Method and system for configuring regenerative braking energy recovery devices in urban rail transit

Abstract

A method and system for configuring regenerative braking energy recovery devices in urban rail transit provided by the present application, successively including the following steps: calculating a preliminarily configured capacity P.sub.n of a regenerative braking energy recovery device predetermined for the traction substation n, then obtaining an optimally configured capacity Q.sub.n of the regenerative braking energy recovery devices; further, configuring the total number of the regenerative braking energy recovery devices; finally, configuring the type of the regenerative braking energy recovery devices. By reasonably configure the capacity and number of regenerative braking energy recovery devices in traction substations, the configuring method of the present application allows the regenerative braking energy generated by a train during braking to be completely absorbed, thus reduce the energy consumption of braking resistors. Meanwhile, the waste of idle regenerative braking energy recovery devices is avoided, and the acquisition cost of devices is reduced. By reasonably configuring the type of regenerative braking energy recovery devices, the deficiencies of a single regenerative braking energy recovery device can be avoided.

Claims

1. A method for configuring regenerative braking energy recovery devices in urban rail transit, successively comprising the following steps: S1: first, performing train traction simulation and calculation, further performing train power supply simulation and calculation according to the result of the train traction simulation and calculation to obtain a regenerative braking power S.sub.n(t) of a traction substation n, and calculating a preliminarily configured capacity P.sub.n of a regenerative braking energy recovery device predetermined for the traction substation n according to the regenerative braking power S.sub.n(t) of the traction substation n, wherein n ∈{1, 2, 3, . . . N}, and N is the total number of traction substations; wherein the step S1 comprises the following steps: S11: the train traction simulation and calculation: obtaining a traction energy consumption-velocity curve, a regenerative braking energy-velocity curve by a traction simulation algorithm of a traction simulation and calculation module through vehicle information parameters, dynamic performance parameters, resistance parameters, traction characteristic parameters and electric braking characteristic parameters; S12: the train power supply simulation and calculation: obtaining the regenerative braking power S.sub.n(t) of the traction substation n by a power supply simulation algorithm of a power supply simulation and calculation module according to the traction energy consumption-velocity curve and the regenerative braking energy-velocity curve obtained by the traction simulation and calculation module and in combination with the impedance parameters of a power supply line, location parameters and capacity of the traction substation, number of departure; S13: preliminary configuration and calculation of the capacity of the regenerative braking energy recovery devices: performing preliminary configuration for the capacity of the regenerative braking energy recovery device of the traction substation n according to the obtained regenerative braking power S.sub.n(t) of the traction substation n; S2: according to the preliminarily configured capacity P.sub.n of the regenerative braking energy recovery devices and in combination with the specification of the existing regenerative braking energy recovery devices, considering that when a regenerative braking energy recovery device is failed, adjacent regenerative braking energy recovery devices is capable to completely absorb the regenerative braking energy to be absorbed by the failed regenerative braking energy recovery device, performing capacity optimal configuration for the regenerative braking energy recovery devices to obtain an optimally configured capacity Q.sub.n, of the regenerative braking energy recovery devices corresponding to the traction substation n; wherein the step S2 comprises the following steps: S21: converting an actually configured capacity Z.sub.n according to the preliminarily configured capacity P.sub.n of the regenerative braking energy recovery devices and the specification of the existing regenerative braking energy recovery devices; S22: determining when a regenerative braking energy recovery device is failed, whether adjacent regenerative braking energy recovery devices is capable to completely absorb the regenerative braking energy to be absorbed by the failed regenerative braking energy recovery device, if so, the actually configured capacity of the adjacent regenerative braking energy recovery devices is an optimally configured capacity, and, if not, increasing the capacity of the adjacent regenerative braking energy recovery devices by an integral time of the capacity unit value of the regenerative braking energy recovery devices, to obtain optimally configured capacity of the adjacent regenerative braking energy recovery devices; S3: performing configuration for the total number M of the regenerative braking energy recovery devices installed according to the optimally configured capacity Q.sub.n, of the regenerative braking energy recovery devices; wherein the step S3 comprises the following steps: S31: determining whether the optimally configured capacity Q.sub.n of the regenerative braking energy recovery device corresponding to the traction substation n is less than two times of the capacity unit value of the regenerative braking energy recovery devices, if so, removing the regenerative braking energy recovery device from the traction substation n, and, if not, installing the regenerative braking energy recovery device in the traction substation n according to the optimally configured capacity Q.sub.n; S32: obtaining the actual total number M of the regenerative braking energy recovery devices installed and the actual total configured capacity $\underset{n=1}{\overset{N}{.Math.}}{Q}_n$ of the regenerative braking energy according to the result determined in the S31, wherein, an optimally configured capacity that is less than two times of the capacity unit value of the regenerative braking energy recovery devices is not included in Q.sub.n; S4: according to the magnitude of the optimally configured capacity Q.sub.n, and the total number M of the regenerative braking energy recovery devices installed as well as the locations of the regenerative braking energy recovery devices, further performing configuration for the type of the regenerative braking energy recovery devices of the traction substation n; wherein the step S4 comprises the following steps: S41: calculating an average capacity $E=\underset{n=1}{\overset{N}{.Math.}}{Q}_n/M$ of the regenerative braking energy recovery devices according to the result of calculation in the S32; S42: determining whether the traction substation n is adjacent to a main substation, if so, configuring the regenerative braking energy recovery device corresponding to the traction substation n as an energy storage unit, and, if not, performing S43; S43: determining whether the optimally configured capacity Q.sub.n of the regenerative braking energy recovery device corresponding to the traction substation n is less than the average capacity E, if so, configuring the regenerative braking energy recovery device of the traction substation n as an energy storage unit, and, if not, configuring regenerative braking energy recovery device of the traction substation n as an energy feedback unit.

2. The method for configuring regenerative braking energy recovery devices in urban rail transit according to claim 1, wherein the step S13 comprises the following steps: S131: obtaining regenerative braking power S.sub.nx(t) corresponding to different departure intervals x according to the regenerative braking power S.sub.n(t) of the traction substation n calculated by the train power supply simulation and calculation, where x ∈{1, 2, 3, . . . X}, X denotes the number of departure intervals x, and the departure intervals x are related to a subway operation plan; S132: according to the regenerative braking power S.sub.nx(t) under different departure intervals x, obtaining an aggregate of valid values S.sub.Tnx of the regenerative braking power within different continuous periods of time T under the corresponding departure interval x of the traction substation n, where T is related to the running velocity of the train; S133: obtaining the valid value of the maximum regenerative braking power P.sub.nx within different continuous periods of time T under the corresponding departure interval x according to the aggregate of valid values S.sub.Tnx; S134: obtaining the preliminarily configured capacity P.sub.n, of the regenerative braking energy recovery device corresponding to the traction substation n, where P.sub.n=Max {P.sub.n1, P.sub.n2, P.sub.nx, P.sub.nx}.

3. The method for configuring regenerative braking energy recovery devices in urban rail transit according to claim 1, wherein the step S22 comprises the following steps: S221: according to the S13, obtaining the preliminarily configured capacity P.sub.n, the departure interval x and the valid value of the maximum regenerative braking power P.sub.nx within different continuous periods of time T under the corresponding departure interval x of the failed regenerative braking energy recovery device, meanwhile, obtaining valid values of the maximum regenerative braking power of the adjacent regenerative braking energy recovery devices P.sub.(n−1)x and P.sub.(n+1)x within different continuous periods of time T under the corresponding departure interval x; S222: determining whether Z.sub.n−1+Z.sub.n+1≥P.sub.(n−1)x+P.sub.nx+P.sub.(n+1)x is true, if so, the actually configured capacity Z.sub.n−1 and Z.sub.n−1 of adjacent traction substations n−1 and n+1 remain unchanged, and, if not, perform S223; S223: determining the magnitude of the distances from the traction substation n respectively to the adjacent traction substation n−1 and to the adjacent traction substation n+1 L.sub.n(n−1) and L.sub.n(n+1); if L.sub.n(n−1)≤L.sub.n(n+1), increasing the actually configured capacity Z.sub.n+1 of the traction substation n+1 by an integral time of the capacity unit value of the regenerative braking energy recovery devices to obtain an optimally configured capacity Q.sub.n+1, and the optimally configured capacity Q.sub.n−1 of the traction substation n−1 is the actually configured capacity Z.sub.n−1; if L.sub.n(n−1)≥L.sub.n(n+1), increasing the actually configured capacity Z.sub.n−1 of the traction substation n−1 by an integral time of the capacity unit value of the regenerative braking energy recovery devices to obtain an optimally configured capacity Q.sub.n−1, and the optimally configured capacity Q.sub.n+1 of the traction substation n+1 is the actually configured capacity Z.sub.n+1.

4. The method for configuring regenerative braking energy recovery devices in urban rail transit according to claim 1, wherein the step S22 comprises the following steps: S221: according to the step S13, obtaining the preliminarily configured capacity P.sub.n−1 and P.sub.n+1 of the adjacent failed regenerative braking energy recovery devices, and according to the method in S21, converting the actually configured capacity Z.sub.n−1 and Z.sub.n+1 of the two; S222: determining whether Z.sub.n−1+Z.sub.n+1≥P.sub.n−1+P.sub.n+P.sub.n+1 is true, if so, the actually configured capacity Z.sub.n−1 and Z.sub.n+1 of adjacent traction substations n−1 and n+1 remain unchanged, and, if not, perform S223; S223: determining the magnitude of the distances from the traction substation n respectively to the adjacent traction substation n−1 and to the adjacent traction substation n+1 L.sub.n(n−1) and L.sub.n(n+1); if L.sub.n(n−1)≥L.sub.n(n+1), increasing the actually configured capacity Z.sub.n+1 of the traction substation n+1 by an integral time of the capacity unit value of the regenerative braking energy recovery devices to obtain an optimally configured capacity Q.sub.n+1, and the optimally configured capacity Q.sub.n−1 of the traction substation n−1 is the actually configured capacity Z.sub.n−1; and, if L.sub.n(n−1)≤L.sub.n(n+1), increasing the actually configured capacity Z.sub.n−1 of the traction substation n−1 by an integral time of the capacity unit value of the regenerative braking energy recovery devices to obtain an optimally configured capacity Q.sub.n−1, and the optimally configured capacity Qn+1 of the traction substation n+1 is the actually configured capacity Z.sub.n+1.

5. The method for configuring regenerative braking energy recovery devices in urban rail transit according to claim 1, wherein the step S3 comprises the following steps: S31: determining whether the optimally configured capacity Q.sub.n of the regenerative braking energy recovery device corresponding to the traction substation n is less than the capacity unit value of the regenerative braking energy recovery devices, if so, removing the regenerative braking energy recovery device from the traction substation n, and, if not, installing the regenerative braking energy recovery device in the traction substation n according to the optimally configured capacity Q.sub.n; S32: obtaining the actual total number M of the regenerative braking energy recovery $\underset{n=1}{\overset{N}{.Math.}}{Q}_n$ devices installed and the actual total configured capacity of the regenerative braking energy recovery devices according to the result determined in the S31, wherein, an optimally configured capacity that is less than the capacity unit value of the regenerative braking energy recovery devices is not included in Q.sub.n.

6. The method for configuring regenerative braking energy recovery devices in urban rail transit according to claim 1, wherein, the vehicle information parameters comprise vehicle type, marshaling and load; the dynamic performance parameters comprise the acceleration and deceleration of the vehicle; the resistance parameters comprise starting resistance and basic resistance; the traction characteristic parameters comprise traction force; and, the electric braking characteristic parameters comprise electric braking force.

7. The method for configuring regenerative braking energy recovery devices in urban rail transit according to claim 1, wherein, in S22, increasing the capacity of the adjacent regenerative braking energy recovery devices by one time of the capacity unit value.

8. A system for configuring regenerative braking energy recovery devices in urban rail transit, wherein, the system comprises a preliminary configurating unit, a capacity optimally configuring unit, a total number configurating unit and a type configurating unit; the preliminary configurating unit is configured to perform train traction simulation and calculation, further to perform train power supply simulation and calculation according to the result of train traction simulation and calculation to obtain a regenerative braking power S.sub.n(t) of a traction substation n, and calculate a preliminarily configured capacity P.sub.n of regenerative braking energy recovery device predetermined for the traction substation n according to the regenerative braking power S.sub.n(t) of the traction substation n, where n ∈{1, 2, 3, . . . X} and N is the total number of traction substations; the capacity optimally configuring unit is configured to perform capacity optimal configuration for the regenerative braking energy recovery devices to obtain an optimally configured capacity Q.sub.n of the regenerative braking energy recovery devices corresponding to the traction substation n, according to the preliminarily configured capacity P.sub.n of regenerative braking energy recovery devices and in combination with the specification of the existing regenerative braking energy recovery devices and by considering that when a regenerative braking energy recovery device is failed, adjacent regenerative braking energy recovery devices are capable to completely absorb the regenerative braking energy to be absorbed by the failed regenerative braking energy recovery device; the total number configurating unit is configured to perform configuration for the total number M of the regenerative braking energy recovery devices installed according to the optimally configured capacity Q.sub.n, of the regenerative braking energy recovery devices; the type configurating unit is configured to further perform configuration for the type of the regenerative braking energy recovery devices of the traction substation n, according to the optimally configured capacity Q.sub.n, and the total number M of the regenerative braking energy recovery devices installed as well as the locations of the regenerative braking energy recovery devices.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a flow chart of configuring regenerative braking energy recovery devices in urban rail transit according to one embodiment of the present application;

(2) FIG. 2 is a flow chart of preliminarily configuring capacity of regenerative braking energy recovery devices in urban rail transit according to one embodiment of the present application;

(3) FIG. 3 is a flow chart of S13 in FIG. 2;

(4) FIG. 4 is a flow chart of optimally configuring the capacity of the regenerative braking energy recovery devices in urban rail transit according to one embodiment of the present application;

(5) FIG. 5 is a flow chart of configuring the number and the type of the regenerative braking energy recovery devices in urban rail transit according to one embodiment of the present application;

(6) FIG. 6 is a schematic diagram of the system for the regenerative braking energy recovery devices in urban rail transit according to one embodiment of the present application.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

(7) In the following, the present application will be described in detail through exemplary implementations. However, it should be understood, without further recitation, the elements, structure and features in one implementation may be beneficially combined in other implementations without further recitation.

(8) As shown in FIG. 1, the present application provides a method for configuring regenerative braking energy recovery devices in urban rail transit, successively comprising the following steps:

(9) S1: First, train traction simulation and calculation is performed, train power supply simulation and calculation is further performed according to the result of the train traction simulation and calculation to obtain a regenerative braking power S.sub.n(t) of a traction substation n, and a preliminarily configured capacity P.sub.n of a regenerative braking energy recovery device predetermined for the traction substation n is calculated according to the regenerative braking power S.sub.n(t) of the traction substation n, wherein n∈{1, 2, 3, . . . N}, and N is the total number of traction substations.

(10) S2: According to the preliminarily configured capacity P.sub.n of the regenerative braking energy recovery devices and in combination with the specification of the existing regenerative braking energy recovery devices, considering that when a regenerative braking energy recovery device is failed, adjacent regenerative braking energy recovery devices is capable to completely absorb the regenerative braking energy to be absorbed by the failed regenerative braking energy recovery device, the capacity optimal configuration for the regenerative braking energy recovery devices is performed to obtain an optimally configured capacity Q.sub.n of the regenerative braking energy recovery devices corresponding to the traction substation n.

(11) S3: Configuration for the total number M of the regenerative braking energy recovery devices installed is performed according to the optimally configured capacity Q.sub.n of the regenerative braking energy recovery devices.

(12) S4: According to the optimally configured capacity Q.sub.n and the total number M of the regenerative braking energy recovery devices installed as well as the locations of the regenerative braking energy recovery devices, configuration for the type of the regenerative braking energy recovery devices of the traction substation n is further performed.

(13) Wherein, preferably, one regenerative braking energy recovery device is installed in each of the traction substations. In the method for configuring regenerative braking energy recovery devices in urban rail transit provided by the present application, by reasonably configuring the capacity and number of the regenerative braking energy recovery devices in the traction substations, so that the regenerative braking energy generated by a train during braking can be completely absorbed, and the energy consumption of braking resistors is greatly reduced. Accordingly, the better energy saving effect is achieved, the waste of idle regenerative braking energy recovery devices is avoided, and the acquisition cost of devices is reduced. By reasonably configuring the type of the regenerative braking energy recovery devices, the deficiencies of the single regenerative braking energy recovery device can be avoided.

(14) As shown in FIG. 2, the step S comprises the following steps.

(15) S11: The train traction simulation and calculation: characteristic curves comprising a traction energy consumption-velocity curve, a regenerative braking energy-velocity curve, a velocity-running time curve and a regenerative braking energy-velocity curve are obtained by a traction simulation algorithm of a traction simulation and calculation module through vehicle information parameters, dynamic performance parameters, resistance parameters, traction characteristic parameters and electric braking characteristic parameters, wherein the vehicle information parameters comprise vehicle type, marshaling and load; the dynamic performance parameters comprise the acceleration and deceleration of the vehicle; the resistance parameters comprise starting resistance and basic resistance; the traction characteristic parameters comprise traction force; and, the electric braking characteristic parameters comprise electric braking force.

(16) The traction simulation and calculation can be performed by means of the existing urban rail transit traction calculation software or the developed special software to output the curves, and will not be detailed here.

(17) S12: The train power supply simulation and calculation: by a power supply simulation algorithm of a power supply simulation and calculation module, the regenerative braking power S.sub.n(t) of the traction substation n is obtained preferably according to the traction energy consumption-velocity curve and the regenerative braking energy-velocity curve calculated by the traction simulation and calculation module and in combination with the impedance parameters of a power supply line, location parameters and capacity of the traction substation, number of departure, etc.

(18) The power supply simulation and calculation above can be performed by means of the existing urban rail transit power supply calculation software or the jointly developed special software, and will not be detailed here.

(19) The existing urban rail transit power supply simulation and analysis software includes EMM from the Carnegie-Mellon university, SINANET and OPEN TRACK & POWER NET from the ELBAS Company, RAILPOWER from the Balfour Beatty Company, urban rail transit power supply simulation software URTPS, etc.

(20) S13: Preliminary configuration and calculation of the capacity of the regenerative braking energy recovery devices: preliminary configuration for the capacity of the regenerative braking energy recovery device of the traction substation n is performed according to the obtained regenerative braking power S.sub.n(t) of the traction substation n.

(21) As shown in FIG. 3, the step S13 comprises the following steps.

(22) S131: Regenerative braking power S.sub.nx(t) corresponding to different departure intervals x is obtained according to the regenerative braking power S.sub.n(t) of each traction substation calculated by the train power supply simulation and calculation, where x∈{1, 2, 3, . . . X}, X denotes the number of departure intervals x, and the departure intervals x are related to a subway operation plan.

(23) It is to be noted that the “departure interval” refers to the time interval between departure of the last train and the next train, in seconds or minutes. The smaller the value of the departure interval is, the higher the departure frequency is. The departure intervals of domestic urban rail transit trains vary from two minutes to more than ten minutes. When the value of x in the “departure interval x” is different, that is, “departure interval 1”, “departure interval 2” . . . “departure interval X” refer to different departure intervals (which can also be interpreted as “the first departure interval”, “the second departure interval” . . . “the Xth departure interval”), different departure interval x have different departure interval values.

(24) In this step, every time one departure interval x is set, one train power supply simulation and calculation is performed to obtain the corresponding regenerative braking power S.sub.nx(t) under a different departure interval x.

(25) S132: According to the regenerative braking power S.sub.nx(t) under different departure intervals x, an aggregate of valid values S.sub.Tnx of the regenerative braking power within different continuous periods of time T under corresponding departure interval x of the traction substation n is obtained, where T is related to the maximum running velocity of the train;

(26) wherein, under the departure interval x, the valid value of the regenerative braking power of the traction substation n within different continuous periods of time T is:

(27) $s_{nx}=\sqrt{\frac{1}{T}{\int }_a^{a+T}{s_{nx}\left(t\right)}^{2}dt},$

(28) in which, T is related to the maximum running velocity of the train and is generally 15 s to 35 s. Thus, the aggregate of valid values S.sub.Tnx of the regenerative braking power of the traction substation n within different continuous periods of time T under the corresponding departure interval x is obtained. Here, the continuous period of time T may be interpreted as the feedback time of the regenerative braking energy. If the maximum running velocity of the train is higher, under the same braking force, a longer time is required for braking, and the feedback time of the regenerative braking energy is longer. The continuous period of time T is positively related to the braking time of the train and also related to the maximum running velocity of the train.

(29) S133: The valid value of the maximum regenerative braking power P.sub.nx within different continuous periods of time T under the corresponding departure interval x is obtained according to the aggregate of valid values S.sub.Tnx.

(30) S134: The preliminarily configured capacity P.sub.n of the regenerative braking energy recovery device corresponding to the traction substation n is obtained, where P.sub.n=Max {P.sub.n1, P.sub.n2, . . . , P.sub.nx, . . . , P.sub.nX}.

(31) During the preliminary configuring of the capacity of the regenerative energy recovery devices, the influence from the departure interval x is taken into consideration, and the difference in the departure interval x directly influences the distribution of the generative braking energy on the entire line; and, the valid value of the regenerative braking power S.sub.nx within a continuous period of time T is taken into consideration, and T is selected according to actual maximum velocity of the train and directly influences the amount of the regenerative braking energy during the braking process of a single train. By considering the departure interval x and the continuous period of time T, the practicability and scientific nature of the capacity configuration of the regenerative energy recovery devices are ensured.

(32) As shown in FIG. 4, the step S2 comprises the following steps.

(33) S21: An actually configured capacity Z.sub.n is converted according to the preliminarily configured capacity P.sub.n of the regenerative braking energy recovery devices and the specification of the existing regenerative braking energy recovery devices.

(34) Based on the actual manufacturing and industrial standards, the capacity unit value of the existing regenerative braking energy recovery devices is generally 500 kW, and the capacity of a single regenerative braking energy recovery device is generally 0.5 MW, 1 MW, 1.5 MW, 2 MW, 2.5 MW, 3 MW, 3.5 MW and 4 MW. The capacity conversion principle follows the principle of rounding to nearest. For example, if the preliminarily configured capacity is 2.665 MW, the capacity is converted to 2.5 MW; and, if the preliminarily configured capacity is 2.825 MW, the capacity is converted to 3 MW.

(35) S22: When a regenerative braking energy recovery device is failed, whether adjacent regenerative braking energy recovery devices is capable to completely absorb the regenerative braking energy to be absorbed by the failed regenerative braking energy recovery device is determined; if so, the actually configured capacity of the adjacent regenerative braking energy recovery devices is an optimally configured capacity; and, if not, the capacity of the adjacent regenerative braking energy recovery devices is increased by an integral time of the capacity unit value of the regenerative braking energy recovery devices, to obtain optimally configured capacity of the adjacent regenerative braking energy recovery devices. By using the optimally configured capacity of the adjacent regenerative braking energy recovery devices, the regenerative braking energy to be absorbed by the failed regenerative braking energy recovery device can be completely absorbed.

(36) With continued reference to FIG. 4, the step S22 comprises the following steps.

(37) S221: According to the S13, the preliminarily configured capacity P.sub.n, the departure interval x and the valid value of the maximum regenerative braking power P.sub.nx within different continuous periods of time T under the corresponding departure interval x of the failed regenerative braking energy recovery device is obtained, meanwhile, valid values of the maximum regenerative braking power of the adjacent regenerative braking energy recovery devices P.sub.(n−1)x and P.sub.(n+1)x within different continuous periods of time T under the corresponding departure interval x are obtained.

(38) S222: Whether Z.sub.n−1+Z.sub.n+1≥P.sub.(n−1)x+P.sub.nx+P.sub.(n+1)x is true is determined; if so, the actually configured capacity Z.sub.n−1 and Z.sub.n+1 of adjacent traction substations n−1 and n+1 remain unchanged; and, if not, perform S223;

(39) S223: The magnitude of the distances from the traction substation n respectively to the adjacent traction substation n−1 and to the adjacent traction substation n+1 L.sub.n(n−1) and L.sub.n(n+1) is determined; if L.sub.n(n−1)≥L.sub.n(n+1), the actually configured capacity Z.sub.1+1 of the traction substation n+1 is increased by an integral time of the capacity unit value of the regenerative braking energy recovery devices to obtain an optimally configured capacity Q.sub.n+1, and the optimally configured capacity Q.sub.n−1 of the traction substation n−1 is the actually configured capacity Z.sub.n−1; and, if L.sub.n(n−1)≤L.sub.n(n+1), the actually configured capacity Z.sub.n−1 of the traction substation n−1 is increased by an integral time of the capacity unit value of the regenerative braking energy recovery devices to obtain an optimally configured capacity Q.sub.n−1, and the optimally configured capacity Q.sub.n+1 of the traction substation n+1 is the actually configured capacity Z.sub.n+1. By using the optimally configured capacity Q.sub.n+1 or Q.sub.n−1 that is increased by an integral time of the capacity unit value, the regenerative braking energy to be absorbed by the failed regenerative braking energy recovery device can be completely absorbed.

(40) Preferably, the capacity of the adjacent regenerative braking energy recovery devices is increased by 0.5 MW to finely adjust the converted capacity. If the capacity is too high, the capacity of the devices will be idle and wasted.

(41) To describe the step S22 more clearly, the step S221 to S223 are expressed in another way, specifically:

(42) S221: According to the preliminarily configured capacity P.sub.n−1 and P.sub.n+1 of the adjacent regenerative braking energy recovery devices of the failed regenerative braking energy recovery device obtained in the step S13, the actually configured capacity Z.sub.n−1 and Z.sub.n+1 of the two are converted according to the method in S21;

(43) S222: Whether Z.sub.n−1+Z.sub.n+1≥P.sub.n−1+P.sub.n+P.sub.n+1 is true is determined; if so, the actually configured capacity Z.sub.n−1 and Z.sub.1+1 of adjacent traction substations n−1 and n+1 remains unchanged; and, if not, perform S223;

(44) S223: The magnitude of the distances from the traction substation n respectively to the adjacent traction substation n−1 and to the adjacent traction substation n+1 L.sub.n(n−1) and L.sub.n(n+1) is determined; if L.sub.n(n−1)≥L.sub.n(n+1), the actually configured capacity Z.sub.n+1 of the traction substation n+1 is increased by an integral time of the capacity unit value of the regenerative braking energy recovery devices to obtain an optimally configured capacity Q.sub.n+1, and the optimally configured capacity Q.sub.n−1 of the traction substation n−1 is the actually configured capacity Z.sub.n−1; and, if L.sub.n(n−1)≤L.sub.n(n+1), the actually configured capacity Z.sub.n−1 of the traction substation n−1 is increased by an integral time of the capacity unit value of the regenerative braking energy recovery devices to obtain an optimally configured capacity Q.sub.n−1, and the optimally configured capacity Q.sub.n+1 of the traction substation n+1 is the actually configured capacity Z.sub.n+1. By using the optimally configured capacity Q.sub.n+1 or Q.sub.n−1 that is increased by an integral time of the capacity unit value, the regenerative braking energy to be absorbed by the failed regenerative braking energy recovery device can be completely absorbed.

(45) Through the above steps S221 to S223, the n of the traction substation has a value from 1 to N, and the optimally configured capacity Q.sub.1 to Q.sub.N of the regenerative braking energy recovery devices in the traction substations can be calculated.

(46) Preferably, the capacity of the adjacent regenerative braking energy recovery devices is increased by 0.5 MW to finely adjust the converted capacity. If the capacity is too high, the capacity of the device will be idle and wasted.

(47) During the optimally configuring of the capacity of the regenerative energy recovery devices, considering the sudden failure of the regenerative braking energy recovery device during the actual operation, the capability of adjacent regenerative braking energy recovery devices to share the power of the failed regenerative braking energy recovery device is calculated, the adjacent regenerative braking energy recovery devices with insufficient sharing capability are appropriately increased in capacity. In the adjacent regenerative braking energy recovery devices, the regenerative braking energy recovery device closest to the failed regenerative braking energy recovery device is selected and increased in capacity, so that the highest capability to share the power of the failed device is ensured. Meanwhile, the capacity is increased by 0.5 MW, so that the actual engineering experience and cost are fully taken into consideration and the better regenerative braking energy recovery effect is achieved.

(48) As shown in FIG. 5, the step S3 comprises the following steps.

(49) S31: Whether the optimally configured capacity Q of the regenerative braking energy recovery device corresponding to the traction substation n is less than two times of the capacity unit value of the regenerative braking energy recovery devices (i.e., preferably 1 MW) is determined; if so, the regenerative braking energy recovery device is removed from the traction substation n; and, if not, the regenerative braking energy recovery device is installed in the traction substation n according to the optimally configured capacity Q.sub.n.

(50) The step S31 may be adjusted as required. For example, to further improve the recovered regenerative braking energy, whether the optimally configured capacity Q.sub.n of the regenerative braking energy recovery device corresponding to the traction substation n is less than the capacity unit value of the regenerative braking energy recovery devices (i.e., 0.5 MW) is determined; if so, the regenerative braking energy recovery device is removed from the traction substation n; and, if not, the regenerative braking energy recovery device is installed in the traction substation n according to the optimally configured capacity Q.sub.n.

(51) S32: The actual total number M of the regenerative braking energy recovery devices installed and the actual total configured capacity

(52) $\underset{n=1}{\overset{N}{.Math.}}{Q}_n$
of the regenerative braking energy recovery devices are obtained according to the result determined in the S31, wherein, according to the S31, an optimally configured capacity that is less than two times of the capacity unit value of the regenerative braking energy recovery devices or an optimally configured capacity that is one time of the capacity unit value of the regenerative braking energy recovery devices is not included in Q.sub.n.

(53) With reference to FIG. 5, the step S4 comprises the following steps.

(54) S41: An average capacity

(55) $E=\underset{n=1}{\overset{N}{.Math.}}{Q}_n/M$
of the regenerative braking energy recovery devices is calculated according to the result of calculation in the S32.

(56) S42: Whether the traction substation n is adjacent to a main substation is determined; if so, the regenerative braking energy recovery device corresponding to the traction substation n is configured as an energy storage unit; and, if not, perform S43.

(57) S43: Whether the optimally configured capacity Q.sub.n of the regenerative braking energy recovery device corresponding to the traction substation n is less than the average capacity E is determined; if so, the regenerative braking energy recovery device of the traction substation n is configured as an energy storage unit; and, if not, the regenerative braking energy recovery device of the traction substation n is configured as an energy feedback unit.

(58) By reasonably configuring the type of regenerative braking energy recovery devices, the deficiency of a single regenerative braking energy recovery device can be avoided.

(59) With reference to FIG. 6, an embodiment of the present application provides a system for configuring regenerative braking energy recovery devices in urban rail transit. The system uses the configuration method described above.

(60) The system comprises a preliminary configurating unit, a capacity optimally configuring unit, a total number configurating unit and a type configurating unit; the preliminary configurating unit comprises a traction simulation and calculation module configured to perform traction simulation and calculation, and a train power supply simulation and calculation module configured to perform train power supply simulation and calculation;

(61) the preliminary configurating unit is configured to perform train traction simulation and calculation, further to perform train power supply simulation and calculation according to the result of the train traction simulation and calculation to obtain a regenerative braking power S.sub.n(t) of a traction substation n, and calculate a preliminarily configured capacity P.sub.n of regenerative braking energy recovery device predetermined for the traction substation n according to the regenerative braking power S.sub.n(t) of the traction substation n, where n∈{1, 2, 3, . . . X} and N is the total number of traction substations; the capacity optimally configuring unit is configured to perform capacity optimal configuration for the regenerative braking energy recovery devices to obtain an optimally configured capacity Q.sub.n of the regenerative braking energy recovery devices corresponding to the traction substation n, according to the preliminarily configured capacity P.sub.n of regenerative braking energy recovery devices and in combination with the specification of the existing regenerative braking energy recovery devices and by considering that when a regenerative braking energy recovery device is failed, adjacent regenerative braking energy recovery devices are capable to completely absorb the regenerative braking energy to be absorbed by the failed regenerative braking energy recovery device;

(62) the total number configurating unit is configured to perform configuration for the total number M of the regenerative braking energy recovery devices installed according to the optimally configured capacity Q.sub.n of the regenerative braking energy recovery devices;

(63) the type configurating unit is configured to further perform configuration for the type of the regenerative braking energy recovery devices of the traction substation n, according to the optimally configured capacity Q.sub.n and the total number M of the regenerative braking energy recovery devices installed as well as the locations of the regenerative braking energy recovery devices.