Method and device for synchronously testing multi-level frequency support performance of optical storage power station

Abstract

The invention relates to the technical field of new energy power generation, and particularly provides a multi-level frequency support performance synchronous test method and device for an optical storage power station, and the method comprises the steps: generating a frequency test signal through a pre-constructed power system frequency response model; connecting the tested optical storage power station to a pre-constructed test system, and testing the tested optical storage power station based on the frequency test signal to obtain output power and frequency at a grid connection point of the tested optical storage power station; determining a test result of the tested optical storage power station based on the output power and frequency at the grid-connected point of the tested optical storage power station; wherein the test result comprises at least one of the following: the ratio of the initial response power to the initial frequency change rate, the ratio of the response power extreme value to the frequency change extreme value, and the integral electric quantity qualified rate. According to the technical scheme provided by the invention, synchronous testing of the multi-level frequency support performance of the optical storage power station can be realized.

Description

Technical Field

[0001] The present invention relates to the field of renewable energy power generation technology, and in particular to a method and device for synchronously testing multi-level frequency support performance of a photovoltaic power station. Background Art

[0002] At present, photovoltaic power stations achieve active frequency support by configuring single-machine virtual inertia control and unit-level or station-level primary frequency regulation control. Among them, virtual inertia control is realized by simulating the synchronous machine rotor motion equation, which is a power droop control, and theoretically can achieve no delay response after power disturbance; primary frequency regulation control is realized by sending power adjustment instructions from the unit / station power controller, which is a frequency droop control, and the response lag time is generally within 1s.

[0003] At present, the test and evaluation of the frequency support performance of photovoltaic power stations is mostly carried out in a hierarchical manner through frequency step and ramp tests. This causes the test signal to deviate from the actual frequency disturbance characteristics, the test process to deviate from the actual power station frequency response control link, and the test results are difficult to characterize the inertia and primary frequency coordination capabilities in the dynamic frequency change. Summary of the invention

[0004] In order to overcome the above-mentioned defects, the present invention proposes a method and device for synchronously testing the multi-level frequency support performance of a photovoltaic power station.

[0005] In a first aspect, a method for synchronously testing the multi-level frequency support performance of a photovoltaic power station is provided, and the method for synchronously testing the multi-level frequency support performance of a photovoltaic power station comprises:

[0006] Generate frequency test signals using pre-built power system frequency response models;

[0007] Connecting the photovoltaic power station to be tested to a pre-built test system, and testing the photovoltaic power station to be tested based on the frequency test signal to obtain the output power and frequency at the grid connection point of the photovoltaic power station to be tested;

[0008] Determining a test result of the tested photovoltaic power station based on the output power and frequency at the grid connection point of the tested photovoltaic power station;

[0009] The test result includes at least one of the following: the ratio of the initial response power to the initial frequency change rate, the ratio of the response power extreme value to the frequency change extreme value, and the integrated power qualification rate.

[0010] Preferably, the pre-built power system frequency response model is as follows:

[0011]

[0012]

[0013] In the above formula, Δf is the frequency change value, ΔP L is the load active power difference, M g is the system inertia, T1 is the characteristic parameter of the turbine reheater in the first synchronous unit, t is the frequency modulation delay time of the new energy unit, a, b, c, d, f, f, A1, A2, A3, p, q, A, B, C are all intermediate variables, D g is the damping coefficient, a1 is the characteristic parameter of the turbine reheater in the second synchronous unit, R is the frequency modulation coefficient of the synchronous unit, D re is the primary frequency regulation control coefficient of the new energy power station, t is the time, and e is the natural constant.

[0014] Furthermore, the process of obtaining the system inertia and damping coefficient includes:

[0015] Obtain the frequency fluctuation data and output power fluctuation data at the power station grid connection point corresponding to the frequency regulation dead zone during the historical frequency disturbance event;

[0016] Substituting the frequency fluctuation data and the output power fluctuation data into the first objective function and solving it to obtain a system inertia identification value and a damping coefficient identification value;

[0017] The system inertia identification value and the damping coefficient identification value are used as the system inertia and the damping coefficient respectively.

[0018] Furthermore, the first objective function is as follows:

[0019] min F1=|ΔP1-(D g 'Δf1+M g 'dΔf1 / dt)|

[0020] In the above formula, F1 is the first target value, ΔP1 is the output power fluctuation data at the power station grid connection point corresponding to the frequency regulation dead zone during the historical frequency disturbance event, Δf1 is the frequency fluctuation data at the power station grid connection point corresponding to the frequency regulation dead zone during the historical frequency disturbance event, D g ' is the damping coefficient identification value, M g ' is the system inertia identification value.

[0021] Furthermore, the process of obtaining the frequency regulation coefficient of the synchronous unit and the primary frequency regulation control coefficient of the new energy power station includes:

[0022] Obtain the frequency fluctuation data and output power fluctuation data at the power station grid connection point corresponding to the frequency regulation dead zone and the frequency change rate less than 0.01Hz / s during the historical frequency disturbance event;

[0023] Substituting the frequency fluctuation data and the output power fluctuation data into the second objective function and solving it, to obtain the frequency regulation coefficient identification value of the synchronous unit and the primary frequency regulation control coefficient identification value of the new energy power station;

[0024] The frequency regulation coefficient identification value of the synchronous unit and the primary frequency regulation control coefficient identification value of the new energy power station are used as the frequency regulation coefficient of the synchronous unit and the primary frequency regulation control coefficient of the new energy power station respectively.

[0025] Furthermore, the second objective function is as follows:

[0026] min F2=|ΔP2-(D g 'Δf2+(1 / R')Δf2+D re 'Δf2)|

[0027] In the above formula, F2 is the second target value, ΔP2 is the output power fluctuation data at the power station grid connection point corresponding to the frequency change rate less than 0.01Hz / s outside the frequency regulation dead zone during the historical frequency disturbance event, and D g ' is the damping coefficient identification value, Δf2 is the frequency fluctuation data at the power station grid connection point corresponding to the frequency regulation dead zone and the frequency change rate less than 0.01Hz / s during the historical frequency disturbance event, R' is the frequency regulation coefficient identification value of the synchronous unit, D re ' is the identification value of the primary frequency regulation control coefficient of the new energy power station.

[0028] Furthermore, the process of acquiring the characteristic parameters of the turbine reheater in the first synchronous unit, the characteristic parameters of the turbine reheater in the second synchronous unit, and the frequency modulation delay time of the new energy unit includes:

[0029] Obtain the frequency fluctuation data and load active power difference at the power station grid connection point corresponding to the frequency regulation dead zone and the frequency change rate not less than 0.01Hz / s during the historical frequency disturbance event;

[0030] Substituting the frequency fluctuation data and the load active power difference into the third objective function and solving it, obtaining the turbine reheater characteristic parameter identification value in the first synchronous unit, the turbine reheater characteristic parameter identification value in the second synchronous unit and the frequency modulation delay time identification value of the new energy unit;

[0031] The characteristic parameter identification value of the turbine reheater in the first synchronous unit, the characteristic parameter identification value of the turbine reheater in the second synchronous unit and the identification value of the frequency regulation delay time of the new energy unit are respectively used as the characteristic parameter of the turbine reheater in the first synchronous unit, the characteristic parameter of the turbine reheater in the second synchronous unit and the frequency regulation delay time of the new energy unit.

[0032] Furthermore, the third objective function is as follows:

[0033] min F3=|Δf3-model(D g ',M g ',R',D re ',a1',T1',t')|

[0034] In the above formula, F3 is the third target value, Δf3 is the frequency fluctuation data at the power station grid connection point corresponding to the frequency regulation dead zone and the frequency change rate not less than 0.01Hz / s during the historical frequency disturbance event, model(D g ',M g ',R',D re ',a1',T1',t') is about (D g ',M g ',R',D re ',a1',T1',t') power system frequency response model, D g ' is the damping coefficient identification value, R' is the frequency modulation coefficient identification value of the synchronous unit, D re ' is the identification value of the primary frequency regulation control coefficient of the new energy power station, M g ' is the system inertia identification value, a1' is the turbine reheater characteristic parameter identification value in the second synchronous unit, T1' is the turbine reheater characteristic parameter identification value in the first synchronous unit, and t' is the frequency regulation delay time identification value of the new energy unit.

[0035] Preferably, the method of connecting the photovoltaic power station to be tested to a pre-built test system and testing the photovoltaic power station to be tested based on the frequency test signal to obtain the output power and frequency at the grid connection point of the photovoltaic power station to be tested includes:

[0036] Connect the photovoltaic power plant to be tested to the grid simulation source, and simultaneously connect the voltage transformer PT and current transformer CT at the grid connection point to the measurement channels of the single machine and unit / station power controller in the photovoltaic power plant to be tested;

[0037] Control the output voltage of the power grid simulation source to change according to the characteristics of the frequency test signal, and record the voltage waveform of the voltage transformer PT and the current waveform of the current transformer CT;

[0038] The output power and frequency at the grid connection point of the photovoltaic power station under test are obtained based on the voltage waveform and the current waveform.

[0039] Preferably, the method of connecting the photovoltaic power station to be tested to a pre-built test system and testing the photovoltaic power station to be tested based on the frequency test signal to obtain the output power and frequency at the grid connection point of the photovoltaic power station to be tested includes:

[0040] Connect the voltage transformer PT and current transformer CT at the grid connection point of the tested photovoltaic power station to the measurement channel of the self-synchronous test signal generator, and connect the output voltage of the test signal generator to the test channel of the single machine and unit / station power controller;

[0041] Control the output voltage of the self-synchronous test signal generator to keep synchronization with the actual grid connection point voltage;

[0042] Controlling the output voltage of the self-synchronous test signal generator to change according to the characteristics of the frequency test signal, and recording the voltage waveform of the voltage transformer PT and the current waveform of the current transformer CT;

[0043] The output power and frequency at the grid connection point of the photovoltaic power station under test are obtained based on the voltage waveform and the current waveform.

[0044] Preferably, the test results of the tested photovoltaic power station are as follows:

[0045]

[0046] In the above formula, H m is the ratio of the initial response power to the initial frequency change rate, D m E is the ratio of the response power extreme value to the frequency change extreme value. m is the integral power qualified rate, ΔP m1 , ΔP mm are the output power fluctuation value and the output power fluctuation extreme value of the measured photovoltaic power station within the initial 10ms of the frequency disturbance; Δf m1 , Δf mm are the frequency fluctuation value and frequency fluctuation extreme value of the tested photovoltaic power station within the initial 10ms of frequency disturbance; t1 and t2 are the starting and ending times of the frequency disturbance test, ΔP m is the output power fluctuation value of the measured photovoltaic power station, Δf m is the frequency fluctuation value of the measured photovoltaic power station.

[0047] In a second aspect, a multi-level frequency support performance synchronization test device for a photovoltaic power station is provided, and the multi-level frequency support performance synchronization test device for a photovoltaic power station comprises:

[0048] A simulation module for generating frequency test signals using a pre-built power system frequency response model;

[0049] A test module is used to connect the tested photovoltaic power station to a pre-built test system, and test the tested photovoltaic power station based on the frequency test signal to obtain the output power and frequency at the grid connection point of the tested photovoltaic power station;

[0050] A determination module, used to determine the test result of the tested photovoltaic power station based on the output power and frequency at the grid connection point of the tested photovoltaic power station;

[0051] The test result includes at least one of the following: the ratio of the initial response power to the initial frequency change rate, the ratio of the response power extreme value to the frequency change extreme value, and the integrated power qualification rate.

[0052] In a third aspect, a computer device is provided, comprising: one or more processors;

[0053] The processor is configured to execute one or more programs;

[0054] When the one or more programs are executed by the one or more processors, the method for synchronously testing the multi-level frequency support performance of a photovoltaic power station is implemented.

[0055] In a fourth aspect, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed, the method for synchronously testing the multi-level frequency support performance of a photovoltaic power station is implemented.

[0056] The above one or more technical solutions of the present invention have at least one or more of the following beneficial effects:

[0057] The present invention provides a method and device for synchronously testing the multi-level frequency support performance of a photovoltaic power station, including: using a pre-constructed power system frequency response model to generate a frequency test signal; connecting the photovoltaic power station to be tested to a pre-constructed test system, and testing the photovoltaic power station based on the frequency test signal to obtain the output power and frequency at the grid connection point of the photovoltaic power station; determining the test result of the photovoltaic power station based on the output power and frequency at the grid connection point of the photovoltaic power station; wherein the test result includes at least one of the following: the ratio of the initial response power to the initial frequency change rate, the ratio of the response power extreme value to the frequency change extreme value, and the integrated power qualified rate. The technical solution provided by the present invention evaluates the frequency support performance of the photovoltaic power station from three aspects: initial response power / initial frequency change rate, response power extreme value / frequency change extreme value, and integrated power, and can realize synchronous testing of the multi-level frequency support performance of the photovoltaic power station. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 This is a schematic flow chart of the main steps of a method for synchronously testing the multi-level frequency support performance of a photovoltaic power station according to an embodiment of the present invention;

[0059] Figure 2 is a sequential characteristic curve diagram of the system frequency response of an embodiment of the present invention;

[0060] Figure 3is a diagram of a test system using a power grid simulation source according to an embodiment of the present invention;

[0061] Figure 4 is a diagram of a test system using a self-synchronous test signal generator according to an embodiment of the present invention;

[0062] Figure 5 1 is a comparison diagram of an actual frequency waveform and an identified frequency waveform according to an embodiment of the present invention. DETAILED DESCRIPTION

[0063] The specific implementation modes of the present invention will be further described in detail below in conjunction with the accompanying drawings.

[0064] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are 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 creative work are within the scope of protection of the present invention.

[0065] Example 1

[0066] See attached Figure 1 , Figure 1 1 is a schematic flow chart of the main steps of a method for synchronously testing the multi-level frequency support performance of a photovoltaic power station according to an embodiment of the present invention. Figure 1 As shown, the method for synchronously testing the multi-level frequency support performance of a photovoltaic power station in an embodiment of the present invention mainly includes the following steps:

[0067] Step S101: Generate a frequency test signal using a pre-built power system frequency response model;

[0068] Step S102: connecting the photovoltaic power station to be tested to a pre-built test system, and testing the photovoltaic power station to be tested based on the frequency test signal to obtain the output power and frequency at the grid connection point of the photovoltaic power station to be tested;

[0069] Step S103: determining a test result of the tested photovoltaic power station based on the output power and frequency at the grid connection point of the tested photovoltaic power station;

[0070] The test result includes at least one of the following: the ratio of the initial response power to the initial frequency change rate, the ratio of the response power extreme value to the frequency change extreme value, and the integrated power qualification rate.

[0071] In this embodiment, the pre-built power system frequency response model is as follows:

[0072]

[0073]

[0074] In the above formula, Δf is the frequency change value, ΔP L is the load active power difference, M g is the system inertia, T1 is the characteristic parameter of the turbine reheater in the first synchronous unit, t is the frequency modulation delay time of the new energy unit, a, b, c, d, f, f, A1, A2, A3, p, q, A, B, C are all intermediate variables, D g is the damping coefficient, a1 is the characteristic parameter of the turbine reheater in the second synchronous unit, R is the frequency modulation coefficient of the synchronous unit, D re is the primary frequency regulation control coefficient of the new energy power station, t is the time, and e is the natural constant.

[0075] For the identification of multidimensional unknown parameters in the time domain model, firstly, the frequency fluctuation data Δf, output power fluctuation data ΔP and load active power difference ΔP during the historical frequency disturbance event are obtained through the online monitoring device such as the synchronous phasor measurement device PMU or recording device at the power station grid connection point. L ; Then, according to the sequential characteristics of the system frequency response, such as Figure 2 As shown in the figure, the online monitoring data is divided into three parts: the pure inertia action stage, the inertia and primary frequency modulation combined action stage and the pure primary frequency modulation stage. The division method is that the area within the frequency modulation action dead zone is the pure inertia action stage, the area outside the frequency modulation action dead zone and the frequency change rate is less than 0.01Hz / s is the pure primary frequency modulation action stage, and the area outside the frequency modulation action dead zone and the frequency change rate is not less than 0.01Hz / s is the combined action stage; finally, the gray wolf improved particle swarm PSO-GWO algorithm is used to identify the multidimensional unknown parameters step by step, that is, M is identified in the pure inertia action stage. g , D g , identify R and D in the pure primary frequency modulation stage re , a1, T1, and τ are identified in the joint action stage.

[0076] In one embodiment, the process of obtaining the system inertia and damping coefficient includes:

[0077] Obtain the frequency fluctuation data and output power fluctuation data at the power station grid connection point corresponding to the frequency regulation dead zone during the historical frequency disturbance event;

[0078] Substituting the frequency fluctuation data and the output power fluctuation data into the first objective function and solving it to obtain a system inertia identification value and a damping coefficient identification value;

[0079] The system inertia identification value and the damping coefficient identification value are used as the system inertia and the damping coefficient respectively.

[0080] In one embodiment, the first objective function is as follows:

[0081] min F1=|ΔP1-(D g 'Δf1+M g 'dΔf1 / dt)|

[0082] In the above formula, F1 is the first target value, ΔP1 is the output power fluctuation data at the power station grid connection point corresponding to the frequency regulation dead zone during the historical frequency disturbance event, Δf1 is the frequency fluctuation data at the power station grid connection point corresponding to the frequency regulation dead zone during the historical frequency disturbance event, D g ' is the damping coefficient identification value, M g ' is the system inertia identification value.

[0083] In one embodiment, the process of obtaining the frequency regulation coefficient of the synchronous unit and the primary frequency regulation control coefficient of the new energy power station includes:

[0084] Obtain the frequency fluctuation data and output power fluctuation data at the power station grid connection point corresponding to the frequency regulation dead zone and the frequency change rate less than 0.01Hz / s during the historical frequency disturbance event;

[0085] Substituting the frequency fluctuation data and the output power fluctuation data into the second objective function and solving it, to obtain the frequency regulation coefficient identification value of the synchronous unit and the primary frequency regulation control coefficient identification value of the new energy power station;

[0086] The frequency regulation coefficient identification value of the synchronous unit and the primary frequency regulation control coefficient identification value of the new energy power station are used as the frequency regulation coefficient of the synchronous unit and the primary frequency regulation control coefficient of the new energy power station respectively.

[0087] In one embodiment, the second objective function is as follows:

[0088] min F2=|ΔP2-(D g 'Δf2+(1 / R')Δf2+D re 'Δf2)|

[0089] In the above formula, F2 is the second target value, ΔP2 is the output power fluctuation data at the power station grid connection point corresponding to the frequency change rate less than 0.01Hz / s outside the frequency regulation dead zone during the historical frequency disturbance event, and D g ' is the damping coefficient identification value, Δf2 is the frequency fluctuation data at the power station grid connection point corresponding to the frequency regulation dead zone and the frequency change rate less than 0.01Hz / s during the historical frequency disturbance event, R' is the frequency regulation coefficient identification value of the synchronous unit, D re ' is the identification value of the primary frequency regulation control coefficient of the new energy power station.

[0090] In one embodiment, the process of acquiring the characteristic parameters of the turbine reheater in the first synchronous unit, the characteristic parameters of the turbine reheater in the second synchronous unit, and the frequency modulation delay time of the new energy unit includes:

[0091] Obtain the frequency fluctuation data and load active power difference at the power station grid connection point corresponding to the frequency regulation dead zone and the frequency change rate not less than 0.01Hz / s during the historical frequency disturbance event;

[0092] Substituting the frequency fluctuation data and the load active power difference into the third objective function and solving it, obtaining the turbine reheater characteristic parameter identification value in the first synchronous unit, the turbine reheater characteristic parameter identification value in the second synchronous unit and the frequency modulation delay time identification value of the new energy unit;

[0093] The characteristic parameter identification value of the turbine reheater in the first synchronous unit, the characteristic parameter identification value of the turbine reheater in the second synchronous unit and the identification value of the frequency regulation delay time of the new energy unit are respectively used as the characteristic parameter of the turbine reheater in the first synchronous unit, the characteristic parameter of the turbine reheater in the second synchronous unit and the frequency regulation delay time of the new energy unit.

[0094] In one embodiment, the third objective function is as follows:

[0095] min F3=|Δf3-model(D g ',M g ',R',D re ',a1',T1',t')

[0096] In the above formula, F3 is the third target value, Δf3 is the frequency fluctuation data at the power station grid connection point corresponding to the frequency regulation dead zone and the frequency change rate not less than 0.01Hz / s during the historical frequency disturbance event, model(D g ',M g ',R',D re ',a1',T1',t') is about (D g ',M g ',R',D re ',a1',T1',t') power system frequency response model, D g ' is the damping coefficient identification value, R' is the frequency modulation coefficient identification value of the synchronous unit, D re ' is the identification value of the primary frequency regulation control coefficient of the new energy power station, M g ' is the system inertia identification value, a1' is the turbine reheater characteristic parameter identification value in the second synchronous unit, T1' is the turbine reheater characteristic parameter identification value in the first synchronous unit, and t' is the frequency regulation delay time identification value of the new energy unit.

[0097] In this embodiment, when the power grid simulation source is used to synchronously test the single machine and unit / station power controller in the power station, the test system is as follows: Figure 3 As shown, the photovoltaic power station to be tested is connected to a pre-built test system, and the photovoltaic power station to be tested is tested based on the frequency test signal to obtain the output power and frequency at the grid connection point of the photovoltaic power station to be tested, including:

[0098] Connect the photovoltaic power plant to be tested to the grid simulation source, and simultaneously connect the voltage transformer PT and current transformer CT at the grid connection point to the measurement channels of the single machine and unit / station power controller in the photovoltaic power plant to be tested;

[0099] Control the output voltage of the power grid simulation source to change according to the characteristics of the frequency test signal, and record the voltage waveform of the voltage transformer PT and the current waveform of the current transformer CT;

[0100] The output power and frequency at the grid connection point of the photovoltaic power station under test are obtained based on the voltage waveform and the current waveform.

[0101] In this embodiment, when the self-synchronous test signal generator is used to synchronously test the single machine and unit / station power controller in the power station, the test system is as follows: Figure 4 As shown, the photovoltaic power station to be tested is connected to a pre-built test system, and the photovoltaic power station to be tested is tested based on the frequency test signal to obtain the output power and frequency at the grid connection point of the photovoltaic power station to be tested, including:

[0102] Connect the voltage transformer PT and current transformer CT at the grid connection point of the tested photovoltaic power station to the measurement channel of the self-synchronous test signal generator, and connect the output voltage of the test signal generator to the test channel of the single machine and unit / station power controller;

[0103] Control the output voltage of the self-synchronous test signal generator to keep synchronization with the actual grid connection point voltage;

[0104] Controlling the output voltage of the self-synchronous test signal generator to change according to the characteristics of the frequency test signal, and recording the voltage waveform of the voltage transformer PT and the current waveform of the current transformer CT;

[0105] The output power and frequency at the grid connection point of the photovoltaic power station under test are obtained based on the voltage waveform and the current waveform.

[0106] In this embodiment, the test results of the tested photovoltaic power station are as follows:

[0107]

[0108] In the above formula, H m is the ratio of the initial response power to the initial frequency change rate, Dm E is the ratio of the response power extreme value to the frequency change extreme value. m is the integral power qualified rate, ΔP m1 , ΔP mm are the output power fluctuation value and the output power fluctuation extreme value of the measured photovoltaic power station within the initial 10ms of the frequency disturbance; Δf m1 , Δf mm are the frequency fluctuation value and frequency fluctuation extreme value of the tested photovoltaic power station within the initial 10ms of frequency disturbance; t1 and t2 are the starting and ending times of the frequency disturbance test, ΔP m is the output power fluctuation value of the measured photovoltaic power station, Δf m is the frequency fluctuation value of the measured photovoltaic power station.

[0109] In a specific implementation, a 25MW new energy power station connected to a 100MW synchronous machine system model is built in RTLAB. A 45MW load is connected to the simulation system, and the new energy power station is configured with single-machine virtual inertia control and station-level primary frequency regulation control. The system frequency regulation control parameters are set to [M g ,D g ,a1,T1,1 / R,τ,D re ]=[6,0.1%,0.15,6,20,0.8,30].

[0110] According to the invention steps, when the system experiences a load fluctuation of 10MW, the actual frequency waveform and the identified frequency waveform are as follows: Figure 5 shown.

[0111] The load fluctuation value ΔP in the identified power system frequency response time domain model is L Set to 10% to obtain the frequency test curve. And use the self-synchronous test signal generator to perform single-machine and station-level frequency modulation performance synchronization tests. According to the original recorded frequency Δf m and power data ΔP m , the frequency support performance evaluation index value is calculated as [H m ,D m ,E m ]=[5.96,50.02,89.21%].

[0112] Example 2

[0113] Based on the same inventive concept, the present invention also provides a device for synchronously testing the multi-level frequency support performance of a photovoltaic power station, and the device for synchronously testing the multi-level frequency support performance of a photovoltaic power station comprises:

[0114] A simulation module for generating frequency test signals using a pre-built power system frequency response model;

[0115] A test module is used to connect the tested photovoltaic power station to a pre-built test system, and test the tested photovoltaic power station based on the frequency test signal to obtain the output power and frequency at the grid connection point of the tested photovoltaic power station;

[0116] A determination module, used to determine the test result of the tested photovoltaic power station based on the output power and frequency at the grid connection point of the tested photovoltaic power station;

[0117] The test result includes at least one of the following: the ratio of the initial response power to the initial frequency change rate, the ratio of the response power extreme value to the frequency change extreme value, and the integrated power qualification rate.

[0118] Preferably, the pre-built power system frequency response model is as follows:

[0119]

[0120] In the above formula, Δf is the frequency change value, ΔP L is the load active power difference, M g is the system inertia, T1 is the characteristic parameter of the turbine reheater in the first synchronous unit, t is the frequency modulation delay time of the new energy unit, a, b, c, d, f, f, A1, A2, A3, p, q, A, B, C are all intermediate variables, D g is the damping coefficient, a1 is the characteristic parameter of the turbine reheater in the second synchronous unit, R is the frequency modulation coefficient of the synchronous unit, D re is the primary frequency regulation control coefficient of the new energy power station, t is the time, and e is the natural constant.

[0121] Furthermore, the process of obtaining the system inertia and damping coefficient includes:

[0122] Obtain the frequency fluctuation data and output power fluctuation data at the power station grid connection point corresponding to the frequency regulation dead zone during the historical frequency disturbance event;

[0123] Substituting the frequency fluctuation data and the output power fluctuation data into the first objective function and solving it to obtain a system inertia identification value and a damping coefficient identification value;

[0124] The system inertia identification value and the damping coefficient identification value are used as the system inertia and the damping coefficient respectively.

[0125] Furthermore, the first objective function is as follows:

[0126] min F1=|ΔP1-(D g 'Δf1+M g 'dΔf1 / dt)|

[0127] In the above formula, F1 is the first target value, ΔP1 is the output power fluctuation data at the power station grid connection point corresponding to the frequency regulation dead zone during the historical frequency disturbance event, Δf1 is the frequency fluctuation data at the power station grid connection point corresponding to the frequency regulation dead zone during the historical frequency disturbance event, D g ' is the damping coefficient identification value, M g ' is the system inertia identification value.

[0128] Furthermore, the process of obtaining the frequency regulation coefficient of the synchronous unit and the primary frequency regulation control coefficient of the new energy power station includes:

[0129] Obtain the frequency fluctuation data and output power fluctuation data at the power station grid connection point corresponding to the frequency regulation dead zone and the frequency change rate less than 0.01Hz / s during the historical frequency disturbance event;

[0130] Substituting the frequency fluctuation data and the output power fluctuation data into the second objective function and solving it, to obtain the frequency regulation coefficient identification value of the synchronous unit and the primary frequency regulation control coefficient identification value of the new energy power station;

[0131] The frequency regulation coefficient identification value of the synchronous unit and the primary frequency regulation control coefficient identification value of the new energy power station are used as the frequency regulation coefficient of the synchronous unit and the primary frequency regulation control coefficient of the new energy power station respectively.

[0132] Furthermore, the second objective function is as follows:

[0133] min F2=|ΔP2-(D g 'Δf2+(1 / R')Δf2+D re 'Δf2)|

[0134] In the above formula, F2 is the second target value, ΔP2 is the output power fluctuation data at the power station grid connection point corresponding to the frequency change rate less than 0.01Hz / s outside the frequency regulation dead zone during the historical frequency disturbance event, and D g ' is the damping coefficient identification value, Δf2 is the frequency fluctuation data at the power station grid connection point corresponding to the frequency regulation dead zone and the frequency change rate less than 0.01Hz / s during the historical frequency disturbance event, R' is the frequency regulation coefficient identification value of the synchronous unit, D re ' is the identification value of the primary frequency regulation control coefficient of the new energy power station.

[0135] Furthermore, the process of acquiring the characteristic parameters of the turbine reheater in the first synchronous unit, the characteristic parameters of the turbine reheater in the second synchronous unit, and the frequency modulation delay time of the new energy unit includes:

[0136] Obtain the frequency fluctuation data and load active power difference at the power station grid connection point corresponding to the frequency regulation dead zone and the frequency change rate not less than 0.01Hz / s during the historical frequency disturbance event;

[0137] Substituting the frequency fluctuation data and the load active power difference into the third objective function and solving it, obtaining the turbine reheater characteristic parameter identification value in the first synchronous unit, the turbine reheater characteristic parameter identification value in the second synchronous unit and the frequency modulation delay time identification value of the new energy unit;

[0138] The characteristic parameter identification value of the turbine reheater in the first synchronous unit, the characteristic parameter identification value of the turbine reheater in the second synchronous unit and the identification value of the frequency regulation delay time of the new energy unit are respectively used as the characteristic parameter of the turbine reheater in the first synchronous unit, the characteristic parameter of the turbine reheater in the second synchronous unit and the frequency regulation delay time of the new energy unit.

[0139] Furthermore, the third objective function is as follows:

[0140] min F3=|Δf3-model(D g ',M g ',R',D re ',a1',T1',t')

[0141] In the above formula, F3 is the third target value, Δf3 is the frequency fluctuation data at the power station grid connection point corresponding to the frequency regulation dead zone and the frequency change rate not less than 0.01Hz / s during the historical frequency disturbance event, model(D g ',M g ',R',D re ',a1',T1',t') is about (D g ',M g ',R',D re ',a1',T1',t') power system frequency response model, D g ' is the damping coefficient identification value, R' is the frequency modulation coefficient identification value of the synchronous unit, D re ' is the identification value of the primary frequency regulation control coefficient of the new energy power station, M g ' is the system inertia identification value, a1' is the turbine reheater characteristic parameter identification value in the second synchronous unit, T1' is the turbine reheater characteristic parameter identification value in the first synchronous unit, and t' is the frequency regulation delay time identification value of the new energy unit.

[0142] Preferably, the method of connecting the photovoltaic power station to be tested to a pre-built test system and testing the photovoltaic power station to be tested based on the frequency test signal to obtain the output power and frequency at the grid connection point of the photovoltaic power station to be tested includes:

[0143] Connect the photovoltaic power plant to be tested to the grid simulation source, and simultaneously connect the voltage transformer PT and current transformer CT at the grid connection point to the measurement channels of the single machine and unit / station power controller in the photovoltaic power plant to be tested;

[0144] Control the output voltage of the power grid simulation source to change according to the characteristics of the frequency test signal, and record the voltage waveform of the voltage transformer PT and the current waveform of the current transformer CT;

[0145] The output power and frequency at the grid connection point of the photovoltaic power station under test are obtained based on the voltage waveform and the current waveform.

[0146] Preferably, the method of connecting the photovoltaic power station to be tested to a pre-built test system and testing the photovoltaic power station to be tested based on the frequency test signal to obtain the output power and frequency at the grid connection point of the photovoltaic power station to be tested includes:

[0147] Connect the voltage transformer PT and current transformer CT at the grid connection point of the tested photovoltaic power station to the measurement channel of the self-synchronous test signal generator, and connect the output voltage of the test signal generator to the test channel of the single machine and unit / station power controller;

[0148] Control the output voltage of the self-synchronous test signal generator to keep synchronization with the actual grid connection point voltage;

[0149] Controlling the output voltage of the self-synchronous test signal generator to change according to the characteristics of the frequency test signal, and recording the voltage waveform of the voltage transformer PT and the current waveform of the current transformer CT;

[0150] The output power and frequency at the grid connection point of the photovoltaic power station under test are obtained based on the voltage waveform and the current waveform.

[0151] Preferably, the test results of the tested photovoltaic power station are as follows:

[0152]

[0153] In the above formula, H m is the ratio of the initial response power to the initial frequency change rate, D m E is the ratio of the response power extreme value to the frequency change extreme value. m is the integral power qualified rate, ΔP m1 , ΔP mm are the output power fluctuation value and the output power fluctuation extreme value of the measured photovoltaic power station within the initial 10ms of the frequency disturbance; Δf m1 , Δf mm are the frequency fluctuation value and frequency fluctuation extreme value of the tested photovoltaic power station within the initial 10ms of frequency disturbance; t1 and t2 are the starting and ending times of the frequency disturbance test, ΔPm is the output power fluctuation value of the measured photovoltaic power station, Δf m is the frequency fluctuation value of the measured photovoltaic power station.

[0154] Example 3

[0155] Based on the same inventive concept, the present invention also provides a computer device, which includes a processor and a memory, wherein the memory is used to store a computer program, the computer program includes program instructions, and the processor is used to execute the program instructions stored in the computer storage medium. The processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. It is the computing core and control core of the terminal, which is suitable for implementing one or more instructions, and is specifically suitable for loading and executing one or more instructions in the computer storage medium to implement the corresponding method flow or corresponding function, so as to implement the steps of a method for synchronously testing the multi-level frequency support performance of a photovoltaic power station in the above embodiment.

[0156] Example 4

[0157] Based on the same inventive concept, the present invention also provides a storage medium, specifically a computer-readable storage medium (Memory), which is a memory device in a computer device for storing programs and data. It can be understood that the computer-readable storage medium here can include both built-in storage media in a computer device and, of course, extended storage media supported by the computer device. The computer-readable storage medium provides a storage space, which stores the operating system of the terminal. In addition, one or more instructions suitable for being loaded and executed by a processor are also stored in the storage space, and these instructions can be one or more computer programs (including program codes). It should be noted that the computer-readable storage medium here can be a high-speed RAM memory or a non-volatile memory, such as at least one disk memory. The processor can load and execute one or more instructions stored in the computer-readable storage medium to implement the steps of a method for synchronously testing the multi-level frequency support performance of a photovoltaic power station in the above embodiment.

[0158] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention 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.

[0159] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. 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.

[0160] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0161] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0162] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for synchronously testing the multi-level frequency support performance of a photovoltaic power station, characterized in that: The method comprises: Generate frequency test signals using pre-built power system frequency response models; Connecting the photovoltaic power station to be tested to a pre-built test system, and testing the photovoltaic power station to be tested based on the frequency test signal to obtain the output power and frequency at the grid connection point of the photovoltaic power station to be tested; Determining a test result of the tested photovoltaic power station based on the output power and frequency at the grid connection point of the tested photovoltaic power station; The test result includes at least one of the following: the ratio of the initial response power to the initial frequency change rate, the ratio of the response power extreme value to the frequency change extreme value, and the integrated power qualification rate.

2. The method according to claim 1, characterized in that The pre-built power system frequency response model is as follows: In the above formula, △f is the frequency change value, △P L is the load active power difference, M g is the system inertia, T1 is the characteristic parameter of the turbine reheater in the first synchronous unit, t is the frequency modulation delay time of the new energy unit, a, b, c, d, f, f, A1, A2, A3, p, q, A, B, C are all intermediate variables, D g is the damping coefficient, a1 is the characteristic parameter of the turbine reheater in the second synchronous unit, R is the frequency modulation coefficient of the synchronous unit, D re is the primary frequency regulation control coefficient of the new energy power station, t is the time, and e is the natural constant.

3. The method according to claim 2, characterized in that The process of obtaining the system inertia and damping coefficient includes: Obtain the frequency fluctuation data and output power fluctuation data at the power station grid connection point corresponding to the frequency regulation dead zone during the historical frequency disturbance event; Substituting the frequency fluctuation data and the output power fluctuation data into the first objective function and solving it to obtain a system inertia identification value and a damping coefficient identification value; The system inertia identification value and the damping coefficient identification value are used as the system inertia and the damping coefficient respectively.

4. The method according to claim 3, characterized in that The first objective function is as follows: min F1=|△P1-(D g '△f1+M g 'd△f1 / dt)| In the above formula, F1 is the first target value, △P1 is the output power fluctuation data at the grid connection point of the power station corresponding to the dead zone of frequency regulation during the historical frequency disturbance event, △f1 is the frequency fluctuation data at the grid connection point of the power station corresponding to the dead zone of frequency regulation during the historical frequency disturbance event, D g ' is the damping coefficient identification value, M g ' is the system inertia identification value.

5. The method according to claim 2, characterized in that The process of obtaining the frequency regulation coefficient of the synchronous unit and the primary frequency regulation control coefficient of the new energy power station includes: Obtain the frequency fluctuation data and output power fluctuation data at the power station grid connection point corresponding to the frequency regulation dead zone and the frequency change rate less than 0.01Hz / s during the historical frequency disturbance event; Substituting the frequency fluctuation data and the output power fluctuation data into the second objective function and solving it, to obtain the frequency regulation coefficient identification value of the synchronous unit and the primary frequency regulation control coefficient identification value of the new energy power station; The frequency regulation coefficient identification value of the synchronous unit and the primary frequency regulation control coefficient identification value of the new energy power station are used as the frequency regulation coefficient of the synchronous unit and the primary frequency regulation control coefficient of the new energy power station respectively.

6. The method according to claim 5, characterized in that The second objective function is as follows: min F2=|△P2-(D g '△f2+(1 / R')△f2+D re '△f2)| In the above formula, F2 is the second target value, △P2 is the output power fluctuation data at the power station grid connection point corresponding to the frequency change rate less than 0.01Hz / s outside the frequency regulation dead zone during the historical frequency disturbance event, and D g ' is the damping coefficient identification value, △f2 is the frequency fluctuation data at the power station grid connection point corresponding to the frequency regulation dead zone and the frequency change rate less than 0.01Hz / s during the historical frequency disturbance event, R' is the frequency regulation coefficient identification value of the synchronous unit, D re ' is the identification value of the primary frequency regulation control coefficient of the new energy power station.

7. The method according to claim 2, characterized in that The process of acquiring the characteristic parameters of the turbine reheater in the first synchronous unit, the characteristic parameters of the turbine reheater in the second synchronous unit, and the frequency modulation delay time of the new energy unit includes: Obtain the frequency fluctuation data and load active power difference at the power station grid connection point corresponding to the frequency regulation dead zone and the frequency change rate not less than 0.01Hz / s during the historical frequency disturbance event; Substituting the frequency fluctuation data and the load active power difference into the third objective function and solving it, obtaining the turbine reheater characteristic parameter identification value in the first synchronous unit, the turbine reheater characteristic parameter identification value in the second synchronous unit and the frequency modulation delay time identification value of the new energy unit; The characteristic parameter identification value of the turbine reheater in the first synchronous unit, the characteristic parameter identification value of the turbine reheater in the second synchronous unit and the identification value of the frequency regulation delay time of the new energy unit are respectively used as the characteristic parameter of the turbine reheater in the first synchronous unit, the characteristic parameter of the turbine reheater in the second synchronous unit and the frequency regulation delay time of the new energy unit.

8. The method according to claim 7, characterized in that The third objective function is as follows: min F3=|△f3-model(D g ',M g ',R',D re ',a1',T1',t')| In the above formula, F3 is the third target value, △f3 is the frequency fluctuation data at the power station grid connection point corresponding to the frequency regulation dead zone and the frequency change rate not less than 0.01Hz / s during the historical frequency disturbance event, model(D g ',M g ',R',D re ',a1',T1',t') is about (D g ',M g ',R',D re ',a1',T1',t') power system frequency response model, D g ' is the damping coefficient identification value, R' is the frequency modulation coefficient identification value of the synchronous unit, D re ' is the identification value of the primary frequency regulation control coefficient of the new energy power station, M g ' is the system inertia identification value, a1' is the turbine reheater characteristic parameter identification value in the second synchronous unit, T1' is the turbine reheater characteristic parameter identification value in the first synchronous unit, and t' is the frequency regulation delay time identification value of the new energy unit.

9. The method according to claim 1, characterized in that The method of connecting the photovoltaic power station to be tested to a pre-built test system and testing the photovoltaic power station to be tested based on the frequency test signal to obtain the output power and frequency at the grid connection point of the photovoltaic power station to be tested includes: Connect the photovoltaic power plant to be tested to the grid simulation source, and simultaneously connect the voltage transformer PT and current transformer CT at the grid connection point to the measurement channels of the single machine and unit / station power controller in the photovoltaic power plant to be tested; Control the output voltage of the power grid simulation source to change according to the characteristics of the frequency test signal, and record the voltage waveform of the voltage transformer PT and the current waveform of the current transformer CT; The output power and frequency at the grid connection point of the photovoltaic power station under test are obtained based on the voltage waveform and the current waveform.

10. The method according to claim 1, characterized in that The method of connecting the photovoltaic power station to be tested to a pre-built test system and testing the photovoltaic power station to be tested based on the frequency test signal to obtain the output power and frequency at the grid connection point of the photovoltaic power station to be tested includes: Connect the voltage transformer PT and current transformer CT at the grid connection point of the tested photovoltaic power station to the measurement channel of the self-synchronous test signal generator, and connect the output voltage of the test signal generator to the test channel of the single machine and unit / station power controller; Control the output voltage of the self-synchronous test signal generator to keep synchronization with the actual grid connection point voltage; Controlling the output voltage of the self-synchronous test signal generator to change according to the characteristics of the frequency test signal, and recording the voltage waveform of the voltage transformer PT and the current waveform of the current transformer CT; The output power and frequency at the grid connection point of the photovoltaic power station under test are obtained based on the voltage waveform and the current waveform.

11. The method according to claim 1, characterized in that The test results of the tested photovoltaic power station are as follows: In the above formula, H m is the ratio of the initial response power to the initial frequency change rate, D m E is the ratio of the response power extreme value to the frequency change extreme value. m is the integral power qualified rate, ΔP m1 , ΔP mm are the output power fluctuation value and the output power fluctuation extreme value of the measured photovoltaic power station within the initial 10ms of the frequency disturbance; Δf m1 , Δf mm are the frequency fluctuation value and frequency fluctuation extreme value of the tested photovoltaic power station within the initial 10ms of frequency disturbance; t1 and t2 are the starting and ending times of the frequency disturbance test, △P m is the output power fluctuation value of the measured photovoltaic power station, △f m is the frequency fluctuation value of the measured photovoltaic power station.

12. A device for synchronously testing the multi-level frequency support performance of a photovoltaic power station according to any one of claims 1 to 11, characterized in that: The device comprises: A simulation module for generating frequency test signals using a pre-built power system frequency response model; A test module is used to connect the tested photovoltaic power station to a pre-built test system, and test the tested photovoltaic power station based on the frequency test signal to obtain the output power and frequency at the grid connection point of the tested photovoltaic power station; A determination module, used to determine the test result of the tested photovoltaic power station based on the output power and frequency at the grid connection point of the tested photovoltaic power station; The test result includes at least one of the following: the ratio of the initial response power to the initial frequency change rate, the ratio of the response power extreme value to the frequency change extreme value, and the integrated power qualification rate.

13. A computer device, characterized in that: include: one or more processors; The processor is configured to execute one or more programs; When the one or more programs are executed by the one or more processors, the method for synchronously testing the multi-level frequency support performance of a photovoltaic power station as described in any one of claims 1 to 11 is implemented.

14. A computer-readable storage medium, characterized in that: A computer program is stored thereon, and when the computer program is executed, a method for synchronously testing the multi-level frequency support performance of a photovoltaic power station as described in any one of claims 1 to 11 is implemented.

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