Method and device for controlling active power distribution of multi-machine parallel system

Abstract

The invention relates to the technical field of new energy power generation control, in particular to a control method and device for active power distribution of a multi-machine parallel system, and the method comprises the steps: constructing a target control structure of the multi-machine parallel system; wherein the multi-machine parallel system is a parallel system of a plurality of electrolytic hydrogen production units, and a k / (1 + Ts) expression is introduced into a phase feed-forward path of the target control structure, then, based on a circuit topology structure of the multi-machine parallel system, an active power expression allocated to each electrolytic hydrogen production unit is obtained, and finally, an active power expression allocated to each electrolytic hydrogen production unit is obtained. And on the basis of the target control structure and the active power expressions allocated by the electrolytic hydrogen production units, constructing the equivalent closed-loop model of the multi-machine parallel system, and performing active power allocation on the electrolytic hydrogen production units by using the equivalent closed-loop model, so that the technical scheme can accurately realize active power allocation according to the rated capacity.

Description

Technical Field

[0001] The present invention relates to the technical field of renewable energy power generation control, and in particular to a control method and device for active power distribution of a multi-machine parallel system. Background Art

[0002] As an important way to achieve carbon neutrality and promote green transformation of energy structure, hydrogen production provides a stable and reliable solution for power energy demand and consumption. In actual power systems, a single power supply cannot meet the actual load demand. In order to increase the capacity of the microgrid system and improve the power supply reliability of the system, multiple inverters are often used in parallel operation. Whether the functions of multiple machines (i.e., multiple electrolysis hydrogen production units) in parallel are distributed according to the rated value ratio will directly affect the power supply capacity of the system.

[0003] However, the current solution to the active power distribution problem in multi-machine parallel systems cannot accurately achieve active power distribution according to rated capacity.

[0004] Therefore, the present invention proposes a control method and device for active power distribution of a multi-machine parallel system to solve the above technical problems. Summary of the invention

[0005] The invention describes a control method and device for active power distribution of a multi-machine parallel system, which can accurately realize active power distribution according to rated capacity.

[0006] According to a first aspect, the present invention provides a control method for active power distribution of a multi-machine parallel system, comprising:

[0007] Constructing a target control structure of a multi-machine parallel system; wherein the multi-machine parallel system is a parallel system of multiple electrolysis hydrogen production units, and introducing an expression of k / (1+Ts) in a phase feedforward path of the target control structure;

[0008] Based on the circuit topology of the multi-machine parallel system, an expression for the active power allocated to each of the electrolytic hydrogen production units is obtained;

[0009] Based on the target control structure and the active power expression allocated to each of the hydrogen production electrolysis units, an equivalent closed-loop model of the multi-machine parallel system is constructed, so as to use the equivalent closed-loop model to allocate active power to each of the hydrogen production electrolysis units.

[0010] According to a second aspect, a control device for active power distribution of a multi-machine parallel system includes:

[0011] A construction unit is configured to construct a target control structure of a multi-machine parallel system; wherein the multi-machine parallel system is a parallel system of multiple electrolysis hydrogen production units, and an expression of k / (1+Ts) is introduced in a phase feedforward path of the target control structure;

[0012] A determination unit is configured to determine an expression for the active power allocated to each of the electrolysis hydrogen production units based on a circuit topology of the multi-machine parallel system;

[0013] The allocation unit is configured to construct an equivalent closed-loop model of the multi-machine parallel system based on the target control structure and the active power expression allocated to each of the electrolytic hydrogen production units, so as to allocate active power to each of the electrolytic hydrogen production units using the equivalent closed-loop model.

[0014] In a third aspect, an embodiment of this specification further provides an electronic device, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the method described in any embodiment of this specification is implemented.

[0015] In a fourth aspect, an embodiment of the present specification further provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed in a computer, the computer is caused to execute the method described in any embodiment of the present specification.

[0016] According to a control method and device for active power distribution of a multi-machine parallel system provided by the present invention, a target control structure of the multi-machine parallel system is constructed; wherein the multi-machine parallel system is a parallel system of multiple electrolytic hydrogen production units, and the expression of k / (1+Ts) is introduced in the phase feedforward path of the target control structure, and then, based on the circuit topology of the multi-machine parallel system, the active power expression allocated to each electrolytic hydrogen production unit is obtained, and finally, based on the target control structure and the active power expression allocated to each electrolytic hydrogen production unit, an equivalent closed-loop model of the multi-machine parallel system is constructed, so as to use the equivalent closed-loop model to distribute active power to each electrolytic hydrogen production unit. Therefore, the above technical scheme can accurately realize the active power distribution according to the rated capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 A schematic flow chart of a control method for active power distribution in a multi-machine parallel system according to an embodiment is shown;

[0019] Figure 2 A schematic block diagram of a control device for active power distribution of a multi-machine parallel system according to an embodiment is shown;

[0020] Figure 3A circuit topology diagram of a multi-machine parallel system according to an embodiment is shown;

[0021] Figure 4 A target control structure diagram of a multi-machine parallel system according to an embodiment is shown;

[0022] Figure 5 An equivalent closed-loop model diagram before improvement according to an embodiment is shown;

[0023] Figure 6 An equivalent closed-loop model diagram according to one embodiment is shown;

[0024] Figure 7 shows a waveform diagram of active power distribution before improvement according to one embodiment;

[0025] Figure 8 A waveform diagram of active power distribution of two improved parallel electrolysis hydrogen production units according to one embodiment is shown;

[0026] Fig. 9 A waveform diagram of active power distribution of three improved parallel electrolysis hydrogen production units according to one embodiment is shown. DETAILED DESCRIPTION

[0027] The solution provided by the present invention is described below in conjunction with the accompanying drawings.

[0028] Figure 1 FIG. 1 is a flow chart of a control method for active power distribution of a multi-machine parallel system according to an embodiment. It can be understood that the method can be executed by any device, equipment, platform, or device cluster with computing and processing capabilities. Figure 1 As shown, the method includes:

[0029] Step 100, constructing a target control structure of a multi-machine parallel system; wherein the multi-machine parallel system is a parallel system of multiple electrolysis hydrogen production units, and introducing an expression of k / (1+Ts) in a phase feedforward path of the target control structure;

[0030] Step 102: based on the circuit topology of the multi-machine parallel system, obtain the active power expression allocated to each electrolytic hydrogen production unit;

[0031] Step 104: Based on the target control structure and the active power expression allocated to each hydrogen electrolysis unit, an equivalent closed-loop model of the multi-machine parallel system is constructed to allocate active power to each hydrogen electrolysis unit using the equivalent closed-loop model.

[0032] See also Figure 3 to Figure 4In this embodiment, a target control structure of a multi-machine parallel system is constructed; wherein the multi-machine parallel system is a parallel system of multiple electrolytic hydrogen production units, and an expression of k / (1+Ts) is introduced in the phase feedforward path of the target control structure, the influence of parameter coupling is eliminated by deleting the original damping (i.e., removing the damping D in the target control structure below), and a compensation term is introduced in the phase feedforward path to provide damping for the system, and sufficient damping support can be provided for the system by setting appropriate k and T, and there is no coupling relationship between the parameters in the compensation term and the frequency modulation coefficient, and then, based on the circuit topology of the multi-machine parallel system, an expression of active power allocated to each electrolytic hydrogen production unit is obtained, and finally, based on the target control structure and the expression of active power allocated to each electrolytic hydrogen production unit, an equivalent closed-loop model of the multi-machine parallel system is constructed, so as to use the equivalent closed-loop model to distribute active power to each electrolytic hydrogen production unit, therefore, the above technical scheme can accurately realize active power distribution according to rated capacity.

[0033] In one embodiment of the present invention, the active power expression is:

[0034]

[0035] In the formula, i and j represent the serial number of the electrolytic hydrogen production unit, ΔP load is the disturbance of the public load, S E is the synchronous power factor, ω n is the rated angular frequency, ΔP i The expression for the active power allocated to the i-th electrolysis hydrogen production unit.

[0036] In some implementations, the damping term of the target control structure is removed to eliminate the coupling relationship between the damping and the frequency modulation coefficient, where the active loop equation is:

[0037]

[0038] Among them, P ref is the reference active value, P e is the output active power, J is the inertia parameter, k p is the frequency modulation coefficient, ω n is the rated angular frequency.

[0039] However, this will weaken the damping characteristics of the system, and a new damping term needs to be introduced. At the same time, the coupling between the new damping and the frequency modulation coefficient should be avoided. Based on the above considerations, the expression k / (1+Ts) is introduced in the phase feedforward path, and the new active loop equation is:

[0040]

[0041] It can be seen from the above formula that the improved target control structure can not only provide damping support for the system by setting k and T, but also realize the decoupling of damping and frequency modulation coefficients.

[0042] In one embodiment of the present invention, step 104 includes:

[0043] Based on the equivalent closed-loop model and the target control structure, the open-loop transfer function of each electrolytic hydrogen production unit is obtained;

[0044] Based on the open-loop transfer function and the equivalent closed-loop model, the closed-loop transfer function assigned to each electrolytic hydrogen production unit is obtained;

[0045] Based on the closed-loop transfer function, the active power distribution of each electrolytic hydrogen production unit is obtained.

[0046] See also Figure 5 In this embodiment, the Figure 3 And the circuit relationship, we can get the active power expression allocated to the i-th unit, which is determined by the following formula:

[0047]

[0048] Wherein, δ is the phase difference between the electrolytic hydrogen production unit and the load.

[0049] For a clearer explanation, taking two parallel units as an example, the active power expression allocated to the i-th unit is determined by the following formula:

[0050]

[0051] Where i and j represent the unit number, here i = 1, j = 2ori = 2, j = 1, ΔP load is the disturbance of the public load, and the equivalent closed-loop model diagram before improvement is established based on it, as shown in Figure 5 shown.

[0052] For a two-unit parallel system, the open-loop transfer function between the output phase and the distributed power is determined by the following formula:

[0053]

[0054] Where D is the damping, and then the closed-loop transfer function is derived respectively. The closed-loop transfer function is determined by the following formula:

[0055]

[0056] Where ΔP VSG,i is the small disturbance component of the output power of each unit.

[0057] Furthermore, the active power distribution of each electrolytic hydrogen production unit is:

[0058]

[0059] According to the above formula, if the active power distribution between parallel units is to satisfy k P1 / k P2 =1:2, then D1 / D2=1:2. From the above formula, we can see that the active power sharing ratio depends on both the frequency modulation coefficient and the damping. When k p1 :k p2 =1:2, the changes in D1 and D2 will have a significant impact on power distribution, indicating that the multi-machine parallel system cannot distribute active power according to the rated capacity ratio due to the existence of damping.

[0060] See also Figure 6 , in one embodiment of the present invention, the open-loop transfer function is:

[0061]

[0062] Where J is the inertia parameter, k i is the gain factor of the i-th electrolytic hydrogen production unit, T i is the time constant of the i-th electrolysis hydrogen production unit, and s is a complex variable.

[0063] In one embodiment of the present invention, the closed-loop transfer function is:

[0064]

[0065] In the formula, ΔP E_VSG,i is the small disturbance component of the output power of each unit.

[0066] In one embodiment of the present invention, the active power distribution is:

[0067]

[0068] In the formula, k p is the frequency modulation coefficient.

[0069] In this embodiment, active power distribution is only related to the ratio of frequency modulation coefficients and has nothing to do with other parameters, thereby achieving the goal of distributing active power of the multi-machine parallel system in proportion to rated capacity.

[0070] like Figure 7 As shown, in some embodiments, the two parallel units P1 are adjusted from 10kW to 20kW, and P2 is adjusted from 16kW to 26kW. Before the improvement, P1 and P2 are not distributed proportionally in the system. Figure 8 In the above example, the two units P1 and P2 are allocated according to the frequency modulation coefficient of 1:2 to obtain the allocated power. Similarly, in Fig. 9In the process, the three units are allocated according to the frequency modulation coefficient of 1:2:3 to obtain the allocated power.

[0071] It can be clearly seen from the waveform diagram of active power distribution before the improvement that the distributed power of the two electrolysis hydrogen production units cannot accurately achieve active power distribution according to the rated capacity. The existence of damping makes it often impossible for the multi-machine parallel system to accurately distribute active power according to the rated capacity. Whether the active power distribution between the multi-machine parallel systems can be distributed according to the rated value ratio will directly affect the power supply capacity of the system. The improved multi-machine parallel system has solved this problem well.

[0072] According to another embodiment, the present invention provides a control device for active power distribution in a multi-machine parallel system. Figure 2 FIG. 1 is a schematic block diagram of a control device for active power distribution of a multi-machine parallel system according to an embodiment. It is understood that the device can be implemented by any device, equipment, platform and device cluster with computing and processing capabilities. Figure 2 As shown, the device includes: a construction unit 200, a determination unit 202 and an allocation unit 204. The main functions of each component unit are as follows:

[0073] The construction unit 200 is configured to construct a target control structure of a multi-machine parallel system; wherein the multi-machine parallel system is a parallel system of multiple electrolysis hydrogen production units, and an expression of k / (1+Ts) is introduced in a phase feedforward path of the target control structure;

[0074] The determination unit 202 is configured to determine the active power expression allocated to each electrolytic hydrogen production unit based on the circuit topology of the multi-machine parallel system;

[0075] The allocation unit 204 is configured to construct an equivalent closed-loop model of the multi-machine parallel system based on the target control structure and the active power expression allocated to each hydrogen electrolysis unit, so as to allocate active power to each hydrogen electrolysis unit using the equivalent closed-loop model.

[0076] As a preferred implementation, the active power expression is:

[0077]

[0078] In the formula, i and j represent the serial number of the electrolytic hydrogen production unit, ΔP load is the disturbance of the public load, S E is the synchronous power factor, ω n is the rated angular frequency, ΔP i The expression for the active power allocated to the i-th electrolysis hydrogen production unit.

[0079] As a preferred implementation, the open-loop transfer function is:

[0080]

[0081] Where J is the inertia parameter, k i is the gain factor of the i-th electrolytic hydrogen production unit, T i is the time constant of the i-th electrolysis hydrogen production unit, and s is a complex variable.

[0082] As a preferred implementation, the closed-loop transfer function is:

[0083]

[0084] In the formula, ΔP E_VSG,i is the small disturbance component of the output power of each unit.

[0085] As a preferred implementation, active power distribution is:

[0086]

[0087] In the formula, k p is the frequency modulation coefficient.

[0088] The allocation unit 204 may be specifically configured as follows:

[0089] Based on the equivalent closed-loop model and the target control structure, the open-loop transfer function assigned to each electrolytic hydrogen production unit is determined;

[0090] Based on the open-loop transfer function and the equivalent closed-loop model, the closed-loop transfer function assigned to each electrolytic hydrogen production unit is determined;

[0091] Based on the closed-loop transfer function, the active power distribution of each electrolytic hydrogen production unit is obtained.

[0092] According to another embodiment, there is also provided a computer-readable storage medium having a computer program stored thereon, which, when executed in a computer, causes the computer to execute a combination of Figure 1 The method described.

[0093] According to another embodiment of the present invention, an electronic device is provided, including a memory and a processor, wherein an executable code is stored in the memory, and when the processor executes the executable code, the Figure 1 method.

[0094] The various embodiments of the present invention are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0095] Those skilled in the art should be aware that in one or more of the above examples, the functions described in the present invention can be implemented by hardware, software, firmware or any combination thereof. When implemented by software, these functions can be stored in a computer-readable medium or transmitted as one or more instructions or codes on a computer-readable medium.

[0096] The above specific implementation methods further illustrate the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above are only specific implementation methods of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made on the basis of the technical solutions of the present invention should be included in the scope of protection of the present invention.

Claims

1. A control method for active power distribution of a multi-machine parallel system, characterized in that: include: Constructing a target control structure of a multi-machine parallel system; wherein the multi-machine parallel system is a parallel system of multiple electrolysis hydrogen production units, and introducing an expression of k / (1+Ts) in a phase feedforward path of the target control structure; Based on the circuit topology of the multi-machine parallel system, an expression for the active power allocated to each of the electrolytic hydrogen production units is obtained; Based on the target control structure and the active power expression allocated to each of the hydrogen production electrolysis units, an equivalent closed-loop model of the multi-machine parallel system is constructed, so as to use the equivalent closed-loop model to allocate active power to each of the hydrogen production electrolysis units.

2. The method according to claim 1, characterized in that The active power expression is determined by the following formula: In the formula, i and j represent the serial number of the electrolytic hydrogen production unit, ΔP load is the disturbance of the public load, S E is the synchronous power factor, ω n is the rated angular frequency, ΔP i The expression for the active power allocated to the i-th electrolysis hydrogen production unit.

3. The method according to claim 2, characterized in that The method of using the equivalent closed-loop model to distribute active power to each of the electrolysis hydrogen production units includes: Based on the equivalent closed-loop model and the target control structure, an open-loop transfer function allocated to each of the electrolytic hydrogen production units is obtained; Based on the open-loop transfer function and the equivalent closed-loop model, a closed-loop transfer function allocated to each of the electrolytic hydrogen production units is obtained; Based on the closed-loop transfer function, the active power distribution of each of the electrolysis hydrogen production units is obtained.

4. The method according to claim 3, characterized in that The open loop transfer function is determined by the following formula: Where J is the inertia parameter, k i is the gain factor of the i-th electrolytic hydrogen production unit, T i is the time constant of the i-th electrolysis hydrogen production unit, and s is a complex variable.

5. The method according to claim 4, characterized in that The closed-loop transfer function is determined by the following formula: Where ΔP E_VSG,i is the small disturbance component of the output power of each unit.

6. The method according to claim 5, characterized in that The active power distribution is determined by the following formula: In the formula, k p is the frequency modulation coefficient.

7. A control device for active power distribution of a multi-machine parallel system, characterized in that: include: A construction unit is configured to construct a target control structure of a multi-machine parallel system; wherein the multi-machine parallel system is a parallel system of multiple electrolysis hydrogen production units, and an expression of k / (1+Ts) is introduced in a phase feedforward path of the target control structure; A determination unit is configured to determine an expression for the active power allocated to each of the electrolysis hydrogen production units based on a circuit topology of the multi-machine parallel system; The allocation unit is configured to construct an equivalent closed-loop model of the multi-machine parallel system based on the target control structure and the active power expression allocated to each of the electrolytic hydrogen production units, so as to allocate active power to each of the electrolytic hydrogen production units using the equivalent closed-loop model.

8. The device according to claim 7, wherein: The allocation unit is specifically configured as follows: Based on the equivalent closed-loop model, determining the open-loop transfer function assigned to each of the electrolysis hydrogen production units; Determining the closed-loop transfer function assigned to each of the electrolytic hydrogen production units based on the open-loop transfer function and the equivalent closed-loop model; Based on the closed-loop transfer function, the active power distribution of each of the electrolysis hydrogen production units is allocated.

9. An electronic device, characterized in that: The method comprises a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the method according to any one of claims 1 to 6 is implemented.

10. A computer-readable storage medium, characterized in that: A computer program is stored thereon, and when the computer program is executed in a computer, the computer is caused to execute the method according to any one of claims 1 to 6.

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