-ahead scheduling results and the power system prediction parameters; solving the intraday scheduling optimization model to obtain a multi-stage optimal solution of the variable in the renewable energy power scenario; calculating penalty cost corresponding to the day-ahead scheduling results based on the multi-stage optimal solution of the variable; and verifying the day-ahead scheduling results based on the penalty cost.
[0126] It should be noted that, after the upper level transmits {tilde over (P)}.sub.i.sup.g,n(t), {tilde over (R)}g.sub.i.sup.g,up,n(t), {tilde over (R)}.sub.i.sup.g,dn,n (t), {tilde over (W)}.sub.j.sup.pption(t) and {tilde over (P)}.sub.d.sup.dr,n(t) to the lower level, and the middle level transmits the renewable energy power scenario set .sub.RO.sup.n to the lower level, a model of the intraday scheduling optimization problem for the power system may be constructed using a sequential evolution concept.
[0127] In the intraday scheduling for the power system, the scheduling center generally may only better obtain the renewable energy prediction active power output value in a limited time period. The number of time periods that may be predicted in the renewable energy scenario is denoted as T, the power system may predict the renewable energy output value from t.sub.now to t.sub.now+T within the time period t.sub.now, and a time period set from t.sub.now to t.sub.now+T is denoted as .sub.T.sup.NOW.
[0128] Therefore, for the renewable energy power scenario P.sub.j,t.sup.renew,z(j.sub.R, t
) in the set
.sub.RO.sup.n, observable renewable energy output values of the power system in the time period t.sub.now includes P.sub.j,t.sub.
[0129] In an application process, generally the error value of .sub.t.sub.
[0130] The intraday optimization problem for the power system is a multi-stage scheduling problem, that is, the decision variable in the time period t.sub.now may be affected by the decision value in the time period t.sub.now1.
[0131] An actual output value of the thermal power unit in time period t.sub.now1 is denoted as {tilde over (P)}.sub.i,z.sup.gc,n(t.sub.now1), a state of charge value of the energy storage station is denoted as {tilde over (E)}.sub.k,z.sup.n(t.sub.now1), constraints (55) to (94) need to be constructed for the spare scheduling problem in time period t.sub.now, and objective functions (95) to (96) need to be constructed, so that the constructed intraday scheduling optimization model is obtained.
[0132] The constraints included in the intraday scheduling optimization model are shown in detail below.
1) Real-Time Power Output Constraints (55) to (58) of the Thermal Power Unit:
where the variable p.sub.i,z.sup.gc(t) represents the active power of the thermal power unit i in the time period t, U.sub.i(t) is the node voltage of the thermal power unit i in an intraday time period t, P.sub.i.sup.gen is a lower limit of the active power output of the thermal power unit i,
[0133] The constraints (55) and (56) are constraints of intervals of the real-time power output of the thermal power unit, and constraints (57) and (58) are constraints of the ramp up and ramp down ratio of the real-time output of the thermal power unit.
2) Demand Side Response Usage Amount Constraints (59) to (60):
where the variables p.sub.d,z.sup.load,cut(t) and p.sub.d,z.sup.load(t) are the demand side response usage value and the load power supply value of the load d in the time period t respectively.
[0134] The constraints (59) and (60) are a constraint of an interval of the demand side response scheduling value and a constraint of a relationship between the load power supply value, the demand side response usage value and the load prediction value respectively.
[0135] Renewable energy power reduction value and power grid-connected value constraints (61) to (62):
where the variables p.sub.j,z.sup.re,cut(t) and p.sub.j,z.sup.re(t) are the renewable energy power reduction value and the power grid-connected value of the renewable energy station j in the time period t, .sub.t.sub.
[0136] The constraint (61) is a constraint of an interval of the renewable energy power reduction value, and the constraint (62) is a constraint of a relationship between the renewable energy power reduction value, the power grid-connected value and a renewable energy power generation scenario.
4) Reactive Power Constraint (63) of Thermal Power Unit:
where the variable q.sub.i,z.sup.gc(t) represents the unit real-time reactive power output of the thermal power unit i in the time period t, Q.sub.i.sup.gen is a lower limit of the reactive power of the thermal power unit i, {tilde over (Q)}.sub.i.sup.gen is an upper limit of the reactive power of the thermal power unit i.
[0137] The constraint (63) is a constraint of an interval of the unit real-time reactive power output.
5) Operation Constraints (64) to (71) of Energy Storage Station:
where p.sub.k,z.sup.e,ch(t) represents the charging power of the energy storage station k in the scenario z and the time period t, p.sub.k,z.sup.e,dc(t) represents the discharging power of the energy storage station k in the scenario z and the time period t, E.sub.k,z(t) represents the stored energy of the energy storage station k in the scenario z and the time period t, q.sub.k,z.sup.e(t) represents the reactive power injected to the power grid by the energy storage station, {tilde over (P)}.sub.k.sup.ess is the upper limit of active charging and discharging power of the energy storage station k, E.sub.k.sup.ess and .sub.k.sup.ess are the capacity upper limit and capacity lower limit of the energy storage station k,
[0138] The constraints (64) and (65) are constraints of ranges of charging power and discharging power of the energy storage station, the constraint (66) is a constraint of a time period coupling of the stored energy of the energy storage station, the constraint (67) is a constraint of the upper limit and lower limit of the stored energy, the constraint (68) is a constraint of a range of the reactive power injected to the power grid by the energy storage station k, and the constraints (69) and (70) are constraints of operation ranges of the active power and reactive power of the energy storage station.
[0139] It should be noted that, when scheduling time period t.sub.now=1, it needs to set that {tilde over (E)}.sub.k,z(0)=E.sub.k.sup.init. In a day-end scheduling time period, a numerical constraint of state of charge for the energy storage station needs to be considered, that is, when t.sub.now+TN.sub.T, the constraint (71) needs to be considered:
where the parameter E.sub.k.sup.end is a day-end energy value of the energy storage station k.
6) Power System Power Balance and Line Capacity Constraints (72) to (79):
where the variables brch (t) and brch (t) represent the active power flow and the reactive power flow of the transmission line l in the scenario z and the time period t, Q.sub.d,t.sup.D is the reactive power demand of the load d in the time period t, the variables s.sub.z.sup.1(t) and s.sub.z.sup.2(t) are slack variables of the active power balance in the power system, the variables s.sub.z.sup.3(t) and s.sub.z.sup.4(t) are slack variables of the reactive power balance in the power system, variables s.sub.z.sup.5(t)s.sub.z.sup.12(t) are line capacity slack variables considering active power flow and reactive power flow, and
[0140] Corresponding to the above variables, the constraint (72) is a constraint of the active power balance in the power system, the constraint (73) is a constraint of the reactive power balance in the power system, the constraints (74) to (77) are constraints of line capacity considering active power flow and reactive power flow, the constraint (78) is a non-negative constraint of slack variables s.sub.z.sup.1(t), s.sub.z.sup.2(t), s.sub.z.sup.3(t) and s.sub.z.sup.4(t), and the constraint (79) is a non-negative constraint of slack variables s.sub.z.sup.5(t)s.sub.z.sup.12(t).
where the variable v.sub.b.sup.amp(t) is the node voltage of the node b in the scenario z and the time period t.
[0141] The constraint (80) is an amplitude constraint of the node voltage.
where p.sub.b,z.sup.bus(t) and q.sub.b,z.sup.bus(t) represent the active power input value and the reactive power input value of the node b in the scenario z and the time period t, .sub.b,z(t) represent the node phase angle value of the node b in the scenario z and the time period t, and in .sub.b,z(t), a phase angle variable balancing the node is represented by .sub.slack,z(t).
[0142] The constraints (81) and (82) are constraints of the node active power and the node reactive power respectively, the constraint (83) is a constraint of a relationship between the node active power input value, the node voltage amplitude and the node voltage phase angle, the constraint (84) is a constraint of a relationship between the node reactive power, the node voltage amplitude and the node voltage phase angle, the constraint (85) is a constraint of a relationship between the active power flow of the transmission line, the voltage amplitude of the starting and end nodes corresponding to the transmission line and the voltage phase angle of the starting and end nodes corresponding to the transmission line, the constraint (86) is a constraint on a relationship between the reactive power flow of the transmission line, the voltage amplitude of the starting and end nodes corresponding to the transmission line and the voltage phase angle of the starting and end nodes corresponding to the transmission line, and the constraint (87) is a constraint on an operation range of the node voltage phase angle.
where the variables r.sub.i,z.sup.gc,use(t), q.sub.i,z.sup.gc,use(t) and q.sub.k,z.sup.e,use(t) are auxiliary variables for obtaining the active power spare usage amount, the reactive power usage amount and the reactive power usage amount of the energy storage station respectively.
[0143] The constraints (88) to (93) are constraints on auxiliary variables for calculating the active power spare usage amount, the reactive power usage amount, and the reactive power usage amount of the energy storage station for the thermal power unit.
where the variable .sub.z represents the power system operation cost in the scenario z.
[0144] The constraint (94) is a constraint equation for the power system intraday operation.
[0145] The above formulas (55) to (94) are the constraints for the intraday scheduling optimization model.
[0146] It should be noted that, the objective function of the intraday optimization time period t.sub.now is to minimize the system operation cost from t.sub.now to t.sub.now+T. In an embodiment, a preliminary expression of the objective function of the intraday scheduling optimization model is as follows.
[0147] On the basis of formula (95), the above constraints (55) to (94) are added, an overall expression for the optimization problem of the lower level in the time period t.sub.now is obtained, namely the objective function of the intraday scheduling optimization model.
[0148] It should be noted that, the meanings of some parameters in the intraday scheduling optimization model constraints (55) to (94) correspond to that of some parameters in the day-ahead scheduling optimization model constraints (3) to (52) each other, the intraday scheduling optimization model uses the letter z as a footnote, and the day-ahead scheduling optimization model uses the letter y as a footnote, so that the parameters in the constraints of both the intraday scheduling optimization model and the day-ahead scheduling optimization model can be distinguished. In case that the meaning of parameter misses in the former or the latter, the two may be referred to each other.
[0149] In the time period t.sub.now of the intraday optimization problem, an optimization problem (96) may be constructed and solved to obtain a multi-stage optimal solution of each variable from time period t.sub.now to t.sub.now+T.
[0150] In the intraday actual scheduling, the scheduling center needs to deploy decisions in the current time period for the power system, and the decisions in the subsequent time periods may be adjusted through further observations of uncertainty. Therefore, in the time period t.sub.now, the scheduling center may deploy the optimal solution when t=t.sub.now for the power system.
[0151] Through the above analysis, for all scheduling time period t.sub.now=1, . . . , N.sub.T in the power system intraday optimization problem, the optimization problem (96) is constructed and solved, and the optimal scheduling values of the current time period are recorded respectively, the multi-stage optimal solution of variables in the zth renewable energy scenario p.sub.j,t.sup.renew,z (j.sub.R, t
) may be obtained. In the multi-stage optimal solution, it may be denoted in the nth iteration that, the multi-stage optimal solution of the variables s.sub.z.sup.1(t)s.sub.z.sup.4(t) are {tilde over (S)}.sub.z.sup.1,n(t){tilde over (S)}.sub.z.sup.4,n(t), and the multi-stage optimal solution of the variables s.sub.l,z.sup.5(t)s.sub.l,z.sup.12(t) are {tilde over (S)}.sub.l,z.sup.5,n(t){tilde over (S)}.sub.l,z.sup.12,n(t).
[0152] In the intraday optimization problem (96) in the time period t, explicit expressions containing constraints {tilde over (P)}.sub.i.sup.g,n(t), {tilde over (R)}.sub.i.sup.g,up,n(t), {tilde over (R)}.sub.i.sup.g,dn,n(t), {tilde over (W)}.sub.j.sup.pption,n(t) and {tilde over (P)}.sub.d.sup.dr,n(t) are shown in (97) to (103):
where .sub.i,z.sup.1,n(t).sub.i,z.sup.4,n(t), .sub.d,z.sup.5,n(t) and .sub.j,z.sup.6,n(t) are dual variables of constraints (97) to (103) respectively.
[0153] After the intraday optimization problem (95) is solved, the value of the dual variables .sub.i,z.sup.1,n(t)i,z.sup.4,n(t), .sub.d,z.sup.5,n(t) and .sub.j,z.sup.6,n(t) may be denoted as {tilde over ()}.sub.i,z.sup.1,n(t){tilde over ()}.sub.i,z.sup.4,n(t), {tilde over ()}.sub.d,z.sup.5,n(t) and {tilde over ()}.sub.j,z.sup.6,n(t) (i, d, j, z, t, n).
[0154] Based on the above content, the day-ahead scheduling method for the power system provided by the embodiment further includes: in case that the verifying the day-ahead scheduling results fails, updating a cutting plane set based on the penalty cost corresponding to the day-ahead scheduling results; optimizing the day-ahead scheduling results based on an updated cutting plane set, and verifying an optimized day-ahead scheduling results; and in case that the verifying the optimized day-ahead scheduling results successes, outputting an optimized day-ahead scheduling results.
[0155] It should be noted that, the penalty cost of the scheduling center may be defined based on the optimal solution of the optimization problem (96): in the nth iteration, the penalty cost of the scheduling center in the scenario z and time period t may be defined as C.sub.z.sup.punish,n(t). An explicit expression of C.sub.z.sup.punish,n(t) is shown as formula (104):
for the scenario z in the set .sub.RO.sup.n, C.sub.z.sup.punish,n(t) (t
) may be obtained by calculating based on {tilde over (S)}.sub.z.sup.1,n(t){tilde over (S)}.sub.z.sup.4,n(t) and {tilde over (S)}.sub.l,z.sup.5,n(t){tilde over (S)}.sub.l,z.sup.12,n(t) (t
); [0156] in case that
C.sub.z.sup.punish,n(t)=0, it indicates that the calculation results {tilde over (P)}.sub.i.sup.g,n(t), {tilde over (R)}.sub.i.sup.g,up,n(t), {tilde over (R)}.sub.i.sup.g,dn,n(t), {tilde over (W)}.sub.j.sup.pption,n(t) and {tilde over (P)}.sub.d.sup.dr,n(t) of the upper level optimization problem (objective function) may ensure the feasibility of the scenario z. On the contrary, it indicates that the iteration result cannot ensure the feasibility of the scenario z.
[0157] In this embodiment, a convergence criterion (iteration termination criterion) is: a proportion of the number of the feasible scenarios in the lower level to the number N.sub.RO of the middle level renewable energy scenarios is greater than a preset value .sub.threshold.
[0158] In the nth iteration, the number of feasible renewable energy scenarios in the renewable energy scenario set .sub.RO is denoted as w.sub.feasible.sup.n, in case that the formula (105) is workable, the iteration ends, and the current {tilde over (P)}.sub.i.sup.g,n(t), {tilde over (R)}.sub.i.sup.g,up,n(t), {tilde over (R)}.sub.i.sup.g,dn,n(t), {tilde over (W)}.sub.j.sup.pption,n(t) and {tilde over (P)}.sub.d.sup.dr,n(t) are output as the decision result of the present application.
[0159] The formula (105) is as follows:
in case that the formula (105) does not be workable, the objective constraint (52) of the day-ahead scheduling optimization model is updated based on the decision values {tilde over (S)}.sub.z.sup.1,n(t){tilde over (S)}.sub.z.sup.4,n(t) and {tilde over (S)}.sub.l,z.sup.5,n(t){tilde over (S)}.sub.l,z.sup.12,n(t) (t) of all scheduling infeasible scenarios in the set
.sub.RO.sup.n, and the infeasible renewable energy scenarios in this iteration are added in
.sub.Y.sup.n+1, then let n=n+1 and proceed to the next round of iteration.
[0160] The update mode of the constraint (52) when the nth iteration ends is described below.
[0161] For the scenario z, in case that C.sub.z.sup.punish,n(t)>0, a cutting plane constraint of the upper level variables p.sub.i.sup.g(t), r.sub.i.sup.g,up(t), r.sub.i.sup.g,dn(t), w.sub.j.sup.pption(t) and p.sub.d.sup.dr(t) is constructed as formula (106).
[0162] Then, the formula (106) is added to the cutting plane set .sub.CUT.sup.n. After the nth iteration, the expression of
.sub.CUT.sup.n is shown as formula (107).
where |.sub.RO.sup.n| is the number of elements in a set
.sub.RO.sup.n.sup.
[0163] In this embodiment, for each renewable energy power scenario, by constructing the intraday scheduling optimization model based on the day-ahead scheduling results and the power system prediction parameters; solving the intraday scheduling optimization model and obtaining the multi-stage optimal solution of the variable in the renewable energy power scenario; calculating the penalty cost corresponding to the day-ahead scheduling results based on the multi-stage optimal solution of the variable; verifying the day-ahead scheduling results based on the penalty cost; in case that the verifying the day-ahead scheduling results fails, updating the cutting plane set based on the penalty cost corresponding to the day-ahead scheduling results; optimizing the day-ahead scheduling results based on the updated cutting plane set; verifying the optimized day-ahead scheduling results; and only in case that the verifying the optimized day-ahead scheduling results successes, the optimized day-ahead scheduling results are output. In the method, the impact of the renewable energy station grid-connected proportion instructions on the renewable energy power scenarios is characterized by generating multiple renewable energy power scenarios, so that the decision-dependent uncertainty for renewable energy is considered in the day-ahead scheduling for power system, the voltage security for nodes in the power system is ensured by constructing the day-ahead scheduling optimization model, and the feasibility of intraday power grid operation is ensured by verifying the day-ahead scheduling result, which solves the problem that the decision-dependent uncertainty for renewable energy and the voltage security of power system are not fully considered in traditional power system scheduling modes, and the power system is safely and economically scheduled under the condition of voltage security.
[0164] In addition,
[0165] As shown in
[0166] Secondly, iteration parameters are configured and an initialized. In an embodiment, the number of iterations is initialized as n=1, and upper level renewable energy typical scenario sets are configured and an initialized, that is, in the nth iteration, the renewable energy typical scenario sets used by the upper level are .sub.Y.sup.n and
.sub.Y.sup.n, where renewable energy power scenarios are denoted as P.sub.j,t.sup.renew,y (j=1, . . . , N.sub.R, t=1, . . . , N.sub.T, y=1, . . . , |
.sub.Y.sup.n|), y is an index of the renewable energy scenarios, and |
.sub.Y.sup.n| is the number of elements included in the set
.sub.Y.sup.n.
[0167] In case that n=1, it is initialized that |.sub.Y.sup.n|=1, and renewable energy output scenarios P.sub.j,t.sup.renew,y|.sub.y=1 (j=1, . . . , N.sub.R, t=1, . . . , N.sub.T) in
Y.sup.1 are configured as .sub.m=1, . . . ,M.sub.j,t,m.sup.RP.sub.j,t,m.sup.R,.
[0168] Thirdly, an upper level is used for solving a day-ahead scheduling optimization problem for the power system, in the nth iteration, the day-ahead scheduling optimization problem (54) for the power system is solved to obtain the day-ahead scheduling results {tilde over (P)}.sub.i.sup.g,n(t), {tilde over (R)}.sub.i.sup.g,up,n(t), {tilde over (R)}.sub.i.sup.g,dn,n(t), {tilde over (W)}.sub.j.sup.pption,n(t) and {tilde over (P)}.sub.d.sup.dr,n(t), and the day-ahead scheduling results are transmitted to a lower level optimization problem.
[0169] Fourthly, a middle level is used for generating random renewable energy scenarios, that is, in the nth iteration, generating random renewable energy power scenarios.
[0170] Fifthly, a lower level is used for solving the intraday scheduling optimization problem in the power system, that is, in the nth iteration, constructing and solving the day-ahead scheduling optimization problem shown in formula (96).
[0171] Sixthly, whether the day-ahead scheduling results transmitted by the upper level are output is determining based on an iteration termination criterion, namely formula (105).
[0172] In case that formula (105), the calculation ends and the decision values are output directly, namely the day-ahead scheduling results {tilde over (P)}.sub.i.sup.g,n(t), {tilde over (R)}.sub.i.sup.g,up,n(t), {tilde over (R)}.sub.i.sup.g,dn,n(t), {tilde over (W)}.sub.j.sup.pption,n(t) and {tilde over (P)}.sub.d.sup.dr,n(t) transmitted by the upper later.
[0173] In case that the formula (105) does not be workable, the cutting plane constraint (106) is generated based on the day-ahead scheduling result, the set (107) is updated, the renewable energy typical scenario set of the upper level is updated, and let n=n+1 and proceed to the next round of iteration.
[0174] Based on the above description, the day-ahead scheduling method for the power system provided by the present application is summarized as follows. [0175] (1) In terms of characterizing the uncertainty of renewable energy, the present application generates typical renewable energy power scenarios based on a probability distribution of renewable energy in each intraday time period to characterize the uncertainty of renewable energy. At the same time, the present application refers to an impact of the two instructions, namely the renewable energy station grid-connected proportion and renewable energy station output upper limit, issued by the scheduling center to the renewable energy station on the uncertainty of renewable energy in extremely high penetration of renewable energy power systems: the typical renewable energy power scenarios may change with changes in the two instructions, which may effectively reflect the changes in renewable energy power with decision instructions, and reflect the decision-dependent uncertainty of renewable energy output power. [0176] (2) In terms of characterizing the voltage security of power system, different from the DC power flow model used in the prior art, a linear flow involving active and reactive power is incorporated into the day-ahead scheduling optimization model of the present application. By adding the linear flow and the voltage security constraints to the day-ahead scheduling model, the voltage security of nodes may be ensured while ensuring the balance of demand and supply of active and reactive power in the power system. [0177] (3) In terms of causal modeling of power system decision process, the operational constraints of each device in sequentially disclosed renewable energy scenario, the active and reactive power balance of power system scheduling, and the limit of apparent power of line capacity are fully taken into account in the intraday multi-stage scheduling process for the power system of the present application, and a sequential evolution mode and a cutting plane construction mode are constructed to correct the power system day-ahead spare decision value to ensure the feasibility of intraday scheduling for the power system.
[0178]
[0179] As shown in
[0185] In this embodiment, by obtaining the power system prediction parameters in the to-be-scheduled time period by the power system prediction parameter obtaining module 310; constructing the day-ahead scheduling optimization model and generating the multiple renewable energy power scenarios based on the power system prediction parameters by the renewable energy power scenario generating module 320; solving the day-ahead scheduling optimization model to obtain the day-ahead scheduling results by the day-ahead scheduling optimization model solving module 330; verifying the day-ahead scheduling results based on the power system prediction parameters and the multiple renewable energy power scenarios by the day-ahead scheduling results verifying module 340; and in case that the verifying the day-ahead scheduling results successes, the day-ahead scheduling results is output by the day-ahead scheduling results outputting module 350. In the apparatus, the impact of the renewable energy station grid-connected proportion instructions on the renewable energy power scenarios is characterized by generating multiple renewable energy power scenarios, so that the decision-dependent uncertainty for renewable energy is considered in the day-ahead scheduling for power system, the voltage security for nodes in the power system is ensured by constructing the day-ahead scheduling optimization model, and the feasibility of intraday power grid operation is ensured by verifying the day-ahead scheduling result, which solves the problem that the decision-dependent uncertainty for renewable energy and the voltage security of power system are not fully taken into account in traditional power system scheduling modes, and the power system is safely and economically scheduled under the condition of voltage security.
[0186] It should be noted that, the day-ahead scheduling apparatus for the power system provided by the present application and the above-described day-ahead scheduling method for the power system may be referred to each other, and the similar part is not repeated.
[0187]
[0193] In addition, if the logical instructions in storage 430 described above is implemented in the form of a software functional unit and sold or used as an independent product, it may be stored in a computer readable storage medium. Based on such understanding, the solutions of the present application in essence or a part of the solutions that contributes to the related art, or all or part of the solutions, may be embodied in the form of a software product, which is stored in a storage medium, including several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods described in the respective embodiments of the present application. The storage medium described above includes various media that may store program codes, such as USB flash disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), magnetic disk, or optical disk.
[0194] The present application further provides a non-transitory computer readable storage medium storing a computer program that, when executed by a processor, causes the processor to perform the day-ahead scheduling method for the power system provided by the above embodiments, the method includes: [0195] obtaining power system prediction parameters in a to-be-scheduled time period, where the power system prediction parameters include thermal power unit parameters, renewable energy station parameters, load parameters, energy storage station (ESS) parameters, node parameters, a transmission line parameter and other power gird parameters; [0196] constructing a day-ahead scheduling optimization model and generating multiple renewable energy power scenarios based on the power system prediction parameters; [0197] solving the day-ahead scheduling optimization model to obtain day-ahead scheduling results; [0198] verifying the day-ahead scheduling results based on the power system prediction parameters and the multiple renewable energy power scenarios; and [0199] in case that the verifying the day-ahead scheduling results successes, outputting the day-ahead scheduling results.
[0200] The apparatus embodiment described above is only schematic, the units described as separate components may or may not be physically separated, the components shown as units may or may not be physical units, that is, they may be located in one place, or may be distributed to multiple network units. Some or all of the modules may be selected according to actual needs to achieve the objective of this embodiment. Those of ordinary skill in the art may appreciate and implement without any creative effort.
[0201] Through the above description of the embodiments, those of ordinary skill in the art may clearly understand that each embodiment may be implemented by software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on such understanding, the solutions of the present application in essence or a part of the solutions that contributes to the related art, or all or part of the solutions, may be embodied in the form of a software product, which is stored in a computer readable storage medium, such as ROM/RAM, magnetic disk, optical disk, etc., including several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods described in the respective embodiments of the present application.
[0202] It should be noted that, the above embodiments are only used to illustrate the technical solution of the present application, but not to limit it; although the present application is described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent substitutions for some of the technical features; and these modifications or substitutions do not deviate from the essence of the corresponding technical solutions from the scope of the technical solutions of each embodiment of the present application.