Power oscillation suppression method and system for grid-connected diesel-storage combined power supply system

Abstract

The present invention discloses a method and system for suppressing power oscillations in a grid-type diesel-storage combined power supply system. The instantaneous active power of the diesel generator and the energy storage converter is introduced into the instantaneous power interleaving feedback compensation branch, the power angle compensation amount of the energy storage converter is calculated, and the output phase of the energy storage converter is adjusted in real time to reduce the phase deviation between the energy storage converter and the diesel generator, thereby achieving the purpose of suppressing power oscillations in the grid-type diesel-storage combined power supply system and significantly improving the collaborative power supply capability of the grid-type diesel-storage combined power supply system under dynamic working conditions.

Description

Technical Field

[0001] The present invention relates to the field of microgrid operation and stability control, and in particular to a method and system for suppressing power oscillations in a grid-connected diesel-storage combined power supply system. Background Art

[0002] In remote areas such as islands, deserts, and rural areas, grid-connected diesel-storage parallel systems, consisting of diesel generators and grid-controlled energy storage converters, are often used to provide reliable power in place of large power grids. While ensuring power supply stability and reliability, this system avoids the high costs of large-scale grid construction and overcomes the inherent drawbacks of single diesel generation, such as low flexibility, poor economic efficiency, and slow response speed. These systems are an important means of ensuring power supply in these areas. In these systems, the energy storage converter can collaboratively share load power variations with the diesel generator based on a preset droop factor, significantly reducing the generator's capacity requirements and helping to stabilize system frequency. However, due to significant differences in physical structure and control parameters between diesel generators and energy storage converters, the parallel system often experiences power oscillations when faced with load power surges.

[0003] Some scholars have proposed some solutions to suppress power oscillations in grid-connected diesel-storage combined power supply systems:

[0004] The existing technology proposes an active oscillation suppression strategy for diesel-storage microgrids (Shi Rongliang, Wang Guobin, Lan Caihua, et al. Active oscillation suppression strategy for diesel-storage microgrids based on active proportional differential feedforward VSG [J]. Renewable Energy, 2024, 42(08): 1074-1082). However, the response speed of the oscillation suppression strategy proposed in this scheme will be affected by the original control parameters of the converter, and the differential link used is not easy to implement in a discrete controller. It is also not suitable for situations where there is a large difference in the capacity of the diesel generator and the energy storage converter.

[0005] Another study proposed two oscillation suppression strategies for diesel-storage parallel systems with pulsed loads (Yi Weilang. Research on key technologies for multi-channel synchronous power supply of special power sources under periodic shock loads [D]. Hunan University, 2023). However, the angular acceleration parameters of the diesel generator used in the control strategy proposed in this scheme are difficult to measure quickly and accurately.

[0006] Patent application CN119134389A proposes a method for suppressing oscillations in a grid-connected parallel diesel-storage system under low-frequency shock loads. However, this method relies on accurately obtaining instantaneous load power parameters. This approach, constrained by the wide geographical distribution of distributed power sources and shock loads at oilfield sites, coupled with engineering constraints such as system communication delays and measurement errors, results in significant limitations in practical engineering applications for control schemes based on real-time load power tracking. Furthermore, this oscillation suppression method is unsuitable for three-phase nonlinear and asymmetric loads.

[0007] In summary, it is difficult for existing methods to take into account both rapid response and engineering feasibility. There is an urgent need for a new power oscillation suppression strategy with rapid response and strong engineering feasibility to improve the collaborative power supply capability of the grid-connected diesel-storage combined power supply system under dynamic conditions. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to provide a method and system for suppressing power oscillations in a grid-type diesel-storage combined power supply system in response to the shortcomings of the existing technology, so as to solve the power oscillation problem caused by the differences in physical structure and control parameters between the diesel generator and the energy storage converter.

[0009] To solve the above technical problems, the technical solution adopted by the present invention is: a method for suppressing power oscillations in a grid-connected diesel-storage combined power supply system, comprising the following steps:

[0010] Sample the instantaneous value u of the three-phase output voltage output by the energy storage converter vga 、u vgb 、u vgc and three-phase current i vga 、i vgb 、i vgc , according to the instantaneous value u of the three-phase output voltage output by the energy storage converter vga 、u vgb 、u vgc and three-phase current i vga 、i vgb 、i vgc Calculate the instantaneous active power P of the energy storage converter vg and instantaneous reactive power Q vg ;

[0011] Sample the instantaneous value u of the three-phase output voltage of the diesel generator dga 、u dgb 、u dgc ;

[0012] Using the phase θ of the output voltage of the energy storage converter vg And the instantaneous value of the three-phase output voltage u of the diesel generator output dga 、u dgb、u dgc Calculate the phase compensation θ of the energy storage converter a ;

[0013] Using the instantaneous active power P of the energy storage converter vg , instantaneous reactive power Q vg and the phase compensation amount θ a Calculate the output voltage amplitude E of the energy storage converter vg and phase θ vg ;

[0014] The output voltage amplitude E of the energy storage converter vg and phase θ vg After PWM modulation, the driving signal K is generated PWM .

[0015] The present invention utilizes the phase θ of the energy storage converter vg And the instantaneous value of the three-phase output voltage of the diesel generator u dga 、u dgb 、u dgc Calculate the phase compensation θ of the energy storage converter a , which can effectively suppress the power oscillation problem caused by the phase inconsistency of the parallel units. The present invention can reduce the phase deviation between the energy storage converter and the diesel generator set by actively compensating the phase of the energy storage converter, thereby suppressing the power oscillation. The present invention does not need to obtain the instantaneous value parameters of the load power, and the implementation of the solution is not limited by the limitations of the place of use, which greatly improves the engineering practicality of the solution. The present invention only needs to collect the instantaneous value of the three-phase output voltage of the diesel generator to achieve effective suppression of power oscillation, without the need to configure a current detection unit. This streamlined design reduces the number of sampling units and significantly improves the reliability and economy of the system.

[0016] In the present invention, the phase compensation amount θ a The calculation formula is: ; Among them, u dga 、u dgb and u dgc are the instantaneous values ​​of the three-phase output voltages of the diesel generator, phase A, phase B and phase C, respectively. a is the compensation proportional coefficient.

[0017] The phase compensation amount of the present invention is generated by calculating the instantaneous value of the three-phase output voltage of the diesel generator and the phase of the grid inverter. Therefore, through voltage and phase calculation alone, it has the ability to suppress oscillations in typical three-phase unbalanced and nonlinear load scenarios, which can effectively avoid the influence of current distortion on the oscillation suppression effect in such scenarios, and significantly improve the robustness of the proposed method.

[0018] In the present invention, the amplitude E of the output voltage of the energy storage converter is vg The calculation formula is: Among them, K q 、U vgn , Q vgn and D q They are the excitation regulation coefficient, rated voltage, rated reactive power and reactive droop coefficient of the energy storage converter respectively.

[0019] The phase θ of the output voltage of the energy storage converter vg The calculation formula is: ; J, D p and ω vgn are the virtual inertia, active droop coefficient and rated angular frequency of the energy storage converter, P vgn is the rated active power of the energy storage converter.

[0020] As an inventive concept, the present invention also provides a power oscillation suppression system for a grid-connected diesel-storage combined power supply system, comprising:

[0021] The first sampling unit is used to sample the instantaneous value u of the three-phase output voltage output by the energy storage converter vga 、u vgb 、u vgc and three-phase current i vga 、i vgb 、i vgc , according to the instantaneous value u of the three-phase output voltage output by the energy storage converter vga 、u vgb 、u vgc and three-phase current i vga 、i vgb 、i vgc Calculate the instantaneous active power P of the energy storage converter vg and instantaneous reactive power Q vg ;

[0022] The second sampling unit is used to sample the instantaneous value u of the three-phase output voltage output by the diesel generator dga 、u dgb 、u dgc ;

[0023] Phase compensation calculation unit, used to use the phase θ of the output voltage of the energy storage converter vg And the instantaneous value of the three-phase output voltage u dga 、u dgb 、u dgc Calculate the phase compensation θ of the energy storage converter a ;

[0024] Amplitude calculation unit, used to use the instantaneous reactive power Q of the energy storage converter vg Calculate the output voltage amplitude E of the energy storage converter vg ;

[0025] Phase calculation unit, used to use the instantaneous active power P of the energy storage converter vg and the phase compensation amount θ a Calculate the phase θ of the output voltage of the energy storage converter vg ;

[0026] Modulation unit, used to adjust the output voltage amplitude E of the energy storage converter vg and phase θ vg After PWM modulation, the driving signal K is generated PWM .

[0027] The phase compensation amount calculation unit calculates the phase compensation amount θ using the following formula a : Among them, P dgn and P vgn are the rated active power of the diesel generator and the rated active power of the energy storage converter, K a and K f are the compensation proportional coefficient and the compensation feedback coefficient.

[0028] The amplitude calculation unit calculates the amplitude E of the output voltage of the energy storage converter using the following formula: vg : Among them, K q 、U vgn , Q vgn and D q They are the excitation regulation coefficient, rated voltage, rated reactive power and reactive droop coefficient of the energy storage converter respectively.

[0029] The phase calculation unit calculates the phase θ of the output voltage of the energy storage converter using the following formula: vg : ; J 、 D p and ω vgn are the virtual inertia, active droop coefficient and rated angular frequency of the energy storage converter, P vgn is the rated active power of the energy storage converter.

[0030] As an inventive concept, the present invention also provides a grid-type diesel-storage combined power supply control system, including one or more processors and a memory; one or more programs are stored on the memory, and when the one or more programs are executed by the one or more processors, the one or more processors implement the steps of the above method.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] (1) The present invention introduces an instantaneous phase feedback compensation branch into the control system of the energy storage converter, which can effectively suppress the power oscillation of the grid-type diesel-storage combined power supply system.

[0033] (2) While achieving power oscillation suppression in a grid-type diesel-storage combined power supply system, the present invention does not require any additional adjustments to the diesel generator control system. In addition, the present invention does not require simultaneous acquisition of voltage and current information to calculate load power, and has fewer sampling units, thereby reducing program complexity and implementation difficulty.

[0034] (3) Compensation parameter K of the proposed method a The setting has a certain adjustable window without relying on complex and precise calculations. In addition, the additional branch is set in parallel with the original control loop. Therefore, the oscillation suppression effect of the proposed control is not affected by changes in the original control parameters of the VSG, which improves the robustness and deployment convenience of the method.

[0035] (4) The present invention achieves power oscillation suppression in a grid-type diesel-storage combined power supply system without changing the steady-state power distribution of the diesel generator and the energy storage converter. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 Schematic diagram of the structure of a diesel-storage multi-port power supply system in an embodiment of the present invention;

[0037] Figure 2 This is a schematic diagram of a method for suppressing power oscillations in a grid-connected diesel-storage combined power supply according to an embodiment of the present invention;

[0038] Figure 3 This is a control block diagram of the instantaneous power interleaving feedback compensation branch according to an embodiment of the present invention;

[0039] Figure 4 This is a simulation waveform diagram of the output power of a grid-type diesel-storage combined power supply system when a traditional control method is adopted in an embodiment of the present invention;

[0040] Figure 5 This is a simulation waveform diagram of the output power of a grid-type diesel-storage combined power supply system when the oscillation suppression method is adopted in an embodiment of the present invention. DETAILED DESCRIPTION

[0041] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0042] Example 1

[0043] like Figure 1 As shown in FIG, the diesel-storage multi-port power supply system structure under low-frequency pulse load of the embodiment of the present invention includes a diesel generator and at least one energy storage converter. Figure 1 In, X dg1 is the output impedance of the diesel generator; X vg1 ~X vgn is the output impedance of the first to nth energy storage converters; the diesel generator and the energy storage converter are connected to the same AC bus through the output impedance and the load, which includes conventional load and dynamic load.

[0044] like Figure 2 As shown, the grid-connected diesel-storage combined power supply power oscillation suppression method of an embodiment of the present invention includes the following steps.

[0045] Step 1: Sampling and power calculation.

[0046] Step 1.1 Sample the instantaneous value u of the three-phase output voltage output by the energy storage converter vga 、u vgb 、u vgc and three-phase current i vga 、i vgb 、i vgc , according to the instantaneous value u of the three-phase output voltage output by the energy storage converter vga 、u vgb 、u vgc and three-phase current i vga 、i vgb 、i vgc Calculate the instantaneous active power P of the energy storage converter vg and instantaneous reactive power Q vg ;

[0047] Step 1.2 Sample the instantaneous value u of the three-phase output voltage of the diesel generator dga 、u dgb 、u dgc .

[0048] Step 2: Calculate the phase compensation amount.

[0049] The energy storage converter phase θ calculated in step 1 vg And the instantaneous value of the three-phase output voltage u dga 、u dgb 、u dgc Introducing the deviation phase feedback compensation branch to calculate the phase compensation amount θ of the energy storage converter a , the specific calculation formula is:

[0050] ;

[0051] Among them, udga 、u dgb and u dgc They are the instantaneous values ​​of the three-phase output voltage of the diesel generator phase A, phase B and phase C, respectively, K a is the compensation proportional coefficient.

[0052] Step 3: Calculate the amplitude and phase of the output voltage.

[0053] The instantaneous active power P of the energy storage converter calculated in step 1 is vg , instantaneous reactive power Q vg And the phase compensation amount θ of the energy storage converter calculated in step 2 a Calculate the output voltage amplitude E of the energy storage converter vg and phase θ vg , the specific calculation formula is:

[0054] ;

[0055] Among them, K q 、U vgn , Q vgn and D q are the excitation regulation coefficient, rated voltage, rated reactive power and reactive droop coefficient of the energy storage converter; J, D p and ω vgn are the virtual inertia, active power droop coefficient and rated angular frequency of the energy storage converter respectively.

[0056] Step 4: Generate driving signal.

[0057] The output voltage amplitude E of the energy storage converter calculated in step 3 is vg and phase θ vg After PWM modulation, the driving signal K is generated PWM .

[0058] like Figure 3 As shown, in the instantaneous phase feedback compensation branch of the embodiment of the present invention, the instantaneous value u of the three-phase output voltage of the diesel generator dga 、u dgb 、u dgc As the input quantity, the instantaneous value of the three-phase output voltage u dga 、u dgb 、u dgc The output voltage phase θ of the energy storage converter vg After introducing the instantaneous phase feedback compensation branch, the generated phase compensation amount θ a , the specific calculation formula is:

[0059] ;

[0060] After sorting, we can get:

[0061] ;

[0062] Among them, U dg is the amplitude of the diesel generator output voltage, which can generally be considered constant. It can be seen that when θ dg <θ vg When θ a is positive, otherwise it is negative. In addition, in the instantaneous phase feedback compensation branch, K a The larger it is, the more significant the effect of the instantaneous phase feedback compensation branch is.

[0063] The power oscillation of the system is caused by the inconsistency of the output phases of the diesel generator and the energy storage inverter. dg >θ vg When the energy storage converter output power P vg Insufficient; on the contrary, when θ dg <θ vg When the energy storage converter output power P vg Therefore, when there is power oscillation in the grid-type diesel-storage combined power supply system, θ dg >θ vg When θ a will rise, increasing the output voltage phase θ of the energy storage converter vg , which can make the instantaneous active power P of the energy storage converter vg Increase; on the contrary, when there is power oscillation in the grid-type diesel-storage combined power supply system, θ dg <θ vg When θ a will drop, reducing the output voltage phase θ of the energy storage converter vg , which can make the instantaneous active power P of the energy storage converter vg Reduced; When there is no power oscillation in the grid-type diesel-storage combined power supply system, there is θ dg =θ vg , at this time θ a The value will be maintained at zero, ensuring that the steady-state output power of the diesel generator and energy storage converter is not affected by the phase compensation amount θ a impact.

[0064] like Figure 4 As shown in the output power simulation model diagram of the grid-type diesel-storage combined power supply system when using the traditional control method, when the load power suddenly increases from 10kW to 30kW, the output power of the diesel generator and the energy storage converter both have obvious oscillations, with a power oscillation amplitude of 5.1kW. After the oscillation ends, the steady-state values ​​of the instantaneous active power of the diesel generator and the energy storage converter are 20kW and 10kW, respectively.

[0065] like Figure 5As shown in the output power simulation model diagram of the grid-connected diesel-electric energy storage combined power supply system using the oscillation suppression method of this embodiment, when the load power suddenly increases from 10 kW to 30 kW, the power oscillation amplitude in the instantaneous active power of the diesel generator and energy storage converter is significantly suppressed, decreasing to 0.8 kW. After the oscillation ends, the steady-state values ​​of the instantaneous active power of the diesel generator and energy storage converter are 20 kW and 10 kW, respectively. These results demonstrate that the oscillation suppression method of this embodiment can effectively suppress power oscillations in the grid-connected diesel-electric energy storage combined power supply system without affecting the steady-state values ​​of the instantaneous active power of the diesel generator and energy storage converter.

[0066] Example 2

[0067] This embodiment provides a power oscillation suppression system for a grid-connected diesel-storage combined power supply system, including:

[0068] The first sampling unit is used to sample the instantaneous value u of the three-phase output voltage output by the energy storage converter vgabc and three-phase current i vgabc , according to the instantaneous value u of the three-phase output voltage output by the energy storage converter vgabc and three-phase current i vgabc Calculate the instantaneous active power P of the energy storage converter vg and instantaneous reactive power Q vg ;

[0069] The second sampling unit is used to sample the instantaneous value u of the three-phase output voltage output by the diesel generator dga 、u dgb 、u dgc ;

[0070] Phase compensation calculation unit, used to use the energy storage converter phase θ vg And the instantaneous value of the three-phase output voltage u of the diesel generator output dga 、u dgb 、u dgc Calculate the phase compensation θ of the energy storage converter a ; ; Among them, u dga 、u dgb and u dgc They are the instantaneous values ​​of the three-phase output voltage of the diesel generator phase A, phase B and phase C, respectively, K a is the compensation proportional coefficient;

[0071] Amplitude calculation unit, used to use the instantaneous reactive power Q of the energy storage converter vg Calculate the output voltage amplitude E of the energy storage converter vg ;

[0072] Phase calculation unit, used to use the instantaneous active power P of the energy storage convertervg and the phase compensation amount θ a Calculate the phase θ of the output voltage of the energy storage converter vg ;

[0073] Modulation unit, used to adjust the output voltage amplitude E of the energy storage converter vg and phase θ vg After PWM modulation, the driving signal K is generated PWM .

[0074] In this embodiment, Among them, K q 、U vgn , Q vgn and D q are the excitation regulation coefficient, rated voltage, rated reactive power and reactive droop coefficient of the energy storage converter; J, D p and ω vgn are the virtual inertia, active power droop coefficient and rated angular frequency of the energy storage converter respectively.

[0075] Example 3

[0076] Embodiment 3 of the present invention provides a control system corresponding to the above-mentioned embodiment 1, including a memory, a processor, and a computer program stored in the memory; the processor executes the computer program in the memory to implement the steps of the method of the above-mentioned embodiment 1.

[0077] In some implementations, the memory may be a high-speed random access memory (RAM), and may also include a non-volatile memory, such as at least one disk storage.

[0078] In other implementations, the processor may be a central processing unit (CPU), a digital signal processor (DSP), or other general-purpose processors, which are not limited herein.

[0079] Example 4

[0080] Embodiment 4 of the present invention provides a computer-readable storage medium corresponding to the above-mentioned embodiment 1, on which a computer program / instruction is stored. When the computer program / instruction is executed by a processor, the steps of the method of the above-mentioned embodiment 1 are implemented.

[0081] Computer readable storage media can be tangible devices that hold and store instructions used by instruction execution devices. Computer readable storage media can be, for example, but not limited to, electronic storage devices, magnetic storage devices, optical storage devices, electromagnetic storage devices, semiconductor storage devices, or any combination thereof.

[0082] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may take the form of a fully hardware embodiment, a fully software embodiment, or an embodiment combining software and hardware. Furthermore, the present application may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code. The solutions in the embodiments of the present application may be implemented in various computer languages, such as the object-oriented programming language Java and the interpreted scripting language JavaScript.

[0083] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0084] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0085] Although the preferred embodiments of the present application have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present application.

[0086] Obviously, those skilled in the art may make various changes and modifications to this application without departing from the spirit and scope of this application. Thus, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalents, this application is intended to include these modifications and variations.

Claims

1. A method for suppressing power oscillations in a grid-connected diesel-storage combined power supply system, characterized in that: The following steps are involved: Sample the instantaneous value u of the three-phase output voltage output by the energy storage converter vga 、u vgb 、u vgc and three-phase current i vga 、i vgb 、i vgc , according to the instantaneous value u of the three-phase output voltage output by the energy storage converter vga 、u vgb 、u vgc and three-phase current i vga 、i vgb 、i vgc Calculate the instantaneous active power P of the energy storage converter vg and instantaneous reactive power Q vg ; Sample the instantaneous value u of the three-phase output voltage of the diesel generator dga 、u dgb 、u dgc ; The phase θ of the output voltage of the energy storage converter is used vg And the instantaneous value of the three-phase output voltage u of the diesel generator dga 、u dgb 、u dgc Calculate the phase compensation θ of the energy storage converter a ; Using the instantaneous active power P of the energy storage converter vg , instantaneous reactive power Q vg and the phase compensation amount θ a Calculate the output voltage amplitude E of the energy storage converter vg and phase θ vg ; The output voltage amplitude E of the energy storage converter vg and phase θ vg After PWM modulation, the driving signal K is generated PWM .

2. The method for suppressing power oscillations in a grid-connected diesel-storage combined power supply system according to claim 1, characterized in that: Phase compensation amount θ a The calculation formula is: ; Among them, u dga 、u dgb and u dgc are the instantaneous values ​​of the three-phase output voltages of the diesel generator, phase A, phase B and phase C, respectively. a is the compensation proportional coefficient.

3. The method for suppressing power oscillations in a grid-connected diesel-storage combined power supply system according to claim 1, characterized in that: The amplitude of the output voltage of the energy storage converter E vg The calculation formula is: ； Among them, K q 、U vgn , Q vgn and D q They are the excitation regulation coefficient, rated voltage, rated reactive power and reactive droop coefficient of the energy storage converter respectively.

4. The method for suppressing power oscillations in a grid-connected diesel-storage combined power supply system according to claim 1, characterized in that: The phase θ of the output voltage of the energy storage converter vg The calculation formula is: ; J, D p and ω vgn are the virtual inertia, active droop coefficient and rated angular frequency of the energy storage converter, P vgn is the rated active power of the energy storage converter.

5. A power oscillation suppression system for a grid-connected diesel-storage combined power supply system, characterized in that: include: The first sampling unit is used to sample the instantaneous value u of the three-phase output voltage output by the energy storage converter vga 、u vgb 、u vgc and three-phase current i vga 、i vgb 、i vgc , according to the instantaneous value u of the three-phase output voltage output by the energy storage converter vga 、u vgb 、u vgc and three-phase current i vga 、i vgb 、i vgc Calculate the instantaneous active power P of the energy storage converter vg and instantaneous reactive power Q vg ; The second sampling unit is used to sample the instantaneous value u of the three-phase output voltage output by the diesel generator dga 、u dgb 、u dgc ; Phase compensation calculation unit, used to use the phase θ of the output voltage of the energy storage converter vg And the instantaneous value of the three-phase output voltage u of the diesel generator dga 、u dgb 、u dgc Calculate the phase compensation θ of the energy storage converter a ; Amplitude calculation unit, used to use the instantaneous reactive power Q of the energy storage converter vg Calculate the output voltage amplitude E of the energy storage converter vg ; Phase calculation unit, used to use the instantaneous active power P of the energy storage converter vg and the phase compensation amount θ a Calculate the phase θ of the output voltage of the energy storage converter vg ; Modulation unit, used to adjust the output voltage amplitude E of the energy storage converter vg and phase θ vg After PWM modulation, the driving signal K is generated PWM .

6. The power oscillation suppression system of the grid-connected diesel-storage combined power supply system according to claim 5 is characterized in that: The phase compensation amount calculation unit calculates the phase compensation amount θ using the following formula a : ; Among them, u dga 、u dgb and u dgc are the instantaneous values ​​of the three-phase output voltages of the diesel generator, phase A, phase B and phase C, respectively. a is the compensation proportional coefficient.

7. The power oscillation suppression system of the grid-connected diesel-storage combined power supply system according to claim 5 is characterized in that: The amplitude calculation unit calculates the amplitude E of the output voltage of the energy storage converter using the following formula: vg : ； Among them, K q 、U vgn , Q vgn and D q They are the excitation regulation coefficient, rated voltage, rated reactive power and reactive droop coefficient of the energy storage converter respectively.

8. The power oscillation suppression system of the grid-connected diesel-storage combined power supply system according to claim 5 is characterized in that: The phase calculation unit calculates the phase θ of the output voltage of the energy storage converter using the following formula: vg : ; J, D p and ω vgn are the virtual inertia, active droop coefficient and rated angular frequency of the energy storage converter, P vgn is the rated active power of the energy storage converter.

9. A grid-type diesel-storage combined power supply control system, characterized in that: The method comprises one or more processors and a memory; the memory stores one or more programs, and when the one or more programs are executed by the one or more processors, the one or more processors implement the steps of the method according to any one of claims 1 to 4.

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