A characteristic test system for parallel operation of multiple virtual synchronous generators

Abstract

The present invention relates to a characteristic test system for parallel operation of multiple virtual synchronous generators. The system includes: controllers corresponding to main circuit simulation models of each virtual synchronous generator, each simulation interface, each DC source simulation model, main circuit simulation models of multiple virtual synchronous generators in parallel, a transformer simulation model, and a power grid simulation device. The characteristic test system for parallel operation of multiple virtual synchronous generators provided by the present invention solves the problem that multiple virtual synchronous generators cannot be tested due to the capacity limitation of the test device, and adjusts the main circuit simulation models of multiple virtual synchronous generators in parallel according to the deviation between the test results of the single-machine type test and the single-machine hardware-in-the-loop test of the virtual synchronous generator, ensuring the accuracy of the multi-machine test results.

Description

Technical Field

[0001] The invention belongs to the field of new energy grid-connected testing, and particularly relates to a characteristic testing system for parallel operation of multiple virtual synchronous generators. Background Technique

[0002] Due to the low inertia level of traditional photovoltaic power stations, the increase in the proportion of large-scale photovoltaic access to the power grid will lead to a decline in the inertia level of the power system and affect the safe and stable operation of the system.

[0003] The virtual synchronous technology can change the photovoltaic power generation characteristics, making it have an external characteristic close to that of conventional thermal power, and has good application prospects and supporting effects for coping with the rapid development of future photovoltaic power generation. Therefore, in order to promote the large-scale development and utilization of new energy, the construction of virtual synchronous generator demonstration projects will be carried out on a large scale.

[0004] However, after the large-scale access of virtual synchronous generators to the power grid, it may have a series of important impacts on the system operation. Therefore, it is necessary to test the external characteristics of its grid-connected operation, especially the virtual synchronous characteristics. At present, limited by the capacity of the testing device, only the grid-connected performance of a single virtual synchronous generator or a power generation unit can be tested, and it is impossible to test the key characteristics such as primary frequency modulation and voltage regulation when multiple virtual synchronous generators are operating in parallel. Therefore, it is necessary to provide a characteristic testing system for parallel operation of multiple virtual synchronous generators. Summary of the Invention

[0005] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a characteristic testing system for parallel operation of multiple virtual synchronous generators. According to the deviation between the test results of the single-machine type test and the single-machine hardware-in-the-loop test of the virtual synchronous generator, the main circuit simulation models of each virtual synchronous generator in parallel are adjusted; then, according to the adjusted main circuit simulation models of each virtual synchronous generator in parallel, a characteristic testing system for parallel operation of multiple virtual synchronous generators with semi-physical simulation is established.

[0006] The purpose of the present invention is realized by the following technical solutions:

[0007] A characteristic testing system for parallel operation of multiple virtual synchronous generators, wherein the system includes: controllers corresponding to the main circuit simulation models of each virtual synchronous generator, each simulation interface, each DC source simulation model, the main circuit simulation models of each virtual synchronous generator in parallel, a transformer simulation model, and a power grid simulation device, and a grid connection point is set between the main circuit simulation models of each virtual synchronous generator in parallel and the transformer simulation model;

[0008] Each of the DC source simulation models is respectively connected to the main circuit simulation models of each virtual synchronous generator in parallel;

[0009] Each main circuit simulation model of the virtual synchronous generators in multi - machine parallel connection is connected to the power grid simulation device through the transformer simulation model;

[0010] The controllers corresponding to each main circuit simulation model of the virtual synchronous generators are respectively connected to each main circuit simulation model of the virtual synchronous generators in multi - machine parallel connection through each simulation interface to perform the interaction of digital signals and analog signals.

[0011] Preferably, the system further includes:

[0012] A single - machine type - test module, which is used to connect the virtual synchronous generator corresponding to a single main circuit simulation model of the virtual synchronous generators in multi - machine parallel connection to a pre - established single - machine type - test system, and perform single - machine type - test on the virtual synchronous generator corresponding to the single main circuit simulation model of the virtual synchronous generators;

[0013] A single - machine hardware - in - the - loop test module, which is used to connect a single main circuit simulation model of the virtual synchronous generators in multi - machine parallel connection and its corresponding controller to a pre - established single - machine hardware - in - the - loop test system, and perform single - machine hardware - in - the - loop test on the controller corresponding to the single main circuit simulation model of the virtual synchronous generators;

[0014] An adjustment module, which is used to adjust each main circuit simulation model of the virtual synchronous generators in multi - machine parallel connection by using the test results of the single - machine type - test and the test results of the single - machine hardware - in - the - loop test respectively.

[0015] Furthermore, the pre - established single - machine type - test system includes: a DC source, a virtual synchronous generator corresponding to a single main circuit simulation model of the virtual synchronous generators, a transformer, and a power grid simulation device connected in sequence;

[0016] Wherein, a connection point is set between the virtual synchronous generator corresponding to the single main circuit simulation model of the virtual synchronous generators and the transformer.

[0017] Specifically, the single - machine type - test module is specifically used for:

[0018] When controlling the output power of the virtual synchronous generator corresponding to the single main circuit simulation model of the virtual synchronous generators to be maintained at 20% - 30% of the rated power through the DC source, continuously change the output frequency of the power grid simulation device, with the holding time of each output frequency being not less than 30 seconds, obtain the voltage and current at the connection point, and calculate the active power and reactive power according to the voltage and current.

[0019] While controlling the output power of the virtual synchronous generator corresponding to the single virtual synchronous generator main circuit simulation model through the DC source to remain at 70% to 90% of the rated power, continuously change the output frequency of the power grid simulation device, with the holding time of each output frequency being no less than 30 seconds, obtain the voltage and current at the grid connection point, and calculate the active power and reactive power based on this voltage and current;

[0020] While controlling the output power of the virtual synchronous generator corresponding to the single virtual synchronous generator main circuit simulation model through the DC source to remain at 50% of the rated power, continuously change the output voltage of the power grid simulation device, with the holding time of each output voltage being no less than 30 seconds, obtain the voltage and current at the grid connection point, and calculate the active power and reactive power based on this voltage and current.

[0021] Furthermore, the pre-established single-machine hardware-in-the-loop test system includes: a controller corresponding to the single virtual synchronous generator main circuit simulation model, a simulation interface, a DC source simulation model, a single virtual synchronous generator main circuit simulation model, a transformer simulation model, and a power grid simulation device;

[0022] The DC source simulation model, the single virtual synchronous generator main circuit simulation model, the transformer simulation model, and the power grid simulation device are connected in sequence;

[0023] The controller corresponding to the single virtual synchronous generator main circuit simulation model is connected to the single virtual synchronous generator main circuit simulation model through the simulation interface for the interaction of digital signals and analog signals;

[0024] Among them, a grid connection point is set between the single virtual synchronous generator main circuit simulation model and the transformer simulation model.

[0025] Specifically, the single-machine hardware-in-the-loop test module is specifically used for:

[0026] While controlling the output power of the single virtual synchronous generator main circuit simulation model through the DC source simulation model to remain at 20% to 30% of the rated power, continuously change the output frequency of the power grid simulation device, with the holding time of each output frequency being no less than 30 seconds, obtain the voltage and current at the grid connection point, and calculate the active power and reactive power based on this voltage and current;

[0027] While controlling the output power of the single virtual synchronous generator main circuit simulation model through the DC source simulation model to remain at 70% to 90% of the rated power, continuously change the output frequency of the power grid simulation device, with the holding time of each output frequency being no less than 30 seconds, obtain the voltage and current at the grid connection point, and calculate the active power and reactive power based on this voltage and current.

[0028] While controlling the output power of the single virtual synchronous generator main circuit simulation model through the DC source simulation model to remain at 50% of the rated power, continuously change the output voltage of the power grid simulation device, with the holding time of each output voltage being not less than 30 seconds, obtain the voltage and current at the grid connection point, and calculate the active power and reactive power based on this voltage and current.

[0029] Specifically, the adjustment module is specifically used for:

[0030] If the deviation between the test results of the virtual synchronous generator corresponding to the single virtual synchronous generator main circuit simulation model in the pre-established single-machine type test system and the test results of the controller corresponding to the single virtual synchronous generator main circuit simulation model in the pre-established single-machine hardware-in-the-loop test system under the same operating environment is less than the preset threshold, then do not adjust the main circuit simulation models of the virtual synchronous generators in the multi-machine parallel connection. Otherwise, adjust the inductance and capacitance in the main circuit simulation models of the virtual synchronous generators in the multi-machine parallel connection until the deviation is less than the preset threshold.

[0031] Compared with the closest prior art, the beneficial effects of the present invention are reflected in:

[0032] Based on the single-machine hardware-in-the-loop test system, the present invention provides a characteristic test system for the parallel operation of multiple virtual synchronous generators, solving the problem that it is impossible to conduct tests on multiple virtual synchronous generators due to the capacity limitation of the test device.

[0033] The present invention adjusts the main circuit simulation models of the virtual synchronous generators in the multi-machine parallel connection according to the deviation between the test results of the single-machine type test and the single-machine hardware-in-the-loop test of the virtual synchronous generator, ensuring the accuracy of the multi-machine test results.

[0034] The controllers corresponding to the main circuit simulation models of the virtual synchronous generators in the present invention are real controllers, which are the core part determining the control performance of the virtual synchronous generator. Compared with the existing digital simulation evaluation technology, it is not necessary to identify the inverter control model, and the characteristic test of the parallel operation of multiple virtual synchronous generators can be more accurately realized. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 is a schematic structural diagram of a characteristic test system for the parallel operation of multiple virtual synchronous generators in an embodiment of the present invention;

[0036] Figure 2 is a schematic structural diagram of a pre-established single-machine type test system in an embodiment of the present invention;

[0037] Figure 3It is a schematic structural diagram of a single-machine hardware-in-the-loop test system pre-established in an embodiment of the present invention. Specific Embodiments

[0038] The following further elaborates on the specific embodiments of the present invention in conjunction with the accompanying drawings.

[0039] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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 some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0040] A characteristic test system for the parallel operation of multiple virtual synchronous generators, as Figure 1 shown, the system includes: controllers corresponding to the main circuit simulation models of each virtual synchronous generator, each simulation interface, each DC source simulation model, the main circuit simulation models of multiple virtual synchronous generators in parallel, a transformer simulation model, and a power grid simulation device. A connection point is set between the main circuit simulation models of multiple virtual synchronous generators in parallel and the transformer simulation model;

[0041] Each of the DC source simulation models is respectively connected to the main circuit simulation models of multiple virtual synchronous generators in parallel;

[0042] The main circuit simulation models of multiple virtual synchronous generators in parallel are all connected to the power grid simulation device through the transformer simulation model;

[0043] The controllers corresponding to the main circuit simulation models of each virtual synchronous generator are respectively connected to the main circuit simulation models of multiple virtual synchronous generators in parallel through each simulation interface to perform the interaction of digital signals and analog signals.

[0044] Among them, the controllers corresponding to the main circuit simulation models of each virtual synchronous generator are used to make the controllers in the virtual synchronous generator have characteristics similar to those of a synchronous generator by simulating the mechanical characteristics and electromagnetic characteristics of the virtual synchronous generator.

[0045] Further, the system further includes:

[0046] A single-machine type test module, which is used to connect the virtual synchronous generator corresponding to a single virtual synchronous generator main circuit simulation model among the main circuit simulation models of multiple virtual synchronous generators in parallel to a pre-established single-machine type test system, and perform a single-machine type test on the virtual synchronous generator corresponding to the single virtual synchronous generator main circuit simulation model;

[0047] The single - machine hardware - in - the - loop test module is used to connect a single virtual synchronous generator main - circuit simulation model and its corresponding controller in each virtual synchronous generator main - circuit simulation model with multi - machine parallel connection into a pre - established single - machine hardware - in - the - loop test system, and conduct single - machine hardware - in - the - loop tests on the controller corresponding to the single virtual synchronous generator main - circuit simulation model;

[0048] The adjustment module is used to adjust each virtual synchronous generator main - circuit simulation model with multi - machine parallel connection by using the test results of the single - machine type - test and the test results of the single - machine hardware - in - the - loop test respectively;

[0049] The single - machine type - test module, the single - machine hardware - in - the - loop test module, and the adjustment module are put into use before establishing a characteristic test system for multi - machine parallel operation of virtual synchronous generators.

[0050] Specifically, as Figure 2 shown, the pre - established single - machine type - test system includes: a DC source, a virtual synchronous generator corresponding to a single virtual synchronous generator main - circuit simulation model, a transformer, and a power - grid simulation device connected in sequence;

[0051] Among them, a connection point is set between the virtual synchronous generator corresponding to the single virtual synchronous generator main - circuit simulation model and the transformer.

[0052] Specifically, the single - machine type - test module is specifically used for:

[0053] When controlling the output power of the virtual synchronous generator corresponding to the single virtual synchronous generator main - circuit simulation model to remain at 20% - 30% of the rated power through the DC source, continuously change the output frequency of the power - grid simulation device, with the holding time of each output frequency being not less than 30 seconds, obtain the voltage and current at the connection point, and calculate the active power and reactive power according to the voltage and current;

[0054] When controlling the output power of the virtual synchronous generator corresponding to the single virtual synchronous generator main - circuit simulation model to remain at 70% - 90% of the rated power through the DC source, continuously change the output frequency of the power - grid simulation device, with the holding time of each output frequency being not less than 30 seconds, obtain the voltage and current at the connection point, and calculate the active power and reactive power according to the voltage and current;

[0055] While controlling the output power of the virtual synchronous generator corresponding to the single virtual synchronous generator main circuit simulation model through the DC source to remain at 50% of the rated power, continuously change the output voltage of the power grid simulation device, with the holding time of each output voltage being not less than 30 seconds, obtain the voltage and current at the grid connection point, and calculate the active power and reactive power based on this voltage and current.

[0056] Specifically, as Figure 3 shown, the pre-established single-machine hardware-in-the-loop test system includes: a controller corresponding to the single virtual synchronous generator main circuit simulation model, a simulation interface, a DC source simulation model, a single virtual synchronous generator main circuit simulation model, a transformer simulation model, and a power grid simulation device;

[0057] The DC source simulation model, the single virtual synchronous generator main circuit simulation model, the transformer simulation model, and the power grid simulation device are connected in sequence;

[0058] The controller corresponding to the single virtual synchronous generator main circuit simulation model is connected to the single virtual synchronous generator main circuit simulation model through the simulation interface for the interaction of digital signals and analog signals;

[0059] Among them, a grid connection point is set between the single virtual synchronous generator main circuit simulation model and the transformer simulation model.

[0060] Specifically, the single-machine hardware-in-the-loop test module is specifically used for:

[0061] While controlling the output power of the single virtual synchronous generator main circuit simulation model through the DC source simulation model to remain at 20% - 30% of the rated power, continuously change the output frequency of the power grid simulation device, with the holding time of each output frequency being not less than 30 seconds, obtain the voltage and current at the grid connection point, and calculate the active power and reactive power based on this voltage and current;

[0062] While controlling the output power of the single virtual synchronous generator main circuit simulation model through the DC source simulation model to remain at 70% - 90% of the rated power, continuously change the output frequency of the power grid simulation device, with the holding time of each output frequency being not less than 30 seconds, obtain the voltage and current at the grid connection point, and calculate the active power and reactive power based on this voltage and current;

[0063] While controlling the output power of the single virtual synchronous generator main circuit simulation model through the DC source simulation model to remain at 50% of the rated power, continuously change the output voltage of the power grid simulation device, with the holding time of each output voltage being not less than 30 seconds, obtain the voltage and current at the grid connection point, and calculate the active power and reactive power based on this voltage and current.

[0064] Specifically, the adjustment module is specifically used for:

[0065] If the deviation between the test results of the virtual synchronous generator corresponding to the single virtual synchronous generator main circuit simulation model in the pre-established single-machine type test system and the test results of the controller corresponding to the single virtual synchronous generator main circuit simulation model in the pre-established single-machine hardware-in-the-loop test system under the same operating environment is less than the preset threshold, then do not adjust the main circuit simulation models of the virtual synchronous generators in the multi-machine parallel connection. Otherwise, adjust the inductance and capacitance in the main circuit simulation models of the virtual synchronous generators in the multi-machine parallel connection until the deviation is less than the preset threshold.

[0066] Based on the characteristic test system for the multi-machine parallel operation of the virtual synchronous generator, the characteristics of the virtual synchronous generator during multi-machine parallel operation can be tested. Specifically, the active frequency modulation coefficient and the reactive voltage regulation coefficient are tested. The test process is as follows:

[0067] When controlling the output power of the single virtual synchronous generator main circuit simulation model by the DC source simulation model to be maintained at 20% - 30% of the rated power, change the output frequency of the power grid simulation device in sequence as described in Table 1. The holding time for each output frequency is not less than 30 seconds. Obtain the voltage and current at the grid connection point, calculate the active power and reactive power based on this voltage and current, and calculate the active frequency modulation coefficient based on the change in the active power and the output frequency of the power grid simulation device. Take the average of all the active frequency modulation coefficients to obtain the average active frequency modulation coefficient;

[0068] When controlling the output power of the single virtual synchronous generator main circuit simulation model by the DC source simulation model to be maintained at 70% - 90% of the rated power, change the output frequency of the power grid simulation device in sequence as described in Table 1. The holding time for each output frequency is not less than 30 seconds. Obtain the voltage and current at the grid connection point, calculate the active power and reactive power based on this voltage and current, and calculate the active frequency modulation coefficient based on the change in the active power and the output frequency of the power grid simulation device. Take the average of all the active frequency modulation coefficients to obtain the average active frequency modulation coefficient;

[0069] Table 1

[0070] Serial number Output frequency (f, Hz) of the power grid simulation device 1 48.5 2 49.0 3 49.8 4 49.9 5 50.1 6 50.2 7 50.4 8 51.0

[0071] Determine the active frequency modulation coefficient K according to the following formula f :

[0072]

[0073] Where, △f is the change in the output frequency of the power grid simulation device compared to the output frequency before the last frequency change, △P is the change in the active power of the virtual synchronous generator compared to the corresponding active power before the last frequency change of the power grid simulation device, and P N is the rated active power of the virtual synchronous generator, and f N is the rated output frequency of the power grid simulation device;

[0074] While controlling the output power of the single virtual synchronous generator main circuit simulation model to remain at 50% of the rated power through the DC source simulation model, the output voltage of the power grid simulation device is sequentially changed according to 0.9 times, 0.95 times, 1.05 times, and 1.1 times of the rated voltage of the power grid simulation device. The holding time of each output voltage is not less than 30 seconds. The voltage and current at the grid connection point are obtained, the active power and reactive power are calculated based on this voltage and current, and the reactive power voltage regulation coefficient is calculated based on the change in the reactive power and the output voltage of the power grid simulation device model. The average reactive power voltage regulation coefficient is obtained by taking the average of all the reactive power voltage regulation coefficients;

[0075] The reactive power voltage regulation coefficient K is determined according to the following formula QV :

[0076]

[0077] Where, △U is the change in the output voltage of the power grid simulation device compared to the output voltage before the last voltage change, △Q is the change in the reactive power of the virtual synchronous generator compared to the corresponding reactive power before the last voltage change of the power grid simulation device, and P N is the rated active power of the virtual synchronous generator, and U N is the rated output voltage of the power grid simulation device.

[0078] Those skilled in the art should understand that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can adopt 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.

[0079] This application is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to embodiments of the present application. It should be understood that each flow and / or block in the flowchart and / or block diagram, as well as the combination of flows 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 the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, such that the instructions executed by the processor of the computer or other programmable data processing devices generate a device for implementing the functions specified in the Figure 1 one or more flows and / or blocks Figure 1 functions specified in one or more blocks.

[0080] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, such that the instructions stored in the computer-readable memory generate a manufactured article including an instruction device that implements the functions specified in the Figure 1 one or more flows and / or blocks Figure 1 functions specified in one or more blocks.

[0081] These computer program instructions can also be loaded onto a computer or other programmable data processing device, such that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process, so that the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in the Figure 1 one or more flows and / or blocks Figure 1 functions specified in one or more blocks.

[0082] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: modifications or equivalent replacements can still be made to the specific embodiments of the present invention. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention shall be covered by the protection scope of the claims of the present invention.

Claims

1. A characteristic test system for parallel operation of multiple virtual synchronous generators, characterized in that The system includes: controllers corresponding to the main circuit simulation models of each virtual synchronous generator, each simulation interface, each DC source simulation model, the main circuit simulation models of each virtual synchronous generator in multi-machine parallel connection, a transformer simulation model, and a power grid simulation device. A connection point is set between the main circuit simulation models of each virtual synchronous generator in multi-machine parallel connection and the transformer simulation model; Each of the DC source simulation models is respectively connected to the main circuit simulation models of each virtual synchronous generator in multi-machine parallel connection; The main circuit simulation models of each virtual synchronous generator in multi-machine parallel connection are all connected to the power grid simulation device through the transformer simulation model; The controllers corresponding to the main circuit simulation models of each virtual synchronous generator are respectively connected to the main circuit simulation models of each virtual synchronous generator in multi-machine parallel connection through each simulation interface to perform the interaction of digital signals and analog signals; The system further includes: A single-machine type test module, configured to connect the virtual synchronous generator corresponding to a single main circuit simulation model of the main circuit simulation models of each virtual synchronous generator in multi-machine parallel connection to a pre-established single-machine type test system, and perform a single-machine type test on the virtual synchronous generator corresponding to a single main circuit simulation model; A single-machine hardware-in-the-loop test module, configured to connect a single main circuit simulation model of the main circuit simulation models of each virtual synchronous generator in multi-machine parallel connection and its corresponding controller to a pre-established single-machine hardware-in-the-loop test system, and perform a single-machine hardware-in-the-loop test on the controller corresponding to a single main circuit simulation model; An adjustment module, configured to adjust the main circuit simulation models of each virtual synchronous generator in multi-machine parallel connection respectively by using the deviation between the test results of the single-machine type test and the test results of the single-machine hardware-in-the-loop test.

2. The system according to claim 1, wherein The pre-established single-machine type test system includes: a DC source, a virtual synchronous generator corresponding to a single main circuit simulation model, a transformer, and a power grid simulation device that are connected in sequence; Wherein, a connection point is set between the virtual synchronous generator corresponding to a single main circuit simulation model and the transformer.

3. The system according to claim 2, wherein The single-machine type test module is specifically configured to: When controlling the output power of the virtual synchronous generator corresponding to a single main circuit simulation model to be maintained at 20% - 30% of the rated power through the DC source, continuously change the output frequency of the power grid simulation device, with the holding time of each output frequency being not less than 30 seconds, obtain the voltage and current at the connection point, and calculate the active power and reactive power based on the voltage and current; When controlling the output power of the virtual synchronous generator corresponding to a single main circuit simulation model to be maintained at 70% - 90% of the rated power through the DC source, continuously change the output frequency of the power grid simulation device, with the holding time of each output frequency being not less than 30 seconds, obtain the voltage and current at the connection point, and calculate the active power and reactive power based on the voltage and current; With the output power of the virtual synchronous generator corresponding to the single virtual synchronous generator main circuit simulation model controlled by the DC source maintained at 50% of the rated power, continuously change the output voltage of the power grid simulation device, with the holding time of each output voltage being not less than 30 seconds, obtain the voltage and current at the grid connection point, and calculate the active power and reactive power based on this voltage and current.

4. The system according to claim 1, wherein The pre-established single-machine hardware-in-the-loop test system includes: a controller corresponding to the single virtual synchronous generator main circuit simulation model, a simulation interface, a DC source simulation model, a single virtual synchronous generator main circuit simulation model, a transformer simulation model, and a power grid simulation device; The DC source simulation model, the single virtual synchronous generator main circuit simulation model, the transformer simulation model, and the power grid simulation device are connected in sequence; The controller corresponding to the single virtual synchronous generator main circuit simulation model is connected to the single virtual synchronous generator main circuit simulation model through the simulation interface for the interaction of digital signals and analog signals; Among them, a grid connection point is set between the single virtual synchronous generator main circuit simulation model and the transformer simulation model.

5. The system according to claim 4, wherein The single-machine hardware-in-the-loop test module is specifically used for: With the output power of the single virtual synchronous generator main circuit simulation model controlled by the DC source simulation model maintained at 20% - 30% of the rated power, continuously change the output frequency of the power grid simulation device, with the holding time of each output frequency being not less than 30 seconds, obtain the voltage and current at the grid connection point, and calculate the active power and reactive power based on this voltage and current; With the output power of the single virtual synchronous generator main circuit simulation model controlled by the DC source simulation model maintained at 70% - 90% of the rated power, continuously change the output frequency of the power grid simulation device, with the holding time of each output frequency being not less than 30 seconds, obtain the voltage and current at the grid connection point, and calculate the active power and reactive power based on this voltage and current; With the output power of the single virtual synchronous generator main circuit simulation model controlled by the DC source simulation model maintained at 50% of the rated power, continuously change the output voltage of the power grid simulation device, with the holding time of each output voltage being not less than 30 seconds, obtain the voltage and current at the grid connection point, and calculate the active power and reactive power based on this voltage and current.

6. The system according to claim 1, characterized in that, The adjustment module is specifically used for: If the deviation between the test result of the virtual synchronous generator corresponding to the single virtual synchronous generator main circuit simulation model in the pre-established single-machine type test system and the test result of the controller corresponding to the single virtual synchronous generator main circuit simulation model in the pre-established single-machine hardware-in-the-loop test system under the same operating environment is less than the preset threshold, then do not adjust the main circuit simulation models of the multiple parallel virtual synchronous generators, otherwise, adjust the inductance and capacitance in the main circuit simulation models of the multiple parallel virtual synchronous generators until the deviation is less than the preset threshold.

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