Inertia response test method for network-forming type energy storage system

Abstract

The invention discloses a method for testing inertia response of a network-forming type energy storage system, and belongs to the field of electric energy storage system testing. The method is specifically implemented according to the following steps: step 1, before testing, quitting station AGC and primary frequency modulation control functions; step 2, respectively accessing the frequency signal generating device to the energy storage system and the data recording analyzer, setting data recording acquisition data, and setting a frequency set value and a frequency transmitting resolution of the frequency signal generating device; 3, setting the energy storage system to operate in a charging state; 4, the frequency signal generation device sends a frequency change disturbance signal, and an inertia response test is carried out; 5, setting the energy storage system to operate in a discharge state, and repeating the step 4; 6, the data recording analyzer collects voltage and current signals of the grid-connected point of the energy storage system in real time; and 7, calculating and analyzing the inertia response of the energy storage system, and comprehensively evaluating the inertia response performance of the networking type energy storage system. The inertia response performance of the energy storage system can be accurately evaluated, and the inertia response active support capability of the energy storage system can be mastered.

Description

Technical Field

[0001] The present invention belongs to the technical field of power grid detection methods, and in particular relates to an inertia response testing method for a grid-type energy storage system. Background Art

[0002] As the total installed capacity of renewable energy power generation continues to rise and renewable energy penetration increases, the relative capacity of synchronous generators, which provide inertia and damping for the power system, decreases, leading to a gradual decrease in the system's rotational inertia. Energy storage systems with self-synchronizing voltage source characteristics can actively support grid inertia, improving the compatibility of renewable energy integration with the grid and the security and stability of the grid. Therefore, mastering inertia response testing methods for grid-connected energy storage systems is a key technology in the field of grid status monitoring.

[0003] Currently, most inertia response test methods for energy storage systems are standardized and focused on current source energy storage systems. The inertia response test method for current source energy storage systems monitors the grid frequency through the site fast frequency device, calculates the frequency change rate, and transmits instructions to the site energy management platform. The energy storage system then passively accepts and executes the instructions from the energy management platform. However, the inertia response of the voltage source energy storage system does not monitor the grid frequency through the site fast frequency device, but can autonomously sense changes in the grid frequency. Therefore, the traditional inertia response test method for current source energy storage systems is no longer applicable to the inertia response test of voltage source energy storage systems. Summary of the Invention

[0004] The purpose of the present invention is to provide an inertia response test method for a grid-type energy storage system, which solves the problem that the existing inertia response test method for a current source type energy storage system is not applicable to a grid-type energy storage system.

[0005] The technical solution adopted by the present invention is a method for testing the inertia response of a grid-type energy storage system, the method comprising:

[0006] Step 1: Before testing, exit the energy storage system's automatic power generation control function and primary frequency regulation control function;

[0007] Step 2: Connect the frequency signal generator to the energy storage system and the data recorder analyzer respectively, set the data recorder analyzer to collect data, and set the frequency setting value and frequency resolution of the frequency signal generator;

[0008] Step 3: Set the energy storage system to operate in a charging state;

[0009] Step 4: The frequency signal generating device sends a frequency change disturbance signal to perform an inertia response test;

[0010] Step 5: Set the energy storage system to operate in the discharge state and repeat step 4;

[0011] Step 6: The data recorder and analyzer collects voltage and current signals of each node of the energy storage system in real time;

[0012] Step 7: Calculate and analyze the inertia response of the energy storage system, and comprehensively evaluate the inertia response performance of the grid-type energy storage system.

[0013] Furthermore, in step 2, the data collected and recorded by the data recorder and analyzer include: the sampling frequency of the data recorder and analyzer, the PT / CT ratio, and the grid voltage; PT is a voltage transformer and CT is a current transformer.

[0014] Furthermore, in step 2 and step 5, the charging and discharging power of the energy storage system are tested at a fixed point or at several points.

[0015] Furthermore, in step 6, after the data recorder analyzer completes signal acquisition, the response characteristics of the energy storage system under the frequency step disturbance are tested;

[0016] During the inertia response test, the energy storage system should maintain stable operation, the energy storage system control function should be switched to manual control, the primary frequency regulation function should be disabled, the energy storage system charging and discharging should meet all operating conditions, and the test data collected by the data recording and analysis system should cover the entire frequency fluctuation range and frequency change rate. The next test should be carried out after the station power regulation is stable.

[0017] After the frequency changes, the support power is calculated based on the frequency change rate using the following formula:

[0018]

[0019] t is time, f is the frequency of the grid connection point of the electrochemical energy storage power station, T J - Inertia time constant of electrochemical energy storage station; P N 1. Rated capacity of electrochemical energy storage power station; f N —System rated frequency, Δf—frequency change at the grid connection point of the electrochemical energy storage power station, ΔP1—active power change of the electrochemical energy storage power station;

[0020] Grid-side converter DC voltage With synchronous generator speed The dynamic characteristics of synchronization, the modulation voltage amplitude of the grid-side converter Equivalent to the magnetic flux of a synchronous wind turbine The grid-side converter represents the converter of the grid-type energy storage system; the capacitor inertia time constant H of the grid-side converter C Equivalent to the synchronous wind turbine rotor inertia time constant H J ; Synchronous wind turbine power angle δ G and rotor speed The relationship is:

[0021]

[0022] Among them, ω Bg is the reference value of the grid angular frequency, is the per-unit value of the grid angular frequency. The relationship between the grid angular frequency and the frequency f is:

[0023] ω g =2πf (2)

[0024] By detecting the rate of change of the DC voltage at each point in the energy storage system, a real-time linkage is established with the angular frequency of the grid-side converter output voltage. The corresponding power angle δ increases, thereby increasing the grid-side converter output power and maintaining a constant DC side voltage; and vice versa.

[0025] The frequency change rate K is calculated based on the frequency f:

[0026] K=df / dt (3)

[0027] When the frequency deviation of the grid-type energy storage system test point exceeds the threshold, the energy storage system is adjusted to the system's required response frequency to provide inertia response support; by testing and calculating the response characteristics of the grid-type energy storage system under frequency change disturbances, the inertia response performance of the grid-type energy storage system is evaluated.

[0028] The present invention provides a beneficial effect: the inertia response testing method for a grid-connected energy storage system utilizes a frequency signal generator to transmit a frequency setpoint signal, while a data recorder and analyzer collects voltage and current signals at the energy storage grid connection point in real time. This method then analyzes and calculates the inertia response performance, accurately assessing the energy storage system's inertia response performance and understanding its active inertia support capability. Existing testing methods, primarily using grid simulation devices, can only test a single unit. This method, however, can accurately measure the inertia support capability of an entire station. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a wiring diagram for the field test of the present invention. Figure 2 This is the field test data of the present invention. DETAILED DESCRIPTION

[0030] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0031] Example 1

[0032] The inertia response test method of the grid-type energy storage system is implemented in the following steps:

[0033] Step 1: Before testing, after obtaining consent from the power system dispatching organization, the energy storage system (EMS) will locally control and exit the primary frequency regulation control function.

[0034] Step 2: Connect the frequency signal generator to the energy storage system and the data recorder analyzer respectively, set the data recorder to collect data, set the frequency setting value of the frequency signal generator, and the frequency resolution;

[0035] Step 3: Set the energy storage system charging power to 0% P n 50%P n 、100%P n Test within the scope;

[0036] Step 4: The frequency signal generating device sends a frequency change disturbance signal to perform an inertia response test;

[0037] Step 5: Set the energy storage system discharge power to 0% P n 50%P n 、100%P n Test within the range and repeat step 4;

[0038] Step 6: The data recorder and analyzer collects voltage and current signals of the energy storage system grid connection point in real time;

[0039] Step 7: Calculate and analyze the inertia response of the grid-type energy storage system: response lag time, rise time, adjustment time and control deviation, and comprehensively evaluate the response performance of the grid-type energy storage system.

[0040] Example 2

[0041] The inertia response test method of the grid-type energy storage system is implemented in the following steps:

[0042] The inertia response test method of the grid-type energy storage system is implemented in the following steps:

[0043] Step 1: Before testing, after obtaining consent from the power system dispatching organization, the energy storage system (EMS) will locally control and exit the primary frequency regulation control function.

[0044] Step 2: Connect the frequency signal generator to the energy storage system and the data recorder analyzer respectively, set the data recorder to collect data, set the frequency setting value of the frequency signal generator, and the frequency resolution;

[0045] Step 3: Set the energy storage system charging power to 0% P n 50%P n 、100%P n Test within the scope;

[0046] Step 4: The frequency signal generating device sends a frequency change disturbance signal to perform an inertia response test;

[0047] Step 5: Set the energy storage system discharge power to 0% P n50%P n 、100%P n Test within the range and repeat step 4;

[0048] Step 6: The data recorder and analyzer collects voltage and current signals of the energy storage system grid connection point in real time;

[0049] Step 7: Calculate and analyze the inertia response of the grid-type energy storage system: response lag time, rise time, adjustment time, and control deviation, and comprehensively evaluate the response performance of the grid-type energy storage system;

[0050] In step 2, the data recorded and collected are the analyzer sampling frequency, PT / CT ratio, and grid connection point voltage amplitude;

[0051] In steps 2 and 5, the charging and discharging power of the energy storage system are tested at fixed points, or at several points.

[0052] In step 6, after signal acquisition is completed, the response characteristics (response lag time, rise time, adjustment time and control deviation) of the energy storage system under the frequency step disturbance are tested.

[0053] Example 3

[0054] The inertia response test method of the grid-type energy storage system is implemented in the following steps:

[0055] Step 1: Before testing, after obtaining consent from the power system dispatching organization, the energy storage system (EMS) will locally control and exit the primary frequency regulation control function.

[0056] Step 2: Connect the frequency signal generator to the energy storage system and the data recorder analyzer respectively, set the data recorder to collect data, set the frequency setting value of the frequency signal generator, and the frequency resolution;

[0057] Step 3: Set the energy storage system charging power to 0% P n 50%P n 、100%P n Test within the scope;

[0058] Step 4: The frequency signal generating device sends a frequency change disturbance signal to perform an inertia response test;

[0059] Step 5: Set the energy storage system discharge power to 0% P n 50%P n 、100%P n Test within the range and repeat step 4;

[0060] Step 6: The data recorder and analyzer collects voltage and current signals of the energy storage system grid connection point in real time;

[0061] Step 7: Calculate and analyze the inertia response of the grid-type energy storage system: response lag time, rise time, adjustment time, and control deviation, and comprehensively evaluate the response performance of the grid-type energy storage system;

[0062] Among them, when conducting inertia response tests, the energy storage system should maintain stable operation, the energy storage system control function should be switched to manual control, the inertia response function should be exited, the energy storage system charging and discharging should meet all working conditions, and the test data collected by the control system should cover the frequency fluctuation range and frequency change rate. The next test should be carried out after the station power regulation is stable.

[0063] Example 4

[0064] The inertia response test method of the grid-type energy storage system is implemented in the following steps:

[0065] Step 1: Before testing, after obtaining consent from the power system dispatching organization, the energy storage system (EMS) will locally control and exit the primary frequency regulation control function.

[0066] Step 2: Connect the frequency signal generator to the energy storage system and the data recorder analyzer respectively, set the data recorder to collect data, set the frequency setting value of the frequency signal generator, and the frequency resolution;

[0067] Step 3: Set the energy storage system charging power to 0% P n 50%P n 、100%P n Test within the scope;

[0068] Step 4: The frequency signal generating device sends a frequency change disturbance signal to perform an inertia response test;

[0069] Step 5: Set the energy storage system discharge power to 0% P n 50%P n 、100%P n Test within the range and repeat step 4;

[0070] Step 6: The data recorder and analyzer collects voltage and current signals of the energy storage system grid connection point in real time;

[0071] Step 7: Calculate and analyze the inertia response of the grid-type energy storage system: response lag time, rise time, adjustment time, and control deviation, and comprehensively evaluate the response performance of the grid-type energy storage system;

[0072] Among them, the DC side voltage of the grid-side converter is With synchronous generator speed Similar dynamic characteristics, the modulation voltage amplitude of the grid-side converter It can be compared to the magnetic flux of a synchronous generator The capacitor inertia time constant H of the converter C Analogous to the synchronous generator rotor inertia time constant H J . Synchronous generator power angle δ G About rotor speed The relationship can be expressed as:

[0073]

[0074] Among them, ω Bg is the reference value of the grid angular frequency, is the per-unit value of the grid angular frequency. The relationship between the grid angular frequency and the frequency f is:

[0075] ω g =2πf (2)

[0076] By detecting the rate of change of the DC voltage, a real-time linkage is established with the angular frequency of the grid-side converter output voltage. The corresponding power angle δ increases, thereby increasing the grid-side converter output power and maintaining a constant DC side voltage; and vice versa.

[0077] The frequency change rate K can be expressed as:

[0078] K=df / dt (3).

[0079] Example 5

[0080] The inertia response test method of the grid-type energy storage system is implemented in the following steps:

[0081] Step 1: Before testing, after obtaining consent from the power system dispatching organization, the energy storage system EMS local control is activated and the inertia response control function is exited.

[0082] Step 2: Connect the frequency signal generator to the energy storage system and the data recorder analyzer respectively, set the data recorder to collect data, set the frequency setting value of the frequency signal generator, and the frequency resolution;

[0083] Step 3: Set the energy storage system charging power to 0% P n 50%P n 、100%P n Test within the scope;

[0084] Step 4: The frequency signal generating device sends a frequency change disturbance signal to perform an inertia response test;

[0085] Step 5: Set the energy storage system discharge power to 0% P n 50%P n 、100%P n Test within the range and repeat step 4;

[0086] Step 6: The data recorder and analyzer collects voltage and current signals of the energy storage system grid connection point in real time;

[0087] Step 7: Calculate and analyze the inertia response of the grid-type energy storage system: response lag time, rise time, adjustment time, and control deviation, and comprehensively evaluate the response performance of the grid-type energy storage system;

[0088] Among them, when the frequency deviation of the test point of the grid-type energy storage system exceeds the threshold, the energy storage system should be able to respond to the change of the system frequency and provide inertia response support; by testing and calculating and analyzing the response characteristics of the grid-type energy storage system under frequency change disturbances, the inertia response performance of the grid-type energy storage system is comprehensively evaluated.

[0089] Example 6

[0090] Inertia response test method for grid-type energy storage system:

[0091] The inertia response test content of the grid-type energy storage system should be completed in the field test under the corresponding working conditions. The test conditions are as follows:

[0092] The inertia response test conditions of the grid-type energy storage system are:

[0093] (1) The power of the grid-type energy storage system is set at 0%P n For working condition 1;

[0094] (2) The grid-type energy storage system sets the charging power at 50% P n For working condition 2;

[0095] (3) The grid-type energy storage system sets the discharge power at 50% P n It is working condition 3;

[0096] (4) The grid-type energy storage system sets the charging power at 100% P n It is working condition 4;

[0097] (5) The grid-type energy storage system sets the discharge power at 100% P n It is working condition 5;

[0098] On-site test wiring Figure 1 As shown in FIG, a grid-type energy storage system inertia response test is implemented in the following steps:

[0099] Step 1: Obtain consent from the power system dispatching organization to which it belongs, and the energy storage system EMS local control and exit the inertia response control function;

[0100] Step 2: The frequency signal generating device sends a frequency change disturbance signal to perform an inertia response test to test the response characteristics of the grid-type energy storage system under the frequency change disturbance.

[0101] The frequency change disturbance test contents include 50Hz~49.8Hz, 50Hz~50.2Hz;

[0102] (1) The change from 50Hz to 48Hz is from 50Hz to 48Hz, and it lasts for 20s after reaching the set value, and then returns to 50Hz. The energy storage system is tested under working conditions 1, 2, 3, and 4 respectively;

[0103] (2) The change from 50Hz to 50.2Hz is from 50Hz to 50.2Hz, and it lasts for 20s after reaching the set value, and then returns to 50Hz. The energy storage system is tested under working conditions 1, 2, 3, and 5 respectively;

[0104] Step 3: The data recorder and analyzer collects the voltage and current signals of the grid-connected point of the grid-connected energy storage system in real time; and tests the response characteristics (response lag time, rise time, adjustment time, and control deviation) of the grid-connected energy storage system under frequency change disturbance.

[0105] Step 4: Calculate and analyze the inertia response capability of the grid-type energy storage system: response lag time, rise time, adjustment time and control deviation, and comprehensively evaluate the response performance of the grid-type energy storage system.

[0106] The inertia response testing method for a grid-type energy storage system of the present invention can transmit a frequency set value signal through a frequency signal generating device, and a data recording and analyzing instrument can collect signals such as voltage and current at the grid connection point of the energy storage system in real time, analyze and calculate the inertia response performance, accurately evaluate the inertia response performance of the grid-type energy storage system, and understand the inertia response support capability of the energy storage.

Claims

1. A method for testing inertia response of a grid-type energy storage system, the method comprising: Step 1: Before testing, exit the energy storage system's automatic power generation control function and primary frequency regulation control function; Step 2: Connect the frequency signal generator to the energy storage system and the data recorder analyzer respectively, set the data recorder analyzer to collect data, and set the frequency setting value and frequency resolution of the frequency signal generator; Step 3: Set the energy storage system to operate in a charging state; Step 4: The frequency signal generating device sends a frequency change disturbance signal to perform an inertia response test; Step 5: Set the energy storage system to operate in the discharge state and repeat step 4; Step 6: The data recorder and analyzer collects voltage and current signals of each node of the energy storage system in real time; Step 7: Calculate and analyze the inertia response of the energy storage system, and comprehensively evaluate the inertia response performance of the grid-type energy storage system.

2. A method for testing inertia response of a grid-type energy storage system according to claim 1, characterized in that: In step 2, the data collected and recorded by the data recorder and analyzer include: the sampling frequency of the data recorder and analyzer, the PT / CT ratio, and the grid voltage; PT is a voltage transformer and CT is a current transformer.

3. A method for testing inertia response of a grid-type energy storage system according to claim 1, characterized in that: In step 2 and step 5, the charging and discharging power of the energy storage system are tested at a fixed point, or at several points.

4. A method for testing inertia response of a grid-type energy storage system according to claim 1, characterized in that: In step 6, after the data recorder analyzer completes signal acquisition, the response characteristics of the energy storage system under the frequency step disturbance are tested; During the inertia response test, the energy storage system should maintain stable operation, the energy storage system control function should be switched to manual control, the primary frequency regulation function should be disabled, the energy storage system charging and discharging should meet all operating conditions, and the test data collected by the data recording and analysis system should cover the entire frequency fluctuation range and frequency change rate. The next test should be carried out after the station power regulation is stable. After the frequency changes, the support power is calculated based on the frequency change rate using the following formula: t is time, f is the frequency of the grid connection point of the electrochemical energy storage power station, T J - Inertia time constant of electrochemical energy storage station; P N 1. Rated capacity of electrochemical energy storage power station; f N —System rated frequency, Δf—frequency change at the grid connection point of the electrochemical energy storage power station, ΔP1—active power change of the electrochemical energy storage power station; Grid-side converter DC voltage With synchronous generator speed The dynamic characteristics of synchronization, the modulation voltage amplitude of the grid-side converter Equivalent to the magnetic flux of a synchronous wind turbine The grid-side converter represents the converter of the grid-type energy storage system; the capacitor inertia time constant H of the grid-side converter C Equivalent to the synchronous wind turbine rotor inertia time constant H J ; Synchronous wind turbine power angle δ G and rotor speed The relationship is: Among them, ω Bg is the reference value of the grid angular frequency, is the per-unit value of the grid angular frequency. The relationship between the grid angular frequency and the frequency f is: oh g =2πf (2) By detecting the rate of change of the DC voltage at each point in the energy storage system, a real-time linkage is established with the angular frequency of the grid-side converter output voltage. The corresponding power angle δ increases, thereby increasing the grid-side converter output power and maintaining a constant DC side voltage; and vice versa. The frequency change rate K is calculated based on the frequency f: K=df / dt (3) When the frequency deviation of the grid-type energy storage system test point exceeds the threshold, the energy storage system is adjusted to the system's required response frequency to provide inertia response support; by testing and calculating the response characteristics of the grid-type energy storage system under frequency change disturbances, the inertia response performance of the grid-type energy storage system is evaluated.

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