Energy storage controller integrated test method

Abstract

The present application relates to the technical field of energy storage controller simulation test, and discloses an energy storage controller integrated test method, which comprises the following steps: dividing the structure of multiple energy storage systems, integrating the same type of energy storage functional units to establish an energy storage power loop model library and a control structure model library, and integrating the test working conditions of the energy storage systems to establish a test working condition library; determining the structure parameters of the energy storage system corresponding to the to-be-tested energy storage controller, and calling the model library to establish a semi-physical simulation model; setting a signal interface and defining an interactive signal to establish a semi-physical simulation platform; calling the test working condition library according to the test requirements, performing semi-physical simulation test in the semi-physical simulation platform, and collecting test data. The above method adopts semi-physical simulation technology, divides the structure framework of the energy storage system, establishes a functional model library, and establishes a test working condition library, and through program calling, the whole process of energy storage controller from modeling to testing can be automatically realized in an integrated manner.

Description

Technical Field

[0001] This invention relates to the field of energy storage controller simulation testing technology, and in particular to an integrated testing method for energy storage controllers. Background Technology

[0002] With the rapid development of new energy power generation such as photovoltaic and wind power, and considering the inherent randomness and intermittency of these new energy sources, energy storage systems of a certain capacity are usually installed to support the stable operation of the power grid. As new energy sources are connected to the grid on a large scale, the energy storage capacity of these supporting systems is constantly increasing, and their applications are becoming more widespread. For example, when new energy power generation is high, energy storage systems can absorb energy that the load side cannot temporarily absorb; while when new energy power generation is insufficient or stops, they can provide necessary power support to the load side. Therefore, energy storage systems need to have good grid connection performance to adapt to this two-way regulation requirement. At the same time, problems arising from the connection of energy storage systems to the grid via power electronic converters are gradually becoming apparent.

[0003] Evaluating the performance of energy storage systems in high-proportion renewable energy power systems hinges on the effective testing of their controllers and control strategies. However, conducting on-site grid-connected tests in actual energy storage power plants is often costly and constrained by factors such as daily operational needs, site limitations, and safety considerations, making such tests difficult to conduct frequently. Conversely, relying solely on pure digital simulation for control strategy testing, while reducing costs and risks, ignores the complexity and uncertainty of the real hardware environment, potentially leading to significant deviations between simulation results and actual conditions, thus affecting the practical reference value of the test results. Summary of the Invention

[0004] In view of this, this application provides an integrated testing method for energy storage controllers, the main purpose of which is to solve the technical problems in the prior art where the conditions for conducting pure physical testing of energy storage controllers are limited and the test results obtained by pure digital simulation are inaccurate.

[0005] The integrated testing method for energy storage controllers provided by this invention includes:

[0006] Based on the type of energy storage technology, multiple energy storage systems are structurally divided to obtain multiple energy storage functional units. Energy storage functional units of the same type are integrated to establish multiple functional model libraries, and the test conditions of the multiple energy storage systems are integrated to establish a test condition library. The functional model library includes an energy storage power loop model library and a control structure model library.

[0007] Determine the initial energy storage system corresponding to the energy storage controller under test, obtain the structural parameters of the initial energy storage system, call the initial energy storage power loop model in the energy storage power loop model library based on the structural parameters, and call the initial control structure in the control structure model library to form a control loop. Establish a hardware-in-the-loop simulation model based on the initial energy storage power model and the control loop.

[0008] Set the signal interface of the hardware-in-the-loop simulation model and define the interaction signals to establish a hardware-in-the-loop simulation platform;

[0009] According to the test requirements, a target test condition is selected from the test condition library. Based on the target test condition, a hardware-in-the-loop simulation test is performed on the energy storage controller under test in the hardware-in-the-loop simulation platform, and test data is collected.

[0010] Optionally, the energy storage power circuit model library includes energy storage battery modules, converter modules, DC bus capacitors, grid-connected contactor modules, and filter circuit modules;

[0011] The energy storage battery module includes lithium-ion battery modules, lithium iron phosphate batteries, lead-acid batteries, nickel-cadmium batteries, and nickel-metal hydride batteries.

[0012] The converter module includes a three-phase bridge inverter module and a neutral-point clamped three-level inverter module;

[0013] The filtering circuit module includes an L-filtering circuit module, an LC-filtering circuit module, and an LCL-filtering circuit module.

[0014] Optionally, the control structure model library includes a current control loop module, a voltage control loop module, a power control loop module, a frequency control loop module, and a fault ride-through control module.

[0015] Optionally, selecting the target test condition from the test condition library according to test requirements includes:

[0016] According to the test requirements, select multiple initial test conditions from the test condition library, combine the multiple initial test conditions to form a target test condition, and load the target test condition into a preset test condition template for saving.

[0017] Optionally, the test condition library includes a frequency small disturbance test module, a low voltage ride-through test module, a high voltage ride-through test module, and a high and low voltage interlock ride-through test module.

[0018] The frequency small disturbance test module includes a first switching switch and a resistive load. The first switching switch is used to simulate the fluctuation of the power grid within a preset frequency range, and the resistive load is used to adjust the amplitude and range of the power grid frequency fluctuation.

[0019] The low voltage ride-through test module includes a second switching switch and a grounding impedance. The second switching switch is used to generate a voltage drop, and the grounding impedance is used to adjust the range of the voltage drop.

[0020] The high voltage ride-through test module includes a third switching switch and a capacitor. The third switching switch is used to generate a voltage rise, and the capacitor is used to adjust the range of the voltage rise.

[0021] The high and low voltage interlocking ride-through test module includes a high voltage ride-through test module and a low voltage ride-through test module.

[0022] Optionally, the step of calling the initial control structure from the control structure model library to form a control loop includes:

[0023] The initial control structure is called from the control structure model library, wherein the initial control structure is a double closed-loop control structure;

[0024] In the voltage outer loop of the dual closed-loop control structure, obtain the d-axis current reference value and the q-axis voltage component of the energy storage converter, as well as the d-axis voltage component and the q-axis voltage component of the energy storage converter in the current outer loop of the dual closed-loop control structure.

[0025] The active power and reactive power output of the energy storage converter are calculated based on the d-axis current reference value, the d-axis voltage component, and the q-axis voltage component.

[0026] Optionally, the hardware-in-the-loop simulation model includes a CPU model of the energy storage converter and an eHS model of the energy storage converter;

[0027] The energy storage converter CPU model is used for analog signal interaction, command issuance, and signal acquisition.

[0028] The energy storage converter eHS model is used to simulate the power electronic circuits of an energy storage system.

[0029] Optionally, the energy storage converter CPU model specifically includes an eHS solution module, an analog signal configuration module, a digital signal configuration module, an electrical quantity calculation module, and a signal recording module. The eHS solution module is used to call the model in the energy storage power circuit model library during the semi-physical simulation test to complete the signal interaction between the small-step simulation of the energy storage converter eHS model and the large-step simulation of the energy storage converter CPU model.

[0030] Optionally, the interactive signals include energy storage converter drive signals, grid-connected contactor drive signals, grid-connected contactor flag signals, grid voltage, DC voltage, filter current, and energy storage converter voltage and current.

[0031] Optionally, the method further includes:

[0032] Save the test data;

[0033] The test data is preprocessed, and based on preset waveform types and graphic parameters, the preprocessed test data is plotted using preset graphic drawing tools to generate a test waveform diagram.

[0034] The integrated testing method for energy storage controllers provided by this invention specifically applies hardware-in-the-loop (HIL) simulation technology, effectively combining the advantages of pure digital model simulation and pure physical testing. It enables efficient and safe testing under conditions that more closely resemble the real-time operating state of the controlled object, simplifying testing conditions and ensuring the accuracy of test results. Compared with existing conventional modeling methods, this application divides the structural framework of different energy storage systems according to energy storage technology types, dividing different energy storage systems into multiple independent but structurally interconnected energy storage functional units. These similar energy storage functional units are integrated to form energy storage power loop model libraries and control structure model libraries, making the modeling process structured. During modeling, models in the functional model libraries can be called to achieve rapid combination of various different energy storage systems, enabling faster and more efficient energy storage system modeling. Furthermore, this application integrates the test conditions of energy storage systems, establishing a test condition library and standardizing and encapsulating existing test conditions. During testing, only the required target test condition needs to be called to automatically complete the test. The encapsulation method of test conditions is also scalable, facilitating the conduct of other grid-connected tests. In summary, this application adopts hardware-in-the-loop simulation technology, divides the energy storage system into structural frameworks, establishes a functional model library, and establishes a test condition library. Through program calls, the energy storage controller can achieve integrated automatic implementation of the entire process from modeling to testing.

[0035] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, specific embodiments of this application are given below. Attached Figure Description

[0036] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0037] Figure 1 A flowchart illustrating the integrated testing method for energy storage controllers provided in an embodiment of the present invention is shown.

[0038] Figure 2This invention illustrates a schematic diagram of the energy storage system in the integrated testing method for energy storage controllers provided in an embodiment of the invention.

[0039] Figure 3 This invention illustrates a schematic diagram of the structure of the initial energy storage power loop model in the integrated testing method for energy storage controllers provided in this embodiment.

[0040] Figure 4 This diagram illustrates the process of calling an initial control structure to form a control loop in the integrated testing method for energy storage controllers provided in an embodiment of the present invention.

[0041] Figure 5 The figure shows the AC test terminal voltage waveform of the energy storage converter under the condition of low voltage ride-through voltage drop to 50% in the integrated test method for energy storage controller provided in the embodiment of the present invention.

[0042] Figure 6 The figure shows the AC test terminal voltage waveform of the energy storage converter under the condition of low voltage ride-through voltage drop to 50% in the integrated test method for energy storage controller provided in the embodiment of the present invention.

[0043] Figure 7 The diagram shows the AC active power waveform of the energy storage converter under the condition of low voltage ride-through voltage drop to 50% in the integrated test method for energy storage controller provided in this embodiment of the invention.

[0044] Figure 8 The figure shows the AC test terminal reactive power waveform of the energy storage converter under the condition of low voltage ride-through voltage drop to 50% in the integrated test method for energy storage controller provided in the embodiment of the present invention.

[0045] Figure 9 The diagram shows the AC terminal voltage waveform of the energy storage converter under the condition of high voltage ride-through voltage rise to 120% in the integrated energy storage controller testing method provided in this embodiment of the invention.

[0046] Figure 10 The diagram shows the AC terminal current waveform of the energy storage converter under the condition of high voltage ride-through voltage rise to 120% in the integrated energy storage controller testing method provided in this embodiment of the invention.

[0047] Figure 11 The diagram shows the AC active power waveform of the energy storage converter under the condition of high voltage ride-through voltage rise to 120% in the integrated test method for energy storage controller provided in this embodiment of the invention.

[0048] Figure 12 The diagram illustrates the reactive power waveform at the AC test terminal of the energy storage converter under the condition of high voltage ride-through voltage rise to 120% in the integrated test method for energy storage controller provided in this embodiment of the invention. Detailed Implementation

[0049] Exemplary embodiments of the present application will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present application are shown in the drawings, it should be understood that the present application may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this application will be thorough and complete, and will fully convey the scope of the present application to those skilled in the art.

[0050] This application introduces the background of the technical solution provided. In the prior art, on-site testing of grid-connected performance at energy storage power stations is costly, slow in modeling, and inefficient, and carries certain risks during testing under extreme conditions. While offline testing of grid-connected performance of energy storage systems using pure digital simulation suffers from insufficient computing power and hardware limitations, resulting in discrepancies between simulation and actual test results, making it difficult to provide effective reference for the stable grid-connected operation of actual energy storage systems. Therefore, this application proposes the technical solution to address the shortcomings of the aforementioned traditional testing methods.

[0051] This invention provides an integrated testing method for energy storage controllers, such as... Figure 1 As shown, firstly, multiple energy storage systems are structurally divided based on energy storage technology types, resulting in multiple energy storage functional units. These functional units of the same type are integrated to establish multiple functional model libraries, and the test conditions of multiple energy storage systems are integrated to establish a test condition library. The functional model libraries include an energy storage power loop model library and a control structure model library. Next, the initial energy storage system corresponding to the energy storage controller under test is determined, and its structural parameters are obtained. Based on these parameters, the initial energy storage power loop model is called from the energy storage power loop model library, and the initial control structure is called from the control structure model library to form a control loop. A hardware-in-the-loop (HIL) simulation model is then established based on the initial energy storage power model and the control loop. Afterward, the signal interface of the HIL simulation model is set, and interactive signals are defined to establish a HIL simulation platform. Finally, according to the test requirements, a target test condition is selected from the test condition library. Based on the target test condition, a HIL simulation test is performed on the energy storage controller under test within the HIL simulation platform, and test data is collected.

[0052] The integrated testing method for energy storage controllers provided by this invention specifically applies hardware-in-the-loop (HIL) simulation technology, effectively combining the advantages of pure digital model simulation and pure physical testing. It enables efficient and safe testing under conditions that more closely resemble the real-time operating state of the controlled object, simplifying testing conditions and ensuring the accuracy of test results. Compared with existing conventional modeling methods, this application divides the structural framework of different energy storage systems according to energy storage technology types, dividing different energy storage systems into multiple independent but structurally interconnected energy storage functional units. These similar energy storage functional units are integrated to form energy storage power loop model libraries and control structure model libraries, making the modeling process structured. During modeling, models in the functional model libraries can be called to achieve rapid combination of various different energy storage systems, enabling faster and more efficient energy storage system modeling. Furthermore, this application integrates the test conditions of energy storage systems, establishing a test condition library and standardizing and encapsulating existing test conditions. During testing, only the required target test condition needs to be called to automatically complete the test. The encapsulation method of test conditions is also scalable, facilitating the conduct of other grid-connected tests. In summary, this application adopts hardware-in-the-loop simulation technology, divides the energy storage system into structural frameworks, establishes a functional model library, and establishes a test condition library. Through program calls, the energy storage controller can achieve integrated automatic implementation of the entire process from modeling to testing.

[0053] Specifically, in the above embodiments, the energy storage power circuit model library includes an energy storage battery module, a converter module, a DC bus capacitor, a grid-connected contactor module, and a filter circuit module; wherein, the energy storage battery module includes a lithium-ion battery module, a lithium iron phosphate battery, a lead-acid battery, a nickel-cadmium battery, and a nickel-metal hydride battery; the converter module includes a three-phase bridge inverter module and a neutral-point clamped three-level inverter module; the filter circuit module includes an L filter circuit module, an LC filter circuit module, and an LCL filter circuit module.

[0054] In this embodiment, different types of energy storage systems are first analyzed. Key components of the energy storage system are identified from their structural mechanisms and divided into multiple energy storage functional units, such as... Figure 2 As shown, a schematic diagram of a specific energy storage system is presented, including a battery, inverter circuit, filter, and AC contactor. Energy storage functional units with the same function or characteristics are then categorized to form an energy storage power loop model library and a control structure model library. The energy storage power loop model library, according to functional type, can specifically include various functional modules such as energy storage battery modules, converter modules, DC bus capacitors, grid-connected contactor modules, and filter circuit modules. The energy storage battery module, converter module, and filter circuit module can be further divided into multiple modules; for example... Figure 3As shown, a specific energy storage power circuit model is presented, which includes a simulated grid input module for calling grid signals from the CPU model; an AC contactor module for simulating the contactor control when the energy storage system is connected to or disconnected from the grid; a filter module for filtering the AC side voltage and current of the converter; a converter module for inverting DC power from the battery side to AC power; a voltage stabilizing capacitor module for stabilizing the DC side voltage; and a battery input signal module for calling battery signals from the CPU model.

[0055] Specifically, in the above embodiments, the control structure model library includes a current control loop module, a voltage control loop module, a power control loop module, a frequency control loop module, and a fault ride-through control module.

[0056] In this embodiment, the control structure model library also includes a variety of different functional modules. The current control loop module is for precisely controlling the output current of the energy storage converter; the voltage control loop module is for maintaining the DC bus voltage or AC side voltage at the desired level; the power control loop module is for controlling the exchange of active and reactive power between the energy storage system and the grid; the frequency control loop module is for maintaining grid frequency stability; and the fault ride-through control module is for ensuring that the energy storage system can operate safely and stably during grid faults.

[0057] Specifically, in the above embodiments, calling an initial control structure from the control structure model library to form a control loop includes first calling an initial control structure from the control structure model library, wherein the initial control structure is a double closed-loop control structure; then obtaining the d-axis current reference value and the d-axis current reference value of the energy storage converter in the voltage outer loop of the double closed-loop control structure, and the d-axis voltage component and q-axis voltage component of the energy storage converter in the current outer loop of the double closed-loop control structure; finally, calculating the active power and reactive power output by the energy storage converter based on the d-axis current reference value, the d-axis current reference value, the d-axis voltage component, and the q-axis voltage component.

[0058] In this embodiment, such as Figure 4The diagram shows a control loop. The energy storage converter controller specifically adopts a dual closed-loop structure. The outer loop is the voltage loop. After measuring the DC-side voltage Udc from the circuit, it is compared with the set reference value Udc_ref. After passing through the first proportional-integral (PI) regulator, the output obtains the d-axis current reference value idg_ref, which is then output to the inner current loop. The first PI regulator includes a proportional gain Kp_dc and an integral gain Ki_dc. In the inner current loop, the d-axis current reference value idg_ref is compared with the actual d-axis current idg before being input to the second PI regulator. At this time, the second PI regulator includes a proportional gain Kp_id and an integral gain Ki_id. The output of the second PI regulator is compensated by the cross-coupling term ωp11Lgiqg+us to obtain the grid current. The d-axis component of the voltage is Udg; for inverters operating at unity power factor, the q-axis current reference value iqg_ref is generally set to 0. The three-phase current measured from the circuit is transformed by Parker to obtain iqg, which is compared with the q-axis current reference value iqg_ref and then sent to the third proportional-integral regulator. The third proportional-integral regulator includes a proportional gain Kp_iq and an integral gain Ki_iq. The output of the third proportional-integral regulator is compensated by the cross-coupling term ωsLgiqg to obtain the q-axis component Uqg of the grid voltage. The q-axis component Uqg and the d-axis component Udg of the grid voltage are then transformed by Parker to output the three-phase voltage reference value of the energy storage converter. Finally, the gate control signal is output through the pulse width modulation stage. After each part is composed, the semi-physical simulation model of the energy storage system is automatically established.

[0059] To quickly automate the control system, a mathematical mechanism model of the control system is used for modeling. The general mathematical expression of the energy storage control system, which is composed of the energy storage system control structure model, is as follows:

[0060] Firstly, in the voltage outer loop of the dual closed-loop control, the d-axis and q-axis current reference values ​​idg_ref and iqg_ref of the energy storage converter are:

[0061]

[0062] Where Kp5 and Ki5 are the proportional and integral coefficients of the voltage controller for the energy storage converter, respectively; Udc and Udc_ref are the DC bus voltage and its reference value, respectively.

[0063] The energy storage converter uses grid voltage-oriented vector control. Given uds = us and uqs = 0, the d-axis component udg and q-axis component uqg of the energy storage converter voltage in the inner current loop of the dual closed-loop control are:

[0064]

[0065] In the formula, Kp6 and Ki6 are the proportional and integral coefficients of the d-axis current inner loop of the energy storage converter, respectively; Kp7 and Ki7 are the proportional and integral coefficients of the q-axis current inner loop of the energy storage converter, respectively; idg and iqg are the d-axis and q-axis components of the output current of the energy storage converter, respectively; Lg is the inductance of the grid-side filter; and us is the grid voltage.

[0066] Therefore, under the corresponding dual closed-loop control, the output active power Pg and reactive power Qg of the energy storage converter can be calculated as follows:

[0067]

[0068] Specifically, the target test condition is selected from the test condition library according to the test requirements. This includes selecting multiple initial test conditions from the test condition library according to the test requirements, combining the multiple initial test conditions to form the target test condition, and loading the target test condition into a preset test condition template for saving.

[0069] Furthermore, the test condition library includes a frequency small disturbance test module, a low voltage ride-through test module, a high voltage ride-through test module, and a high-low voltage interlock ride-through test module. The frequency small disturbance test module includes a first switching switch and a resistive load. The first switching switch is used to simulate the fluctuation of the power grid within a preset frequency range, and the resistive load is used to adjust the amplitude and range of the power grid frequency fluctuation. The low voltage ride-through test module includes a second switching switch and a grounding impedance. The second switching switch is used to generate a voltage drop, and the grounding impedance is used to adjust the range of the voltage drop. The high voltage ride-through test module includes a third switching switch and a capacitor. The third switching switch is used to generate a voltage rise, and the capacitor is used to adjust the range of the voltage rise. The high-low voltage interlock ride-through test module includes both a high voltage ride-through test module and a low voltage ride-through test module.

[0070] In this embodiment, the frequency small disturbance test module specifically includes a controllable first switching switch and a resistive load of a certain size. The first switching switch controls the switching of the resistive load to achieve frequency disturbance around 50Hz, and the resistive load value is adjustable within the frequency disturbance range. The low voltage ride-through test module consists of a controllable second switching switch and a grounding impedance of a certain size. When the second switching switch is engaged, the system experiences a ground short circuit, resulting in a voltage drop. The grounding impedance value is adjustable within the voltage drop range. The high voltage ride-through test module consists of a controllable third switching switch and a capacitor of a certain size. When the third switching switch is engaged, the system experiences a voltage rise. The capacitor value is adjustable within the voltage rise range. The high / low voltage interlock ride-through test module is a superposition of the low voltage ride-through test module and the high voltage ride-through test module.

[0071] Specifically, in the above embodiments, the hardware-in-the-loop simulation model includes an energy storage converter CPU model and an energy storage converter eHS model; the energy storage converter CPU model is used for analog signal interaction, command issuance, and signal acquisition; the energy storage converter eHS model is used to simulate the power electronic circuit of the energy storage system.

[0072] Furthermore, the energy storage converter CPU model specifically includes an eHS solution module, an analog signal configuration module, a digital signal configuration module, an electrical quantity calculation module, and a signal recording module. Among them, the eHS solution module is used to call the model in the energy storage power loop model library during the semi-physical simulation test to complete the signal interaction between the small step simulation of the energy storage converter eHS model and the large step simulation of the energy storage converter CPU model.

[0073] In this embodiment, two main models of the energy storage converter in the hardware-in-the-loop simulation model are provided: the CPU model and the eHS (electric Hardware-in-the-Loop Solver) model. The CPU model of the energy storage converter is used to simulate the microprocessor unit in the actual controller, responsible for handling tasks such as control algorithms, signal acquisition, and command issuance. The eHS solution module calls models from the energy storage power loop model library during the hardware-in-the-loop simulation test to realize signal interaction between small-step and large-step simulations. The analog signal configuration module is used to configure and manage the input and output of analog signals; the digital signal configuration module is used to configure and manage the input and output of digital signals; the electrical quantity calculation module is used to calculate and process various electrical quantities, such as voltage, current, and power; and the signal recording module is used to record key signal data during the simulation process. The eHS model of the energy storage converter is used to simulate the power electronic circuits of the energy storage system, including components such as inverters, filters, and transformers. This application, by setting up the eHS solution module, enables efficient data exchange between small-step and large-step simulations, ensuring the real-time performance and accuracy of the entire system.

[0074] Specifically, in the above embodiments, the interactive signals include energy storage converter drive signals, grid-connected contactor drive signals, grid-connected contactor flag signals, grid voltage, DC voltage, filter current, and energy storage converter voltage and current.

[0075] In this embodiment, based on the automatically generated hardware-in-the-loop simulation model, it is necessary to automatically program the digital and analog signal interface sequence and set up signal interaction. Signal interaction is the key to ensuring the accuracy and real-time performance of the simulation. The interaction signals specifically include various types of control signals, status signals, and measurement signals. The interaction between the signals can simulate the actual operation of the energy storage system more accurately.

[0076] Furthermore, after collecting the test data, the test data is saved; then the test data is preprocessed, and based on the preset waveform type and graphic parameters, the preprocessed test data is plotted using the preset graphic drawing tool to generate a test waveform diagram.

[0077] In this implementation, the collected test data is organized and saved for subsequent analysis and archiving. Then, the program automatically generates test waveforms to visually display the test results. First, a suitable drawing tool needs to be selected, and the type of waveform to be drawn needs to be determined, such as voltage waveform, current waveform, power waveform, etc. Then, the graphic parameters are set: the title, axis labels, legend, color, line style, etc. are configured to ensure that the graphic is clear and readable. Finally, the drawing script is run to generate waveforms for all test conditions in batches.

[0078] Based on the integrated testing method for energy storage controllers provided in this application, the fault voltage ride-through test of the energy storage controller is used as an example to illustrate its correctness.

[0079] During the test, the operating conditions are set, and the low voltage ride-through test module is automatically invoked to make the grid voltage drop to 50% for a duration of about 625ms. Then the grid voltage quickly recovers to the rated value. The dynamic characteristic curve during this process will be automatically collected and saved. Figure 5 The automatically generated AC test terminal voltage waveform of the energy storage converter under the condition of low voltage ride-through voltage drop to 50% shows that the low voltage ride-through test module successfully pulled the voltage down to 50% of the rated value. Figure 6 The automatically generated AC terminal current waveform of the energy storage converter under the condition of low voltage ride-through voltage drop to 50%; Figure 7 The automatically generated active power waveform at the AC test terminal of the energy storage converter under the condition of low voltage ride-through voltage drop to 50%; Figure 8 This is the automatically generated AC reactive power waveform at the machine terminal of the energy storage converter under low-voltage ride-through voltage drop to 50%. Figure 5 , Figure 6 , Figure 7 and Figure 8 From 6.5s to 7.0s, it can be seen that the energy storage converter can operate in steady state connected to the grid. However, at approximately 7.25s, due to the connection of the grounding impedance, the grid voltage is momentarily pulled down to 0.5pu. At this time, the active power decreases instantaneously, and the reactive power increases instantaneously to support the system. At 7.9s, the fault is cleared, the voltage returns to normal, the reactive power recovers instantaneously, and the active power recovers in a sloped manner. Figure 9 The automatically generated AC terminal voltage waveform of the energy storage converter under the condition of high voltage ride-through voltage rise to 120%; Figure 10The automatically generated AC terminal current waveform of the energy storage converter under the condition of high voltage ride-through voltage rise to 120%; Figure 11 The AC active power waveform at the test terminal of the automatically generated energy storage converter under the condition of high voltage ride-through voltage rise to 120%; Figure 12 The waveform of reactive power at the AC test terminal of the energy storage converter is automatically generated under the condition of high voltage ride-through voltage rise to 120%. The high voltage ride-through test is similar to the low voltage ride-through test and will not be described further here. In summary, based on the test results, the integrated energy storage controller testing method provided in this application can efficiently and automatically verify the effectiveness of grid-connected energy storage tests on actual energy storage controllers.

Claims

1. An integrated testing method for energy storage controllers, characterized in that, The method comprises the following steps: based on the type of energy storage technology, the plurality of energy storage systems are structurally divided to obtain a plurality of energy storage functional units, the same type of energy storage functional units are integrated to establish a plurality of functional model libraries, and the test conditions of the plurality of energy storage systems are integrated to establish a test condition library, wherein the functional model library comprises a power loop model library and a control structure model library, and the test condition library comprises a small frequency disturbance test module for simulating grid frequency disturbance, a low voltage ride through test module for simulating voltage drop, and a high voltage ride through test module for simulating voltage rise; determine the initial energy storage system corresponding to the to-be-tested energy storage controller, obtain the structural parameters of the initial energy storage system, call the initial energy storage power loop model in the energy storage power loop model library based on the structural parameters, and call the initial control structure in the control structure model library to form a control link, and establish a semi-physical simulation model based on the initial energy storage power loop model and the control link, wherein the semi-physical simulation model comprises an energy storage converter CPU model and an energy storage converter eHS model, the energy storage converter CPU model is used for analog signal interaction, command issuing and signal acquisition, and the energy storage converter eHS model is used for simulating the power electronic circuit of the energy storage system; set the signal interface of the semi-physical simulation model and define the interaction signal to establish a semi-physical simulation platform; select a target test condition in the test condition library according to the test requirement, and perform semi-physical simulation test on the to-be-tested energy storage controller in the semi-physical simulation platform based on the target test condition and collect test data; the target test condition in the test condition library according to the test requirement, comprising: select a plurality of initial test conditions in the test condition library according to the test requirement, combine the plurality of initial test conditions to form a target test condition, and load the target test condition into a preset test condition template for saving; the initial control structure in the control structure model library to form a control link, comprising: call the initial control structure in the control structure model library, wherein the initial control structure is a double closed loop control structure; obtain the d-axis current reference value and the d-axis current reference value of the energy storage converter in the voltage outer loop of the double closed loop control structure, and obtain the d-axis voltage component and the q-axis voltage component of the energy storage converter in the current outer loop of the double closed loop control structure; according to the d-axis current reference value, the d-axis current reference value, the d-axis voltage component and the q-axis voltage component, the active power and the reactive power output by the energy storage converter are calculated.

2. The method of claim 1, wherein, The energy storage power loop model library comprises an energy storage battery module, a converter module, a DC bus capacitor, a grid-connected contactor module and a filter circuit module; The energy storage battery module comprises a lithium ion battery module, a lithium iron phosphate battery, a lead-acid battery, a nickel-cadmium battery and a nickel-hydrogen battery; The converter module comprises a three-phase bridge inverter module and a neutral point clamped three-level inverter module; The filter circuit module comprises an L filter circuit module, an LC filter circuit module and an LCL filter circuit module.

3. The method of claim 1, wherein, The control structure model library comprises a current control loop module, a voltage control loop module, a power control loop module, a frequency control loop module and a fault ride-through control module.

4. The method of claim 1, wherein, The test working condition library further comprises a high-low voltage interlocking ride-through test module; The frequency small disturbance test module comprises a first switching switch and a resistance load, the first switching switch is used for simulating the condition that the power grid fluctuates in a preset frequency range, and the resistance load is used for adjusting the amplitude and range of the power grid frequency fluctuation. The low voltage ride-through test module comprises a second switching switch and a grounding impedance, the second switching switch is used for forming voltage drop, and the grounding impedance is used for adjusting the range of voltage drop. The high voltage ride-through test module comprises a third switching switch and a capacitor, the third switching switch is used for forming voltage rise, and the capacitor is used for adjusting the range of voltage rise. The high-low voltage interlocking ride-through test module comprises the high voltage ride-through test module and the low voltage ride-through test module.

5. The method of claim 1, wherein, The energy storage converter CPU model specifically comprises an eHS solving module, an analog signal configuration module, a digital signal configuration module, an electrical quantity calculation module and a signal recording module, wherein the eHS solving module is used for calling the model in the energy storage power loop model library in the process of performing the semi-physical simulation test, so as to complete the signal interaction between the small step simulation of the energy storage converter eHS model and the large step simulation of the energy storage converter CPU model.

6. The method of claim 1, wherein, The interaction signal comprises an energy storage converter driving signal, a grid-connected contactor driving signal, a grid-connected contactor flag signal, a power grid voltage, a direct current voltage, a filter current and an energy storage converter voltage and current.

7. The method of claim 1, wherein, The method further comprises: saving the test data; preprocessing the test data, based on preset waveform types and graphic parameters, using a preset graphic drawing tool to draw the preprocessed test data, and generating a test waveform diagram.

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