CLOSED-LOOP CONTROL DEVICE FOR CLOSED-LOOP CONTROL OF A POWER ASSEMBLY INCLUDING AN INTERNAL COMBUSTION ENGINE AND A GENERATOR HAVING AN OPERATIVE DRIVE CONNECTION TO THE INTERNAL COMBUSTION ENGINE, CLOSED-LOOP CONTROL ARRANGEMENT HAVING SUCH A CLOSED-LOOP CONTROL DEVICE, POWER ASSEMBLY AND METHOD FOR CLOSED-LOOP CONTROL OF A POWER ASSEMBLY

Abstract

A closed-loop control device includes: a power controller for: detecting a generator power of a generator as a controlled variable, determining a power control deviation as a difference between the detected generator power and a target generator power; and determining a first preset variable as a function of the power control deviation; a frequency controller for: detecting a generator frequency of the generator as a controlled variable, determining a frequency control deviation as a difference between the detected generator frequency and a target generator frequency; determining a second preset variable as a function of the frequency control deviation; and a preselection module for determining a third preset variable, the closed-loop control device for: combining the first preset variable, the second preset variable, and the third preset variable with one another to form an overall preset variable; and using the overall preset variable for controlling an internal combustion engine.

Claims

1. A closed-loop control device for closed-loop control of a power assembly including an internal combustion engine and a generator having an operative drive connection to the internal combustion engine, the closed-loop control device comprising: a power controller which is configured for: detecting a generator power (P.sub.G) of the generator as a controlled variable; determining a power control deviation (e.sub.P) as a difference between the generator power (P.sub.G) which is detected and a target generator power (P.sub.soll); and determining a first preset variable as a function of the power control deviation (e.sub.P); a frequency controller which is configured for: detecting a generator frequency (f.sub.G) of the generator as a controlled variable; determining a frequency control deviation (e.sub.f) as a difference between the generator frequency (f.sub.G) which is detected and a target generator frequency (f.sub.soll); determining a second preset variable as a function of the frequency control deviation (e.sub.f); and a preselection module which is configured for determining a third preset variable; the closed-loop control device being configured for: combining the first preset variable, the second preset variable, and the third preset variable with one another to form an overall preset variable; and using the overall preset variable for controlling the internal combustion engine.

2. The closed-loop control device according to claim 1, wherein the closed-loop control device is configured for adding the first preset variable, the second preset variable, and the third preset variable to one another to form the overall preset variable.

3. The closed-loop control device according to claim 1, wherein the preselection module is configured for determining the third preset variable based on a target generator power variable (P.sub.soll.sup.g).

4. The closed-loop control device according to claim 1, wherein the preselection module is configured for determining the third preset variable based on a target generator power variable (P.sub.soll.sup.g) and the generator frequency (f.sub.G) which is detected.

5. The closed-loop control device according to claim 1, wherein the closed-loop control device is configured for determining a target torque in each case as the first preset variable, as the second preset variable, and as the third preset variable.

6. The closed-loop control device according to claim 1, wherein the power controller is configured for determining a power target torque (M.sub.soll.sup.P) as a function of the power control deviation (e.sub.P) as the first preset variable, wherein the frequency controller is configured for determining a frequency target torque (M.sub.soll.sup.f) as a function of the frequency control deviation (e.sub.f) as the second preset variable, wherein the preselection module is configured for determining a preselection target torque (M.sub.soll.sup.Vor) as the third preset variable, and wherein the closed-loop control device is configured for combining the power target torque (M.sub.soll.sup.P), the frequency target torque (M.sub.soll.sup.f), and the preselection target torque (M.sub.soll.sup.Vor) with one another to form an overall target torque (M.sub.soll) as the overall preset variable.

7. The closed-loop control device according to claim 1, wherein the preselection module is configured for calculating the third preset variable by dividing a target generator power variable (P.sub.soll.sup.g) by the generator frequency (f.sub.G) which is detected, and wherein a quotient thus obtained is multiplied by a predetermined constant pre-factor (F).

8. The closed-loop control device according to claim 1, wherein the closed-loop control device is formed as: an open-loop control device configured for directly controlling the internal combustion engine; or a generator controller.

9. The closed-loop control device according to claim 8, wherein the closed-loop control device is formed as a generator controller with an interface to an open-loop control device of the internal combustion engine.

10. The closed-loop control device according to claim 1, wherein the power controller is configured for: calculating a first preset variable additional term from the target generator power (P.sub.soll) by way of a first calculation element, which has a differential transmission behavior; and offsetting the first preset variable additional term with a first precursor preset variable calculated by the power controller in order to obtain the first preset variable.

11. The closed-loop control device according to claim 1, wherein the power controller is configured for: calculating a first preset variable additional term from the target generator power (P.sub.soll) by way of a first calculation element, which has a differential transmission behavior; and offsetting the first preset variable additional term with a first precursor preset variable calculated by the power controllerin order to add the first preset variable additional term to the first precursor preset variablein order to obtain the first preset variable.

12. The closed-loop control device according to claim 1, wherein the preselection module is configured for: calculating a second precursor preset variable from a target generator power variable (P.sub.soll.sup.g) and the generator frequency (f.sub.G) which is detected; and calculating the third preset variable from a second precursor preset variable by way of a second calculation element, which has a proportional and differential transmission behavior.

13. The closed-loop control device according to claim 1, wherein the preselection module is configured for calculating a target generator power variable (P.sub.soll.sup.g) from the target generator power (P.sub.soll) by way of a third calculation element, which has a proportional and differential transmission behavior.

14. A closed-loop control arrangement for closed-loop control of a power assembly including an internal combustion engine and a generator having an operative drive connection to the internal combustion engine, the closed-loop control arrangement comprising: a closed-loop control device which is formed as a generator controller, is for closed-loop control of the power assembly, and includes: a power controller which is configured for: detecting a generator power (P.sub.G) of the generator as a controlled variable; determining a power control deviation (e.sub.P) as a difference between the generator power (P.sub.G) which is detected and a target generator power (P.sub.soll); and determining a first preset variable as a function of the power control deviation (e.sub.P); a frequency controller which is configured for: detecting a generator frequency (f.sub.G) of the generator as a controlled variable; determining a frequency control deviation (e.sub.f) as a difference between the generator frequency (f.sub.G) which is detected and a target generator frequency (f.sub.soll); determining a second preset variable as a function of the frequency control deviation (e.sub.f); and a preselection module which is configured for determining a third preset variable; the closed-loop control device being configured for: combining the first preset variable, the second preset variable, and the third preset variable with one another to form an overall preset variable; and using the overall preset variable for controlling the internal combustion engine; and an open-loop control device operatively connected to the closed-loop control device for direct control of the internal combustion engine, the closed-loop control device being configured for transmitting the overall preset variable to the open-loop control device.

15. A power assembly, comprising: an internal combustion engine; a generator including an operative drive connection to the internal combustion engine; and one of: (a) a closed-loop control device for closed-loop control of the power assembly, the closed-loop control device including: a power controller which is configured for: detecting a generator power (P.sub.G) of the generator as a controlled variable; determining a power control deviation (e.sub.P) as a difference between the generator power (P.sub.G) which is detected and a target generator power (P.sub.soll); and determining a first preset variable as a function of the power control deviation (e.sub.P); a frequency controller which is configured for: detecting a generator frequency (f.sub.G) of the generator as a controlled variable; determining a frequency control deviation (e.sub.f) as a difference between the generator frequency (f.sub.G) which is detected and a target generator frequency (f.sub.soll); determining a second preset variable as a function of the frequency control deviation (e.sub.f); and a preselection module which is configured for determining a third preset variable; the closed-loop control device being configured for: combining the first preset variable, the second preset variable, and the third preset variable with one another to form an overall preset variable; and using the overall preset variable for controlling the internal combustion engine; and (b) a closed-loop control arrangement for closed-loop control of the power assembly, the closed-loop control arrangement including: a closed-loop control device which is formed as a generator controller, is for closed-loop control of the power assembly, and includes: a power controller which is configured for: detecting a generator power (P.sub.G) of the generator as a controlled variable; determining a power control deviation (e.sub.P) as a difference between the generator power (P.sub.G) which is detected and a target generator power (P so ra); and determining a first preset variable as a function of the power control deviation (e.sub.P); a frequency controller which is configured for: detecting a generator frequency (f.sub.G) of the generator as a controlled variable; determining a frequency control deviation (e.sub.f) as a difference between the generator frequency (f.sub.G) which is detected and a target generator frequency (f.sub.soll); determining a second preset variable as a function of the frequency control deviation (e.sub.f); and a preselection module which is configured for determining a third preset variable; the closed-loop control device being configured for: combining the first preset variable, the second preset variable, and the third preset variable with one another to form an overall preset variable; and using the overall preset variable for controlling the internal combustion engine; and an open-loop control device operatively connected to the closed-loop control device for direct control of the internal combustion engine, the closed-loop control device being configured for transmitting the overall preset variable to the open-loop control device; wherein the closed-loop control device or the closed-loop control arrangement is operatively connected to the internal combustion engine and the generator of the power assembly.

16. A method for closed-loop control of a power assembly including an internal combustion engine and a generator having an operative drive connection to the internal combustion engine, the method comprising the steps of: detecting a generator power (P.sub.G) of the generator as a controlled variable; determining a power control deviation (e.sub.P) as a difference between the generator power (P.sub.G) which is detected and a target generator power (P.sub.soll); determining a first preset variable as a function of the power control deviation (e.sub.P); detecting a generator frequency (f.sub.G) of the generator as a controlled variable; determining a frequency control deviation (e.sub.f) as a difference between the generator frequency (f.sub.G) which is detected and a target generator frequency (f.sub.soll); determining a second preset variable as a function of the frequency control deviation (e.sub.f); determining a third preset variable; offsetting the first preset variable, the second preset variable, and the third preset variable with one another to form an overall preset variable; and using the overall preset variable for controlling the internal combustion engine.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0060] The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein:

[0061] FIG. 1 shows a schematic representation of a first exemplary embodiment of a power assembly with a first exemplary embodiment of a closed-loop control arrangement and a first exemplary embodiment of a closed-loop control device;

[0062] FIG. 2 shows a schematic representation of a second exemplary embodiment of a power assembly with a second exemplary embodiment of a closed-loop control device;

[0063] FIG. 3 shows a schematic detailed representation of the first exemplary embodiment of the power assembly;

[0064] FIG. 4 shows a schematic detailed representation of the second exemplary embodiment of the power assembly;

[0065] FIG. 5 shows a schematic detailed representation of the closed-loop control device;

[0066] FIG. 6 shows a schematic detailed representation of a third exemplary embodiment of a power assembly with a third exemplary embodiment of a closed-loop control device;

[0067] FIG. 7 shows a schematic representation of a fourth exemplary embodiment of a power assembly with a fourth exemplary embodiment of a closed-loop control device;

[0068] FIG. 8 shows a schematic representation of a fifth exemplary embodiment of a power assembly with a fifth exemplary embodiment of a closed-loop control device; and

[0069] FIG. 9 shows a schematic, diagrammatic representation of the mode of operation of a method for closed-loop control of a power assembly.

[0070] Corresponding reference characters indicate corresponding parts throughout the several views. The exemplification set out herein illustrate embodiments of the invention, and such exemplifications are not to be construed as limiting the scope of the invention in any manner

DETAILED DESCRIPTION OF THE INVENTION

[0071] FIG. 1 shows a schematic representation of a first exemplary embodiment of a power assembly 1 with a first exemplary embodiment of a closed-loop control arrangement 13 and a first exemplary embodiment of a closed-loop control device 3. The power assembly 1 in this exemplary embodiment is part of a higher-level network of a multiplicity of power assemblies, of which only the one power assembly 1 considered in greater detail here is shown. In particular, the power assembly 1 is electrically connected to a power grid 4, here specifically to a busbar 6. In particular, the power assembly 1 can be operated in island parallel operation or in grid parallel operation; in particular, the power grid 4 can be a local power grid, in particular an on-board electrical system of a vehicle, for example a ship, or a supra-regional power grid. An external open-loop control unit 8 is assigned to the power grid 4 and distributes a total power P.sub.Schiene requested at the busbar 6, which is also referred to as the total load, across the individual power assemblies 1, in particular by calculating a separate target generator power P.sub.soll.sup.1, P.sub.soll.sup.2, P.sub.soll.sup.3, etc. for each power assembly 1. A first target generator power P.sub.soll.sup.1 assigned to the power assembly 1 specifically shown here is referred to in the following as the target generator power P.sub.soll for short for the sake of simplicity.

[0072] However, the power assembly 1 can also be operated in isolation.

[0073] It is also possible that the power distribution is not carried out in an external open-loop control unit 8, but in the closed-loop control device 3 itself, in particular in a master closed-loop control device of one of the power assemblies 1, wherein the other closed-loop control devices 3 of the other power assemblies 1 are then optionally operated as slave closed-loop control devices, which receive their respective target generator power from the master closed-loop control device.

[0074] The power assembly 1 has an internal combustion engine 5 and a generator 9 which has an operative drive connection to the internal combustion engine 5 via a shaft 7 shown schematically. The closed-loop control device 3 is operatively connected to the internal combustion engine 5 on the one hand and to the generator 9 on the other. In particular, the generator 9 is electrically connected to the busbar 6 in a manner not presented explicitly here.

[0075] In particular, the closed-loop control device 3 is set upcompare also FIGS. 3 and 4 in this regardfor closed-loop control of the power assembly 1, wherein it has a power controller 14 which is set up to detect a generator power P.sub.G of the generator 9 as a first controlled variable, to determine a power control deviation e.sub.P as the difference between the detected generator power P.sub.G and the target generator power P.sub.soll, and to determine a first preset variable 16 as a manipulated variable for controlling the internal combustion engine 5 as a function of the power control deviation e.sub.P. In addition, the closed-loop control device 3 has a frequency controller 18, which is set up to detect a generator frequency f.sub.G of the generator 9 as a second controlled variable, to determine a frequency control deviation of as the difference between the detected generator frequency f.sub.G and the target generator frequency f.sub.soll, and to determine a second preset variable as a manipulated variable for controlling the internal combustion engine 5 as a function of the frequency control deviation e.sub.f. The closed-loop control device 3 additionally has a preselection module 22, which is set up to determine a third preset variable 24 in particular as a preselection variable for controlling the internal combustion engine 5. The closed-loop control device 3 is set up to combine, in particular to offset, the first preset variable 16, the second preset variable 20, and the third preset variable 24 with one another to form an overall preset variable 26, and to use, in particular to output, the overall preset variable 26 as a manipulated variable for controlling the internal combustion engine 5. In particular, the first preset variable 16, the second preset variable 20, and the third preset variable 24 are added to one another, by which the overall preset variable 26 is obtained.

[0076] The closed-loop control device 3 enables a dynamic load switching behavior and at the same time a robust closed-loop control of both the generator frequency and the generator power. The dynamics are provided here by the preselection module 22, while the first preset variable 16 and the second preset variable 20 are added correctively to ensure a stable closed-loop control.

[0077] The overall preset variable 26 in the first exemplary embodiment described here is in particular a target torque M.sub.soll, which is also designated as the overall target torque. Accordingly, each of the first, second, and third preset variables 16, 20, and 24 is optionally also a torque.

[0078] The closed-loop control device 3 is designed as a generator controller 12 according to the first exemplary embodiment shown here and is operatively connected to an open-loop control device 11 of the internal combustion engine 5 in such a way that the overall preset variable 26 can be transmitted from the closed-loop control device 3 to the open-loop control device 11. This also enables, at the same time, particularly robust closed-loop control and versatile usability of the closed-loop control device 3, in particular with a multiplicity of power assemblies 1.

[0079] The closed-loop control device 3 and the open-loop control device 11 together form the closed-loop control arrangement 13 for control of the power assembly 1. The open-loop control device 11 is optionally designed as an engine controller 15, in particular as an engine control unit (ECU).

[0080] From the target torque M.sub.soll, the open-loop control device 11optionally as a function of further engine variables, in particular a detected speed n.sub.istcalculates an energization duration BD for controlling fuel injection valves of the internal combustion engine 5.

[0081] A speed controller of the open-loop control device 11 is optionally deactivated. Optionally, a final idling speed controller of the open-loop control device 11 is activated. This is used to control the speed of the internal combustion engine 5 if the detected speed n.sub.ist falls below a lower speed limit n.sub.Leer or exceeds an upper speed limit n.sub.End. Between these speed limits, a target torque calculated in the open-loop control device 11 is equal to the target torque M.sub.soll specified by the closed-loop control device 3. In particular, a torque specification is activated in the open-loop control device 11.

[0082] FIG. 2 shows a schematic representation of a second exemplary embodiment of a power assembly 1 with a second exemplary embodiment of a closed-loop control device 3.

[0083] Like and functionally similar elements are provided with the same reference signs in all figures, and therefore reference is made to the previous description in each case.

[0084] In this exemplary embodiment the closed-loop control device 3 itself is designed as an open-loop control device 11, in particular an engine controller 15, for direct, in particular immediate, control of the internal combustion engine 5. In particular, the closed-loop control device 3 is set up to calculate, by way of a calculation element 28, an energization duration BD for controlling the injectors of the internal combustion engine 5 from the overall preset variable 26 calculated internally by the closed-loop control device 3, in particular the target torque M.sub.soll.

[0085] FIG. 3 shows a schematic detailed representation of the first exemplary embodiment of the power assembly 1. The closed-loop control device 3 is optionally set up to filter an instantaneous actual power P.sub.ist of the generator 9 in a power filter 19 and to use the filtered actual power P.sub.ist as the detected generator power P.sub.G. According to an optional embodiment, the power filter 19 is a PT.sub.1 filter or a mean value filter.

[0086] The closed-loop control device 3 is additionally set up to filter an instantaneous actual frequency f.sub.ist of the generator 9 in a frequency filter 21 and to use the filtered actual frequency f.sub.ist as the detected generator frequency f.sub.G. According to an optional embodiment, the frequency filter 21 is a PT.sub.1 filter or a mean value filter. In an optional embodiment, the frequency filter 21 is also set up to limit the instantaneous actual frequency f.sub.ist or the filtered actual frequency f.sub.ist in particular to a predetermined minimum frequency as the lower limit. However, the limiting of the generator frequency can also take place at another point in the closed-loop control device 3. In particular, it is possible that corresponding limiting is only carried out for the preselection module 22 or in the preselection module 22.

[0087] The preselection module 22 is set up in particular to calculate the third preset variable 24 on the basis of equation (1) (here with P.sub.soll.sup.g=P.sub.soll).

[0088] The closed-loop control device 3 is set up in particular to add the first preset variable 16, the second preset variable 20, and the third preset variable 24 to form the overall preset variable 26.

[0089] In the exemplary embodiment shown here, the closed-loop control device 3 is designed as a higher-level generator controller 12. The open-loop control device 11 designed as the engine controller 15 is set up to determine, in particular to calculate, a maximum target torque M.sub.soll.sup.max, in particular as a function of at least one engine variable of the internal combustion engine 5, in particular of its instantaneous speed and the instantaneous charge air pressure, and to transmit the maximum target torque M.sub.soll.sup.max to the closed-loop control device 3. The closed-loop control device 3 is set up in particular to receive the maximum target torque M.sub.soll.sup.max from the open-loop control device 11. The power controller 14 is set up to limit the first preset variable 16 and optionally its integral component to the maximum target torque M.sub.soll.sup.max. The frequency controller 18 is optionally set up to limit the second preset variable 20, optionally its integral component, to the maximum target torque M.sub.soll.sup.max.

[0090] The closed-loop control device 3 is set up in particular to determine a target torque in each case as the first preset variable 16, the second preset variable 20, and the third preset variable 24.

[0091] In particular, the power controller 14 is set up to determine a power target torque M.sub.soll.sup.P as the first preset variable 16 as a function of the power control deviation e.sub.P. The frequency controller 18 is set up to determine a frequency target torque M.sub.soll.sup.f as the second preset variable 20 as a function of the frequency control deviation e.sub.f. The preselection module 22 is set up to determine the preselection target torque M.sub.soll.sup.Vor as the third preset variable 24. The closed-loop control device 3 is set up to combine, in particular to add, the power target torque M.sub.soll.sup.P, the frequency target torque M.sub.soll.sup.f, and the preselection target torque M.sub.soll.sup.Vor with one another to form the overall target torque M.sub.soll as the overall preset variable 26.

[0092] FIG. 4 shows a schematic detailed representation of the second exemplary embodiment of the power assembly 1. The mode of operation of the closed-loop control device 3 designed as the engine controller 15 in this exemplary embodiment is the same as the mode of operation of the closed-loop control device 3 explained in conjunction with FIG. 3, wherein the energization duration BD is calculated directly in the closed-loop control device 3 from the target torque M.sub.soll, however, i.e., from the overall preset variable 26, by way of a calculation element 28. In addition, the maximum target torque M.sub.soll.sup.max is available directly in the closed-loop control device 3 or is calculated by this itself here.

[0093] FIG. 5 shows a schematic detailed representation of the closed-loop control device 3. In particular the mode of operation of the power controller 14, the frequency controller 18, and the preselection module 22 are shown here.

[0094] The mode of operation is represented in a time-discrete representation, wherein the sampling steps are designated by a running index. The index value of the running index indicated by k corresponds to an instantaneous sampling step. Accordingly, the index value indicated by k?1 denotes the sampling step immediately before the sampling step denoted by k.

[0095] The control algorithms for the power controller 14 and the frequency controller 18 are designed as PI controllers. Alternatively, however, it is also possible that at least one of the controllers, selected from the power controller 14 and the frequency controller 18, is designed as a PID controller or as a PI(DT.sub.1) controller.

[0096] The power controller 14 calculates the power control deviation e.sub.P(k) from the target generator power P.sub.soll(k) and the detected generator power P.sub.G(k) in the current sampling step k, and, from this, a power proportional component M.sub.soll.sup.P,p(k), by multiplying the power control deviation e.sub.P(k) by a first power constant r.sub.1.sup.P. The first power constant r.sub.1.sup.P is optionally equal to an optionally parameterizable, i.e., predeterminable power proportional coefficient k.sub.p.sup.P. The power controller 14 also calculates a power integral component M.sub.soll.sup.P,i(k) using the trapezoidal rule for integration by adding the power control deviation e.sub.P(k) of the current sampling step k to the power control deviation e.sub.P(k?1) of the previous sampling step k?1, wherein the sum thus formed is multiplied by a second power constant r.sub.2.sup.P, wherein the product thus formed is added to the preceding power integral component M.sub.soll.sup.P,i(k?1) delayed by one sampling step t.sub.a, and wherein the sum in turn formed in this way is delimited upward to the maximum target torque M.sub.soll.sup.max. The power integral component M.sub.soll.sup.P,i(k) thus calculated is added to the power proportional component M.sub.soll.sup.P,p(k), wherein the sum formed in this way is again delimited upward to the maximum target torque M.sub.soll.sup.max. This results in the first preset variable 16, in this case the target torque M.sub.soll.sup.P(k) of the power controller 14.

[0097] The second power constant r.sub.2.sup.p is optionally given by:

[00003] $\begin{matrix} r_{2}^{P} = \frac{k_{p}^{P} ?_{a}}{2 ?_{N}}, & (6) \end{matrix}$

with the parameterizable power proportional coefficient k.sub.p.sup.P, the time width ?.sub.a of a sampling step, and the parameterizable reset time ?.sub.N.

[0098] The frequency controller 18 calculates the frequency control deviation e.sub.f(k) from the target generator frequency f.sub.soll(k) and the detected generator frequency f.sub.G(k) in the current sampling step k, and, from this, a frequency proportional component M.sub.soll.sup.f,p(k), by multiplying the frequency control deviation e.sub.f(k) by a first frequency constant r.sub.1.sup.f. The first frequency constant r.sub.i.sup.f is optionally equal to an optionally parameterizable, i.e., predeterminable frequency proportional coefficient k.sub.p.sup.f. The frequency controller 18 also calculates a frequency integral component M.sub.soll.sup.f,i(k), using the trapezoidal rule for integration by adding the frequency control deviation e.sub.f(k) of the current sampling step k to the frequency control deviation e.sub.f(k?1) of the previous sampling step k?1, wherein the sum thus formed is multiplied by a second frequency constant r.sub.2.sup.f, wherein the product thus formed is added to the preceding frequency integral component M.sub.soll.sup.f,i(k?1) delayed by one sampling step t.sub.a, and wherein the sum in turn formed in this way is delimited upward to the maximum target torque M.sub.soll.sup.max. The frequency controller 18 adds the frequency integral component M.sub.soll.sup.f,i(k) thus calculated to the frequency proportional component M.sub.soll.sup.f,p(k), and again delimits the sum formed in this way upward to the maximum target torque M.sub.soll.sup.max. This then results in the second preset variable 20, in this case the target torque M.sub.soll.sup.f(k) of the frequency controller 18.

[0099] The second frequency constant r.sub.2.sup.f is optionally given by:

[00004] $\begin{matrix} r_{2}^{f} = \frac{k_{p}^{f} ?_{a}}{2 ?_{N}}, & (7) \end{matrix}$

with the parameterizable frequency proportional coefficient k.sub.p.sup.f, the time width ?.sub.a of a sampling step, and the parameterizable reset time ?.sub.N.

[0100] The preselection module 22 is optionally set up to limit the detected generator frequency f.sub.G(k) to a predetermined minimum frequency f.sub.min by way of a limiting element 30, wherein the limiting element 30 selects and passes on as the limited detected generator frequency f.sub.G,b(k) in particular the maximum of the detected generator frequency f.sub.G(k) and the predetermined minimum frequency f.sub.min. The reciprocal of the limited detected generator frequency f.sub.G,b(k) is then calculated in a reciprocal element 32 and this reciprocal is multiplied in a first multiplication element 34 by a target generator power variable f.sub.G,b(k), in the exemplary embodiment shown here by the target generator power P.sub.soll(k). The product thus calculated is then multiplied in a second multiplication element 36 by the predetermined constant pre-factor F, from which the third preset variable 24 results as the preselection target torque M.sub.soll.sup.Vor(k). The third preset variable 24 is thus calculated essentially according to equation (1), wherein in an optional embodiment the limited detected generator frequency f.sub.G,b(k) is used as the detected generator frequency f.sub.G(k). It is also possible, however, that the detected generator frequency f.sub.G(k) is used directly. It is also possible that the limiting of the generator frequency does not take place in the preselection module 22, wherein then the preselection module 22 receives the limited detected generator frequency f.sub.G,b(k) as the input variable.

[0101] The preselection module 22 is thus set up in particular to determine the third preset variable 24 on the basis of the target generator power variable p.sub.soll.sup.g(k) and the detected generator frequency f.sub.G(k).

[0102] The preselection module 22 is set up in particular to calculate the third preset variable 24 by dividing the target generator power variable P.sub.soll.sup.g(k) by the detected generator frequency f.sub.G(k), wherein the quotient thus obtained is multiplied by the predetermined constant pre-factor F.

[0103] The closed-loop control device 3 is furthermore set up to combine, in particular to add, the first preset variable 16, the second preset variable 20, and the third preset variable 24 to form the overall preset variable 26, i.e., to combine, in particular to add, the power target torque M.sub.soll.sup.P(k), the frequency target torque M.sub.soll.sup.f(k), and the preselection target torque M.sub.soll.sup.Vor(k) to form the overall target torque M.sub.soll(k).

[0104] FIG. 6 shows a schematic detailed representation of a third exemplary embodiment of the power assembly 1 with a third exemplary embodiment of a closed-loop control device 3.

[0105] In each of the exemplary embodiments of FIGS. 6, 7, and 8, the closed-loop control device 3 is designed as an open-loop control device 11, in particular as an engine controller 15. However, the embodiments of the closed-loop control device 3 shown in these figures can also be implemented just as well in an exemplary embodiment of the closed-loop control device 3 which is designed as a higher-order generator controller 12. The technical teaching of FIGS. 6, 7, and 8 is therefore not restricted to the specific embodiment of the closed-loop control device 3 as the open-loop control device 11 or engine controller 15.

[0106] In the third exemplary embodiment of the close-loop control device 3 according to FIG. 6, the power controller 14 is set up to calculate a first preset variable additional term 40, in particular a dynamic power torque M.sub.soll.sup.P,dyn, from the target generator power P.sub.soll by way of a first calculation element 38 which has a differential transmission behavior, and to offset the first preset variable additional term 40 with a first precursor preset variable 42, in particular a static power target torque M.sub.soll.sup.P,stat, calculated by the power controller 14, in order to obtain the first preset variable 16, in particular the power target torque M.sub.soll.sup.P.

[0107] In particular, the closed-loop control device 3 is set up to add the first preset variable additional term 40 to the precursor preset variable 42 in order to obtain the first preset variable 16. In the exemplary embodiment shown here, the first calculation element 38 is a DT.sub.1 element. Alternatively, however, it is also possible for the first calculation element 38 to be designed as a D-element in another exemplary embodiment.

[0108] The target power P.sub.soll is thus amplified by the first calculation element 38 andin the exemplary embodiment shown heresuperimposed additively on the precursor preset variable 42. In this way, the closed-loop control device 3 has an improved, in particular more dynamic load switching behavior.

[0109] The embodiment shown here has the advantage over an embodiment in which the power controller 14 would have an overall PI(DT.sub.1) characteristic that only the target power P.sub.soll is amplified and not the power control deviation e.sub.P. If instead a power controller 14 were used that has an overall PI(DT.sub.1) characteristic, the dynamics of the power control would depend on the design of the power filter 19. If, for example, a PT.sub.1 power filter with a small time constant T.sub.1 were selected, this, in combination with the PI(DT.sub.1) characteristic of the power controller 14, would lead to a delayed adaptation to a sudden change in the target generator power P.sub.soll. Specifically, the detected generator power P.sub.G is subtracted from this, and then also changes rapidly when the load changes, in particular fed from the reserve of kinetic energy, in particular rotational energy, of the system consisting of the generator 9, the coupling 7 and the internal combustion engine 5. In particular, the actual generator power P.sub.ist follows an electrical load change almost instantaneously. This means that the target generator power P.sub.soll and the detected generator power P.sub.G change in the same effective direction, so that the power change is only attenuated in the power control deviation e.sub.P. The resulting delay is advantageously avoided ifas shown in FIG. 6the target generator power P.sub.soll is fed directly to the first calculation element 38.

[0110] The first calculation element 38 optionally has the following transfer function:

[00005] $\begin{matrix} G_{D T_{1}} (s) = K_{1} \frac{T_{V} s}{1 + T_{1} s}, & (8) \end{matrix}$

with a factor K.sub.1, the lead time T.sub.V and the delay time T.sub.1. The first calculation element 38 is only effective transiently or dynamically, i.e., only in the event of a load change. The preset variable additional term 40 also changes abruptly in the event of a sudden load change and then finally decays to zero. In a steady state, the preset variable additional term 40 is zero. How quickly the preset variable additional term 40 decays depends on the delay time T.sub.1. The factor K.sub.1 is used in particular to convert the physical unit of the input variable, i.e., the target generator power P.sub.soll, into the physical unit of the output variable, i.e., of the preset variable additional term 40, in particular a torque.

[0111] FIG. 7 shows a schematic representation of a fourth exemplary embodiment of a power assembly 1 with a fourth exemplary embodiment of a closed-loop control device 3.

[0112] In this fourth exemplary embodiment of the closed-loop control device 3, the preselection module 22 is set up to calculate a second precursor preset variable 44, in particular a static preselection target torque M.sub.soll.sup.Vor,stat, from the target generator power variable P.sub.soll.sup.g, here the target generator power P.sub.soll, and the detected generator frequency f.sub.G, and to calculate the third preset variable 24, namely the preselection target torque M.sub.soll.sup.Vor as a dynamic preselection target torque M.sub.soll.sup.Vor,dyn, from the second precursor preset variable 44 by way of a second calculation element 46 which has a proportional and differential transmission behavior.

[0113] The second calculation element 46 is designed in the exemplary embodiment shown here as a (PD)T.sub.1 element, with the following transmission function:

[00006] $\begin{matrix} G_{(P D) T_{1}} (s) = \frac{1 + T_{V} s}{1 + T_{1} s}, & (9) \end{matrix}$

with the lead time T.sub.V and the delay time T.sub.1. In the stationary case for s=0, the dynamic preselection target torque M.sub.soll.sup.Vor,dyn is thus identical to the static preselection target torque M.sub.soll.sup.Vor,stat. In the dynamic case for s?0, the static preselection target torque M.sub.soll.sup.Vor,stat is amplified with the aid of a (PD)T.sub.1 characteristic which decays in a stationary manner with the delay time T.sub.1 to the amplification 1.

[0114] FIG. 8 shows a schematic representation of a fifth exemplary embodiment of a power assembly 1 with a fifth exemplary embodiment of a closed-loop control device 3.

[0115] In this exemplary embodiment, the preselection module 22 is set up to calculate the target generator power variable P.sub.soll.sup.g, in particular as a dynamic target generator power P.sub.soll.sup.dyn, from the target generator power P.sub.soll by way of a third calculation element 48, which has a proportional and differential transmission behavior.

[0116] The third calculation element 48 is designed in the exemplary embodiment shown here as a (PD)T.sub.1 element, with the transmission function according to equation (9): In the stationary case for s=0, the target generator variable P.sub.soll.sup.g is thus identical to the target generator power P.sub.soll. In the dynamic case for s?0, the target generator power P.sub.soll is amplified with the aid of a (PD)T.sub.1 characteristic which decays in a stationary manner with the delay time T.sub.1 to the amplification 1.

[0117] Changes of the target generator power P.sub.soll are advantageously amplified here with the aid of the third calculation element 48, and notas in the exemplary embodiment according to FIG. 7changes of the quotient of the target generator power P.sub.soll divided by the detected generator frequency f.sub.G. In this embodiment according to FIG. 7, the amplifying effect of the (PD)T.sub.1 element is either attenuated or amplified depending on the direction in which the detected generator frequency f.sub.G moves at the moment of the load switching. The amplifying effect of the (PD)T.sub.1 element is advantageously independent of the detected generator frequency f.sub.G, in contrast, in the exemplary embodiment according to FIG. 8.

[0118] FIG. 9 shows a schematic, diagrammatic representation of the mode of operation of a method for closed-loop control of a power assembly 1. In particular, six time diagrams are shown here.

[0119] A first time diagram at a) shows the time curve of the target generator power P.sub.soll as a solid curve and the time curve of the detected generator power P.sub.G as a dashed curve. At a first point in time t.sub.1, the target generator power P.sub.soll increases suddenly to a first power value P.sub.1 and is subsequently identical to this value. Thefiltereddetected generator power P.sub.G increases from the first point in time t.sub.1 and finally reaches the target generator power P.sub.soll at a third point in time t.sub.3.

[0120] A third time diagram at c) shows the time curve of the first preset variable 16, namely the power target torque M.sub.soll.sup.P, i.e., the output variable of the power controller 14. Under the assumption of a PI characteristic for the power controller 14, the power target torque M.sub.soll.sup.P suddenly increases at the first point in time t.sub.1 to a first power torque value M.sub.1, which corresponds to the proportional component of the power controller 14 at this point in time. As a result, the power target torque M.sub.soll.sup.P decays up to the third point in time t.sub.3 in a simplified mode of observation to the value 0 Nm, since at this point in time the power control deviation e.sub.p is also identical to 0 kW and the overall preset variable 26 results as a manipulated variable in large part from the preselection, so that the integral component of the power controller 14 is also approximately identical to 0 kW after the third point in time t.sub.3.

[0121] A fourth time diagram at d) shows the time curve of the frequency target torque M.sub.soll.sup.f in the form of a dashed first curve K1 for the case of a static preselection and in the form of a solid second curve K2 for the case of a dynamic preselection.

[0122] A fifth time diagram at e) shows the time curve of the static preselection target torque M.sub.soll.sup.Vor,stat as a solid curve and the time curve of the dynamic preselection target torque M.sub.soll.sup.Vor,dyn as a dashed curve. The static preselection target torque M.sub.soll.sup.Vor,stat jumps at the first point in time t.sub.1 to a second preselection torque value M.sub.2, which is calculated according to equation (1); in particular the following applies:

[00007] $\begin{matrix} M_{2} = \frac{1000}{?} \frac{P_{1}}{f_{G}} . & (10) \end{matrix}$

[0123] Thefiltereddetected generator frequency f.sub.G is assumed to be constant for the sake of simplicity, so that the static preselection target torque M.sub.soll.sup.Vor,stat therefore remains at the constant second preselection torque value M.sub.2. The dynamic preselection target torque M.sub.soll.sup.Vor,dyn jumps at the first point in time t.sub.1 to a third preselection torque value M.sub.3 and then decays until it settles at a second point in time t.sub.2 at the value of the static preselection target torque M.sub.soll.sup.Vor,stat. The third preselection target torque M.sub.3 and the decay time are dependent here on the lead time T.sub.V and the delay time T.sub.1.

[0124] A sixth time diagram at f) represents the time curve of the overall preset variable 26, i.e., the target torque M.sub.soll, namely once in the form of a solid fourth curve K4 without dynamic preselection, i.e., with static preselection, and once in the form of a dashed third curve K3 with dynamic preselection.

[0125] In the case of the static preselection, the overall preset variable 26 jumps at the first point in time t.sub.1 to a fourth preselection torque value M.sub.4, for which the following applies:

M.sub.4=M.sub.1+M2. (11)

[0126] The frequency target torque M.sub.soll.sup.f is still identical to 0 Nm at this point in time, since the detected generator frequency f.sub.G is still identical to the target generator frequency f.sub.soll. As a result, the overall preset variable 26 decays and has settled at a sixth point in time t.sub.6 to the second preselection torque value M.sub.2 of the static preselection target torque M.sub.soll.sup.Vor,stat. The settling process only ends when the generator frequency has also settled. For this reason, the overall preset variable 26 has settled at a later point in time than the power target torque M.sub.soll.sup.P.

[0127] If a dynamic preselection is used, the overall preset variable 26 thus jumps at the first point in time t.sub.1 to a fifth preselection torque value M.sub.5:

M.sub.5=M.sub.1+M.sub.3. (12)

[0128] As a result, the overall preset variable 26 decays and has settled at a seventh point in time t.sub.7 to the second preselection torque value M.sub.2 of the static preselection target torque M.sub.soll.sup.Vor,stat.

[0129] A second time diagram at b) shows the time curve of the instantaneous actual generator frequency f.sub.ist as a dashed curve for the case of the static preselection and as a solid curve for the case of the dynamic preselection. In addition, the target generator frequency f.sub.soll, which is assumed to be constant for the purpose of simplification, is also shown as a dot-dash horizontal line.

[0130] In the case of the dynamic preselection, the actual generator frequency f.sub.ist only collapses to a first frequency f.sub.1, i.e., only by a first difference value Df.sub.1. The actual generator frequency f.sub.ist has in this case already settled at the sixth point in time t.sub.6 at the target generator frequency f.sub.soll.

[0131] In contrast, in the case of the static preselection, the actual generator frequency f.sub.ist collapses to a second, lower frequency value f.sub.2, i.e., by a second, greater difference value Df.sub.2, and has only settled at the seventh point in time t.sub.7 at the target generator frequency f.sub.soll.

[0132] The second time diagram thus shows that the use of a dynamic preselection results in a reduction of the frequency collapse of the generator frequency and a shortening of the settling time.

[0133] While this invention has been described with respect to at least one embodiment, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.

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F02D2250/18

MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING

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F02D31/003

MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING

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H02P9/04

ELECTRICITY

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H02P2205/07

ELECTRICITY

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F02D41/062

MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING

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F02D41/1401

MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING

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F02D29/06

MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING

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F02D2041/1419

MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING

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H02P9/008

ELECTRICITY

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H02P2101/25

ELECTRICITY

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H02P9/04

ELECTRICITY

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F02D41/14

MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING

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F02D29/06

MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING

Abstract

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Description