A power decoupling type working condition simulation test system and method of a battery energy storage module

Abstract

The application provides a power decoupling type working condition simulation test system and method of a battery energy storage module, and the system comprises: a test circuit, which comprises: a current shaper, a battery energy storage module to be tested, and a filter; the current shaper is composed of an active current shaping unit and a reactive current shaping unit in series or parallel relationship, actively controls and shapes the test current covering the active-reactive four-quadrant of the measured object; the AC port of the battery energy storage module to be tested is connected in series with the current shaper and the filter in turn to form a closed-loop test loop; a current shaper controller controls the power decoupling and the DC voltage stability; a measured controller receives the test instruction of the simulated real energy storage system, generates and controls the drive signal of the battery energy storage module to be tested. The application realizes the transient and steady state full operation condition test covering the active-reactive four-quadrant operation range, reduces the test cost, actively balances the transient energy, and has high transient condition test capability.

Description

Technical Field

[0001] This application relates to the field of energy storage system testing technology, specifically to a power decoupling type operating condition simulation test system and method for battery energy storage modules. Background Technology

[0002] With the development of new power systems, battery energy storage systems need to possess four-quadrant active and reactive power operation capabilities to provide flexible grid support. However, complex operating conditions and frequent cross-quadrant power switching can easily cause fluctuations in the electrothermal stress of internal components of battery energy storage modules, leading to reliability issues. Currently, system-level testing of complete energy storage systems is costly and extremely difficult to implement. The industry often uses traditional parallel testing circuits at the module unit level for verification. However, traditional parallel testing methods are limited by the voltage modulation capability of the test unit, facing a severely limited test power range and failing to cover the extreme operating boundaries of the entire active-reactive four-quadrant system.

[0003] In the prior art, application number CN202211689781.0 discloses a testing system and method for energy storage submodules of high-voltage direct-connected energy storage equipment, including: a current generator, which generates a test current using a cascaded full-bridge structure, and reduces the harmonic content of the current generator's output voltage based on carrier phase shifting or carrier stacking modulation; an energy storage submodule under test; a current controller, used to control the current generator and thus adjust the test current; a submodule controller, used to control the energy storage submodule under test and thus adjust the submodule's state of charge and voltage; and an energy storage system parameter model, used to output reference signals for current control and state of charge control to the current controller and submodule controller, respectively. The above technical solution does not distinguish between active current units and reactive current units, and cannot cover the extreme operating boundaries of the entire active-reactive four-quadrant system.

[0004] Furthermore, the compromise in filter inductor parameters to expand the power testing range, coupled with the low switching frequency of the module itself, results in severe distortion of the test current in traditional drag-and-drop testing, extremely low accuracy of operating condition reproduction, and poor dynamic response under large disturbance step conditions such as cross-quadrant switching, making it difficult to accurately assess the true electrothermal characteristics and transient tolerance of the battery energy storage module under test.

[0005] Therefore, there is an urgent need for a testing method that can simulate the complex operating conditions of battery energy storage modules at low cost and with high accuracy. Summary of the Invention

[0006] In view of one of the defects in the prior art, the purpose of this application is to provide a power decoupled operating condition simulation test system for battery energy storage modules.

[0007] A first aspect of this application provides a power decoupling-type operating condition simulation test system for a battery energy storage module, comprising: The test circuit includes a current shaper, a battery energy storage module under test, and a filter. The current shaper is composed of an active current shaping unit and a reactive current shaping unit connected in series or parallel, used to actively control and shape a test current covering the active and reactive four quadrants of the tested object. The AC port of the battery energy storage module under test is connected in series with the current shaper and the filter to form a closed-loop test circuit, used to receive the test current and drive signal consistent with actual operating conditions. The filter is connected in series in the closed-loop test circuit to reduce the ripple rate of the test current. The current shaping controller decouples the total reference current required for testing into mutually orthogonal active current component commands and reactive current component commands, and controls the active current shaping unit and the reactive current shaping unit to output corresponding currents to follow the commands, while simultaneously stabilizing the DC voltage. The controller under test receives test commands simulating a real energy storage system, generates and controls the drive signals of the battery energy storage module under test to make it match the actual operating conditions.

[0008] Optionally, the converters in the active current shaping unit and the reactive current shaping unit are both H-bridge converters or half-bridge converters. The reactive current shaping unit is configured as a unidirectional power supply to handle the test reactive power. The unidirectional power supply is a unidirectional DC voltage source or a DC regulated power supply with a unidirectional diode connected in series. The unidirectional diode is used to block the energy reverse feedback path. The active current shaping unit is configured as a bidirectional power supply with bidirectional power flow capability to handle the tested active power. The bidirectional power source is a battery pack or a bidirectional DC voltage source, which has bidirectional power flow capability and is used to actively absorb transient unbalanced energy during testing.

[0009] Optionally, the battery energy storage module under test includes an H-bridge converter under test, an interface circuit, and a battery cluster; The DC side of the H-bridge converter under test is connected in parallel with the battery cluster via the interface circuit, and the AC side of the H-bridge converter under test is connected to the test circuit to receive the test current.

[0010] Optionally, when generating the drive signal, the controller under test converts the reference signal into a drive signal under test using a sinusoidal pulse width modulation method based on the modulation voltage reference signal that is the same as the actual operating conditions; the drive signal under test controls the switching state of the converter circuit in the battery energy storage module under test.

[0011] Optionally, the filter is an L-type filter, an LC-type filter, or an LCL-type filter; the location and number of the filters are determined according to the connection method of each unit in the current shaper. When the active current shaping unit and the reactive current shaping unit are connected in series, a filter is set at any position in the test circuit. When the active current shaping unit and the reactive current shaping unit are connected in parallel, the filter includes a total filter connected in series in the main circuit of the test circuit, and branch filters that are independently connected in series in the active current shaping unit and the reactive current shaping unit, respectively.

[0012] Optionally, the current shaper controller controls the current shaper in multiple operating modes, including: pure active test mode, pure reactive test mode, mixed active and reactive test mode, and independent charging and discharging mode of active shaping unit; In the pure active power test mode, under pure active power operation conditions, the active power required for the test is entirely borne by the active current shaping unit, and the output active power of the reactive current shaping unit is near zero. In the pure reactive power test mode, under the pure reactive power operation condition, the AC current required for the test is mainly provided by the reactive current shaping unit, the output current of the active current shaping unit is controlled near zero, and the active power of both the active current shaping unit and the reactive current shaping unit is near zero. In the active and reactive power mixed test mode, under the active and reactive power mixed operation condition, the active current shaping unit and the reactive current shaping unit respectively dominate the active and reactive components of the test current, and independently undertake and decouple the active and reactive power. The independent charging and discharging mode of the active current shaping unit controls the bypass operation of the battery storage module under test when the active current shaping unit needs to replenish or consume energy separately, so that the reactive current shaping unit and the active current shaping unit form a counter-carrying structure to replenish or consume energy for the active current shaping unit.

[0013] Optionally, the current shaper controller, through a feedforward and active closed-loop composite control method, decouples the total reference current required for testing into mutually orthogonal active current component commands and reactive current component commands, specifically including: Based on the test power command of the battery energy storage module under test, the initial decoupling phase angle is calculated as the feedforward quantity; The average active power of the reactive current shaping unit is sampled in real time for a single cycle, and the phase angle compensation is output through a proportional-integral controller. The final decoupling phase angle is obtained by superimposing the feedforward amount and the phase angle compensation amount, and the final decoupling phase angle is synthesized with the test current amplitude reference command by trigonometric function. The test current amplitude reference command is decomposed into the active current component command and the reactive current component command that are orthogonal to each other. The magnitude of the decomposed active current component command is proportional to the cosine of the final decoupling phase angle, and the magnitude of the reactive current component command is proportional to the sine of the final decoupling phase angle.

[0014] Optionally, the current shaper controller calculates the initial decoupling phase angle based on the test power command of the battery storage module under test, including: Based on the positive and negative active quadrants and positive and negative reactive quadrants where the test power of the battery energy storage module under test is located, determine the quadrant where the target power factor angle is located; Based on the phasor angle between the test current and the AC port voltage of the battery energy storage module under test, the amplitude of the test current, the amplitude of the AC port voltage, and the filter inductor parameters, the phase shift caused by the filter inductor is calculated. The initial decoupling phase angle is obtained analytically by using the phasor superposition relationship.

[0015] Optionally, the current shaping controller operates through active DC voltage stabilization control and current closed-loop control, respectively controlling the active current shaping unit and the reactive current shaping unit to output corresponding currents to follow the command, specifically including: The DC-side voltage deviation of the reactive current shaping unit is used to generate a compensation current command via a proportional-integral controller or a proportional controller. The compensation current command is positively superimposed onto the reference command of the reactive current component, and at the same time, the compensation current command of equal value and opposite direction is superimposed onto the reference command of the active current component, so that the active current shaping unit actively absorbs unbalanced energy. A proportional-integral-resonant controller is used to enable the actual current of the active current shaping unit and the reactive current shaping unit to track the fundamental frequency sinusoidal current command, generate the modulation voltage of the active current shaping unit and the reactive current shaping unit, and generate the drive signal of the active current shaping unit and the reactive current shaping unit using a sinusoidal pulse width modulation method.

[0016] A second aspect of this application provides a power decoupling-type operating condition simulation test method for a battery energy storage module, comprising: The total current required for the test is decoupled into active current component and reactive current component by the current shaping controller, and the active current shaping unit and reactive current shaping unit are controlled to output the corresponding current respectively to achieve power decoupling and DC voltage stabilization. The drive signal of the battery energy storage module under test is generated and controlled by the controller under test to make it match the actual operating conditions.

[0017] This application provides a power decoupled operating condition simulation test system for battery energy storage modules. It employs a combination of test circuitry and a current shaper controller. Through a power decoupling architecture and active current control, it eliminates the need for a complete energy storage system and expensive high-power bidirectional power supplies. The reactive power unit can meet testing requirements with only a unidirectional power supply, significantly reducing hardware costs and testing difficulty. Simultaneously, it breaks through the power range limitations of traditional testing, fully covering the active-reactive four-quadrant operating boundary. Combined with closed-loop current control and filter design, it reduces test current distortion and ripple rate, improves operating condition reproduction accuracy and dynamic response capability, and actively balances transient unbalanced energy. This allows for accurate assessment of the actual electrothermal characteristics and transient tolerance of the module under test. It changes the traditional open-loop mode that relies on voltage difference to indirectly generate current, using a current shaper controller for composite closed-loop control of the test current, significantly reducing test current distortion and simulation errors under steady-state operating conditions.

[0018] Other technical effects resulting from the additional features will be further illustrated in the corresponding embodiments. Attached Figure Description

[0019] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 This is a schematic diagram of the topology and control architecture of a power decoupling type operating condition simulation test system for a battery energy storage module provided in one embodiment of the present invention; Figure 2 This is a schematic diagram of the topology and control architecture of a power decoupling type operating condition simulation test system for another battery energy storage module provided in one embodiment of the present invention; Figure 3 This is a schematic diagram of the topology of the battery energy storage module / module group under test in the power decoupling type operating condition simulation test system of the battery energy storage module provided in one embodiment of the present invention. Figure 4 This is a flowchart of a power decoupling type operating condition simulation test method for a battery energy storage module provided in one embodiment of the present invention.

[0020] In the diagram, 1. Parallel test circuit; 2. Series test circuit; 3. Current shaper controller; 4. Controller under test; 5. Current shaper; 6. Battery energy storage module under test; 7. Filter; 51. Reactive current shaping unit; 52. Active current shaping unit; 61. H-bridge converter under test; 62. Interface circuit; 63. Battery cluster. Detailed Implementation

[0021] The present application will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present application, but do not limit the present application in any way. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present application, and these all fall within the protection scope of the present application. Parts not described in detail in the following embodiments can be implemented using existing technology.

[0022] In the description of the embodiments of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0023] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature.

[0024] In the description of the embodiments in this application, "multiple" means two or more, unless otherwise explicitly specified. In this application, unless otherwise explicitly specified and limited, the terms "installed," "connected," "linked," "fixed," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0025] The terms "comprising" and "having," and any variations thereof, in the embodiments of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such processes, methods, products, or devices.

[0026] In existing technologies, compromises are made on filter inductor parameters to expand the power testing range. Combined with the low switching frequency of the module itself, this results in severe distortion of the test current in traditional parallel-drive tests, extremely low accuracy in reproducing operating conditions, and poor dynamic response under large disturbance step conditions such as quadrant switching. Consequently, it is difficult to accurately assess the true electrothermal characteristics and transient withstand capability of the battery energy storage module under test. To address these issues, this application provides a power decoupled operating condition simulation test system for battery energy storage modules to resolve these problems.

[0027] Reference Figure 1 or Figure 2 As shown in one embodiment of this application, a power decoupling type operating condition simulation test system for a battery energy storage module includes: a test circuit (including a parallel test circuit 1 and a series test circuit 2), a current shaper controller 3, and a controller under test 4.

[0028] The test circuit includes a current shaper 5, a battery energy storage module 6 under test, and a filter 7. The current shaper 5 is composed of an active current shaping unit 52 and a reactive current shaping unit 51 connected in series or parallel, and is used to actively control and shape the test current covering the four quadrants of active and reactive power of the test object. The AC port of the battery energy storage module 6 under test is connected in series with the current shaper 5 and the filter 7 to form a closed-loop test circuit, which is used to receive the test current and drive signal that match the actual operating conditions. The filter 7 is connected in series in the closed-loop test circuit to reduce the ripple rate of the test current. The current shaping controller 3 is used to decouple the total reference current required for the test into mutually orthogonal active current component commands and reactive current component commands, and respectively control the active current shaping unit 52 and reactive current shaping unit 51 to output the corresponding current to follow the commands, while simultaneously stabilizing the DC voltage; the controller under test 4 is used to receive the test commands simulating the real energy storage system, generate and control the drive signal of the battery energy storage module 6 under test, so that it matches the actual operating conditions.

[0029] Specifically, firstly, the active current shaping unit 52 and reactive current shaping unit 51 in the current shaping device 5 are connected in series or parallel, and then connected in series with the battery energy storage module 6 under test and the filter 7 to form a closed-loop test circuit. Subsequently, the current shaping device controller 3 receives the total current command required for the test, and decouples it into mutually orthogonal active current components and reactive current components through a combination of feedforward and closed-loop control. It then outputs corresponding current reference commands to the active current shaping unit 52 (configured with bidirectional power supply) and the reactive current shaping unit 51 (configured with unidirectional power supply), respectively. The two units actively shape the active current according to the commands. The test current is used for the reactive four-quadrant operating range. At the same time, the total reference current required for the test is actively decoupled into mutually orthogonal active current component commands and reactive current component commands through the current shaping controller 3. The active current shaping unit 52, which is composed of bidirectional power supply, and the reactive current shaping unit 51, which is composed of unidirectional power supply, are controlled to output the corresponding currents, so that the active current shaping unit 52 actively absorbs transient unbalanced energy and maintains DC voltage stability. The controller under test 4 generates a drive signal that matches the actual operating conditions according to the test command of the simulated real energy storage system, and controls the battery energy storage module 6 under test to perform corresponding charging, discharging or power regulation actions, thereby realizing the performance test of the energy storage module under steady-state and transient operating conditions in the closed loop.

[0030] In the embodiments described above, the test current is actively decoupled into active and reactive components, which are then independently handled by the active current shaping unit 52 (configured with a bidirectional power supply) and the reactive current shaping unit 51 (configured with a unidirectional power supply). This allows the reactive current shaping unit 51 to meet the full power range testing requirements with only a low-cost unidirectional DC power supply, eliminating the need for an expensive high-power bidirectional power supply. While reducing the reactive power four-quadrant operating boundary, it also reduced hardware costs; it changed the traditional open-loop mode of indirectly generating current by relying on voltage difference, and used the current shaper controller 3 to perform composite closed-loop control of the test current, which improved the test current distortion rate and simulation error under steady-state conditions.

[0031] Among them, the battery energy storage module 6 under test can also be a group of battery energy storage modules under test; when the active current shaping unit 52 and the reactive current shaping unit 51 are connected in parallel, the test circuit is a parallel test circuit 1, such as Figure 1 As shown, specifically, the current shaper controller 3 first acquires the AC voltage sampling signal from the parallel output port of the current shaper. The total test current command is decoupled into mutually orthogonal active current component reference commands through a feedforward and active closed-loop composite control algorithm. and reactive current component reference command The corresponding drive signals are generated and sent to the active current shaping unit 52 and reactive current shaping unit 51 in the current shaping unit 5, respectively; the active current shaping unit 52 is configured with a bidirectional power supply. The output current carries all active power and transient unbalanced energy. The reactive current shaping unit 51 (configured with a unidirectional power supply) is based on... The output reactive current independently handles all reactive power. The two currents are superimposed at the parallel node to form the total test current, which then flows through the filter 7 connected in series in the main circuit to filter out switching harmonics and reduce current ripple. Finally, it is sent to the AC port of the battery energy storage module 6 or module group under test to form a closed-loop test circuit. At the same time, the controller under test 4 receives the reference modulation voltage command simulating the operation of a real energy storage system. It generates a drive signal consistent with the actual operating conditions through sinusoidal pulse width modulation and sends it to the battery energy storage module or module group 6 under test to control the switching state of its internal converter. This accurately reproduces the steady-state and transient operating conditions in the active-reactive four-quadrant range and completes the performance test of the module under test.

[0032] When the active current shaping unit 52 and the reactive current shaping unit 51 are connected in series, the test circuit is a series-type test circuit 2, such as... Figure 2 As shown, the current shaping controller 3 first acquires the AC voltage sampling signal from the output port of the reactive current shaping unit 51 in the series branch. A unified total test current command is generated through a combined feedforward and active power closed-loop control algorithm. Based on power decoupling logic, the current is converted into voltage reference commands for the active current shaping unit 52 and the reactive current shaping unit 51, respectively. Then, corresponding drive signals are generated and sent to the active current shaping unit 52 and the reactive current shaping unit 51 connected in series within the current shaping unit 5. Since the two shaping units are connected in series, the current flowing through them is exactly the same. The active current shaping unit 52 (configured with a bidirectional power supply) outputs a voltage component that is in phase / out of phase with the loop current to bear all active power and transient unbalanced energy. The reactive current shaping unit 51 (configured with a unidirectional power supply) outputs a voltage component that is orthogonal to the loop current to independently bear all reactive power. The output voltages of the two units are superimposed to form the total test voltage, which drives the closed loop to generate a unified total test current. The current flows through the filter 7 connected in series in the main circuit to filter out switching harmonics and reduce current ripple before being sent to the AC port of the battery energy storage module 6 or module group under test. At the same time, the controller under test 4 receives the reference modulation voltage command simulating the operation of a real energy storage system, generates a drive signal consistent with the actual operating conditions through sinusoidal pulse width modulation, and sends it to the battery energy storage module 6 or module group under test to control the switching state of its internal converter, accurately reproduce the steady-state and transient operating conditions in the active-reactive four-quadrant range, and complete the performance test of the module under test.

[0033] It's important to note that the difference between series and parallel topologies lies in how power decoupling is achieved: series topologies use voltage component decoupling (the two units have the same current and superimposed voltage), while parallel topologies use current component decoupling (the two units have the same voltage and superimposed current). Furthermore, series topologies only require one filter at any point in the main circuit to meet filtering requirements, eliminating the need for additional branch filters, resulting in a simpler hardware structure. Parallel topologies, in addition to the main circuit filter, typically require branch filters in each of the two shaping unit branches to suppress circulating current. Additionally, in a series topology, the rated current of the two shaping units must match the maximum test current of the module under test (DUT), while in a parallel topology, the rated current of the two shaping units can be independently designed based on their respective power components, making it more suitable for high-current testing scenarios. Series topologies are more suitable for testing high-voltage, low-to-medium current battery storage modules.

[0034] In some specific embodiments of this application, the converters in the active current shaping unit 52 and the reactive current shaping unit 51 are both H-bridge converters or half-bridge converters; the reactive current shaping unit 51 is configured as a unidirectional power supply to bear the test reactive power; the unidirectional power supply is a unidirectional DC voltage source or a DC regulated power supply with a unidirectional diode in series, and the unidirectional diode is used to block the energy reverse feedback path; the active current shaping unit 52 is configured as a bidirectional power supply with bidirectional power flow capability to bear the test active power; the bidirectional power supply is a battery pack or a bidirectional DC voltage source with bidirectional power flow capability to actively absorb transient unbalanced energy during testing.

[0035] Specifically, in the current shaping unit 5, the reactive current shaping unit 51 includes a first converter and a first DC-side power supply. The first converter is an H-bridge converter or a half-bridge converter, and the first DC-side power supply is a unidirectional DC voltage source or a DC regulated power supply with a unidirectional diode connected in series. The reactive current shaping unit 51 is used to provide the reactive power required for the test, and the unidirectional diode is used to block the reverse feedback path of energy. The active current shaping unit 52 includes a second converter and a second DC-side power supply. The second converter is an H-bridge converter or a half-bridge converter, and the second DC-side power supply is a battery pack or a bidirectional DC voltage source with bidirectional power flow capability. The active current shaping unit 52 is used to provide the active power required for the test and actively absorbs transient unbalanced energy during the test. Thus, under the coordination of the current shaping unit controller, the active and reactive components of the test current are output independently and accurately.

[0036] In the above embodiments of this application, by configuring the reactive current shaping unit 51 to require only a unidirectional DC voltage source or a DC regulated power supply with a unidirectional diode, it independently undertakes all reactive power, avoiding dependence on expensive high-power bidirectional power supplies and reducing the hardware cost of the test system. At the same time, the active current shaping unit 52 adopts a battery pack or a bidirectional DC voltage source, which can not only undertake the active power required for testing, but also actively absorb unbalanced energy under conditions such as cross-quadrant switching and large disturbance transients, preventing DC side voltage rise or instability, and improving the system's transient testing capability and operational safety. Combined with the fact that both units adopt H-bridge or half-bridge converters, the test system has good AC waveform modulation capability. Combined with the decoupling control of the current shaping controller, accurate output of active and reactive current is achieved, ensuring low distortion rate and high operating condition reproduction accuracy of the test current.

[0037] Reference Figure 3 As shown, in some specific embodiments of this application, the battery energy storage module 6 under test includes an H-bridge converter 61 under test, an interface circuit 62, and a battery cluster 63.

[0038] The DC side of the H-bridge converter under test 61 is connected in parallel with the battery cluster 63 via the interface circuit 62, and the AC side of the H-bridge converter under test 61 is connected to the test circuit to receive the test current.

[0039] Specifically, the battery energy storage module 6 under test adopts a standardized combination structure of the H-bridge converter 61 under test, interface circuit 62, and battery cluster 63. The AC side of the H-bridge converter 61 under test is directly connected to the closed-loop test circuit composed of current shaper 5 and filter 7, receiving the active-reactive four-quadrant test current generated after power decoupling. Its DC side is connected in parallel with the battery cluster 63 through interface circuit 62, realizing bidirectional charging and discharging conversion of electrical energy between the AC test circuit and the DC battery cluster. Interface circuit 62 also undertakes electrical isolation, overcurrent and overvoltage protection, and impedance matching functions; no modifications to existing engineering are required. The hardware topology of the energy storage module can be directly connected for testing with any modification, making it highly versatile. The topology of the H-bridge converter 61 under test is consistent with that of the energy storage sub-modules operating in the actual power grid, which can reproduce the operating characteristics of the module under actual working conditions. At the same time, the protection design of the interface circuit 62 can effectively prevent irreversible damage to the battery cluster 63 caused by test abnormalities. It supports both independent testing of a single energy storage module and testing of high-voltage module groups composed of multiple modules connected in series. It can flexibly cover the testing needs of energy storage products with different voltage levels and power levels, improving the applicability and efficiency of the testing system.

[0040] In some specific embodiments of this application, when the controller under test 4 generates the drive signal, it uses a sinusoidal pulse width modulation method to convert the reference signal into the drive signal under test based on the modulation voltage reference signal that is the same as the actual operating condition; the drive signal under test controls the switching state of the converter circuit in the battery energy storage module 6 under test.

[0041] Specifically, the controller under test receives a modulated voltage reference signal that is completely consistent with the actual operating conditions, and uses sinusoidal pulse width modulation (SPWM) technology to convert the reference signal into a series of pulse-shaped drive signals under test; these drive signals directly control the on and off (i.e., switching state) of the power switching devices in the converter circuit inside the battery energy storage module 6 under test.

[0042] The embodiments described above enable the battery energy storage module 6 under test to realistically reproduce its switching actions and power conversion behavior in an actual power system in a test environment, including steady-state operation and transient disturbance processes, thereby achieving accurate evaluation of the module's dynamic response, harmonic characteristics, and thermal stress distribution. At the same time, the use of sinusoidal pulse width modulation can effectively reduce the harmonic content of the output current, improve the accuracy of operating condition reproduction, and ensure the accuracy and consistency of test data under all operating conditions in the four quadrants of active and reactive power.

[0043] In some specific embodiments of this application, the filter 7 is an L-type filter, an LC-type filter, or an LCL-type filter; the location and number of filters 7 are determined according to the connection method of each unit in the current shaper 5.

[0044] When the active current shaping unit 52 and the reactive current shaping unit 51 are connected in series, a filter 7 is set at any position in the test circuit. When the active current shaping unit 52 and the reactive current shaping unit 51 are connected in parallel, the filter 7 includes a total filter connected in series in the main circuit of the test circuit, and branch filters that are independently connected in series in the active current shaping unit 52 and the reactive current shaping unit 51, respectively.

[0045] Specifically, filter 7 adopts an L-type, LC-type, or LCL-type topology. Its location and number are dynamically determined according to the connection method of the active current shaping unit 52 and the reactive current shaping unit 51 in the current shaper: when the two units are connected in series, filter 7 is arranged at any position in the test circuit (such as the output side of the current shaper 5 or the input side of the module under test); when the two units are connected in parallel, in addition to a total filter connected in series in the main circuit of the test circuit, a branch filter is independently connected in series inside the active current shaping unit 52 and the reactive current shaping unit 51. That is, independent branch filters are connected in series in the output branches of the active current shaping unit 52 and the reactive current shaping unit 51 respectively. The current output by the two units is first filtered independently to suppress their respective switching ripples. Then, a total filter is connected in series in the main circuit of the test circuit to perform secondary filtering on the combined total test current, and finally outputs a low-ripple, high-quality test current to the battery energy storage module under test.

[0046] The embodiments described above in this application achieve an optimal balance between filtering effect and system cost by providing a variety of standardized filter types 7 and adopting differentiated filtering configuration strategies based on the series and parallel connection methods of the current shaper 5. For the simplified architecture of series connection, the use of a single filter 7 significantly reduces hardware cost and system complexity. For the high-performance architecture of parallel connection, the filtering structure of "independent branch filter 7 + main circuit total filter 7" avoids the mutual superposition and interference of the switching ripples of the active and reactive power shaping units, improves the filtering effect, and can control the ripple rate and harmonic distortion rate of the test current to an extremely low level, ensuring the high fidelity of the test current waveform, thereby accurately reproducing the current characteristics under real power grid operating conditions.

[0047] In some specific embodiments of this application, the current shaper controller 3 supports control of the current shaper 5 in multiple operating modes, including: pure active test mode, pure reactive test mode, mixed active and reactive test mode, and independent charging and discharging mode of the active shaping unit.

[0048] In the pure active power test mode, under the pure active power operation condition, the active power required for the test is entirely borne by the active current shaping unit 52, and the output active power of the reactive current shaping unit 51 is near zero. In the pure reactive power test mode, under the pure reactive power operation condition, the AC current required for the test is mainly provided by the reactive current shaping unit 51, and the output current of the active current shaping unit 52 is controlled near zero, and the active power of both branches is near zero. In the active and reactive power mixed test mode, the active current shaping unit 52 and the reactive current shaping unit 51 respectively dominate the active and reactive components of the test current, and independently undertake and decouple the active and reactive power. When the active current shaping unit 52 needs to replenish or consume energy independently, the battery energy storage module 6 under test is controlled to bypass operation, so that the reactive current shaping unit 51 and the active current shaping unit 52 form a counter-carrying structure to replenish or consume energy for the active current shaping unit 52.

[0049] The embodiments described above in this application, by designing four independent and complementary operating modes for the current shaping controller 3—pure active, pure reactive, mixed active and reactive, and independent charging and discharging of the active shaping unit—achieve complete coverage of the full-scenario testing requirements of the battery energy storage module 6 under test. Simultaneously, they maximize the technical advantages of the power decoupling architecture of this application: in the pure active, pure reactive, and mixed testing modes, through clear functional division, the active current shaping unit 52 and the reactive current shaping unit 51 respectively dominate the output of their corresponding power components, avoiding control interference caused by power coupling in traditional integrated power supplies and improving the tracking of test current under various operating conditions. It offers high accuracy and stability, and can flexibly switch modes according to testing requirements, enabling specialized tests of different performance indicators without adjusting the hardware circuit. In particular, the unique active current shaping unit 52 features an independent charging and discharging mode. By bypassing the battery under test energy storage module 6, the existing reactive current shaping unit 51 and active current shaping unit 52 can temporarily form a counter-structure. This eliminates the need for additional dedicated charging and discharging equipment to replenish or consume the DC side energy of the active unit, solving the problem of energy imbalance in the active unit during testing, reducing system hardware costs, shortening test preparation and energy adjustment time, and improving the operating efficiency and automation of the testing system.

[0050] In some specific embodiments of this application, the current shaper controller 3 decouples the total reference current required for testing into mutually orthogonal active current component commands and reactive current component commands through a feedforward and active closed-loop composite control method, specifically including: Based on the test power command of the battery energy storage module 6 under test, the initial decoupling phase angle is calculated as a feedforward quantity; the average active power of the port of the reactive current shaping unit 51 is sampled in real time for a single cycle, and the phase angle compensation quantity is output by the proportional-integral controller; the final decoupling phase angle is obtained by superimposing the feedforward quantity and the phase angle compensation quantity, and the final decoupling phase angle is synthesized with the test current amplitude reference command by trigonometric function, and the test current amplitude reference command is decomposed into mutually orthogonal active current component command and reactive current component command.

[0051] Among them, the magnitude of the decomposed active current component command is proportional to the cosine value of the final decoupling phase angle, and the magnitude of the reactive current component command is proportional to the sine value of the final decoupling phase angle.

[0052] Specifically, when executing the orthogonal decoupling distribution of the test current, the current shaping controller 3 adopts a composite control strategy combining feedforward and active closed-loop: First, it calculates the initial decoupling phase angle as a feedforward quantity based on the test power command of the battery energy storage module 6 under test, so as to achieve a rapid response to the test requirements; at the same time, it samples the single-cycle average active power of the reactive current shaping unit 51 port in real time, inputs its deviation from the zero reference value into the proportional integral controller, and outputs the compensation quantity used to correct the decoupling phase angle; then, it superimposes the feedforward quantity and the phase angle compensation quantity to obtain the final decoupling phase angle, and synthesizes the final decoupling phase angle with the test current amplitude reference command using trigonometric functions. According to the relationship that the active component amplitude is proportional to the cosine value of the final decoupling phase angle and the reactive component amplitude is proportional to the sine value of the final decoupling phase angle, the total reference current is accurately decomposed into mutually orthogonal active current component commands and reactive current component commands, which are then sent to the corresponding shaping units for execution.

[0053] The embodiments described above in this application ensure decoupling speed under dynamic operating conditions by rapidly responding to changes in power commands via feedforward. At the same time, they utilize closed-loop feedback of active power at the reactive power unit port to compensate for phase angle errors in real time, eliminating inaccurate decoupling caused by circuit parameter deviations or transient disturbances. This enables orthogonal decomposition of the active and reactive components of the test current across the entire operating range, allowing the system to accurately reproduce steady-state and transient current commands covering four quadrants of operation. This reduces current distortion rate and simulation errors, and improves the reliability of test results.

[0054] In some specific embodiments of this application, the current shaping controller 3 calculates the initial decoupling phase angle based on the test power command of the battery storage module 6 under test, including: Based on the positive and negative active quadrants and positive and negative reactive quadrants where the test power of the battery energy storage module 6 under test is located, determine the quadrant where the target power factor angle is located; based on the phasor angle between the test current and the AC port voltage of the battery energy storage module 6 under test, the amplitude of the test current, the amplitude of the AC port voltage, and the filter inductor parameters, calculate the phase shift caused by the filter inductor; through the phasor superposition relationship, analytically calculate the initial decoupling phase angle.

[0055] Specifically, when calculating the initial decoupling phase angle, the current shaper controller 3 first determines the quadrant where the target power factor angle is located based on the positive and negative active and reactive quadrants where the test power of the battery energy storage module 6 is located, providing a correct directional reference for the phase angle calculation. Then, based on the phasor angle between the test current and the AC port voltage of the battery energy storage module 6, the amplitude of the test current, the amplitude of the AC port voltage, and the electrical parameters of the filter inductor, it calculates the inherent phase offset generated by the filter inductor during current transmission. Finally, through the mathematical relationship of phasor superposition, the initial decoupling phase angle is directly solved analytically, serving as the core input quantity for feedforward control.

[0056] The embodiments described above in this application solve the problem of initial phase angle deviation caused by neglecting the phase influence of filter components in traditional open-loop decoupling control by introducing an initial decoupling phase angle calculation method based on power quadrant judgment and filter inductor phase offset compensation, thereby improving the initial accuracy of feedforward control. Simultaneously, the analytical calculation method replaces the traditional iterative solution, accelerating the calculation speed of the initial phase angle and enhancing the system's dynamic response to changes in test commands. By explicitly judging the power quadrant, quadrant confusion errors in phase angle calculation are avoided, ensuring the correctness and reliability of decoupling control under all operating conditions in the active-reactive four-quadrant configuration. The adjustment burden of the continuous active closed-loop compensation link is reduced, and in conjunction with the feedforward + active closed-loop composite control strategy, the current tracking accuracy and steady-state operation stability of the entire system are further improved.

[0057] In some specific embodiments of this application, the current shaping unit controller 3 controls the active current shaping unit 52 and the reactive current shaping unit 51 to output corresponding currents to follow commands through active DC voltage stabilization control and current closed-loop control, specifically including: The DC-side voltage deviation of the reactive current shaping unit 51 is used to generate a compensation current command via a proportional-integral controller or a proportional controller. The compensation current command is positively superimposed onto the reference command of the reactive current component, and an equal and reversed compensation current command is superimposed onto the reference command of the active current component, so that the active current shaping unit 52 actively absorbs unbalanced energy. A proportional-integral-resonant controller is used to enable the actual currents of the active current shaping unit 52 and the reactive current shaping unit 51 to track the fundamental frequency sinusoidal current command, generating the modulation voltages of the active current shaping unit 52 and the reactive current shaping unit 51, and using sinusoidal pulse width modulation to generate the drive signals of the active current shaping unit 52 and the reactive current shaping unit 51.

[0058] Specifically, when controlling the active current shaping unit 52 and the reactive current shaping unit 51 to accurately track their respective current commands, the current shaping controller 3 adopts a collaborative control strategy that deeply integrates active DC voltage stabilization control and current closed-loop control: First, the DC side voltage of the reactive current shaping unit 51 is collected in real time, and its deviation value from the preset reference voltage is input to the proportional-integral controller or proportional controller to generate a compensation current command for balancing DC side energy fluctuations; then, this compensation current command is positively superimposed onto the reference command of the reactive current component, while a compensation current command of equal value but opposite direction is superimposed onto the active current component. In the reference command for the current component, the bidirectional power flow capability of the active current shaping unit 52 is used to actively absorb the unbalanced energy generated in the system, thereby achieving closed-loop stable control of the DC side voltage of the reactive current shaping unit 51. Finally, a proportional-integral-resonant controller is used to perform closed-loop adjustment of the actual output current of the two shaping units and the corresponding reference command, respectively, to achieve high-precision, zero-steady-state-error tracking of the fundamental frequency sinusoidal current command, generate the modulation voltage signal of the two shaping units, and convert it into a pulse signal to drive the switching transistors of each converter through sinusoidal pulse width modulation, so as to accurately control the converter output to meet the high-quality current requirements of the test.

[0059] The embodiments described above in this application, through the collaborative design of active DC voltage stabilization control and current closed-loop control, adapt to the characteristics of the power decoupled hardware architecture of this application. No additional dedicated energy storage buffer or voltage regulator circuit is required; the core problem of unidirectional DC power supplies being unable to handle unbalanced active power is completely solved solely through innovative control algorithms. By symmetrically superimposing compensation current commands bidirectionally onto the active and reactive current reference commands, the bidirectional power flow capability of the active current shaping unit 52 is utilized to handle DC-side energy fluctuations in the reactive unit, ensuring that the reactive current shaping unit 51 always operates in a zero active power state. This avoids the risk of overvoltage damage to the unidirectional power supply caused by energy feedback and achieves rapid and stable regulation of the DC-side voltage of the reactive unit. Simultaneously, a proportional-integral-resonant controller is used instead of a traditional proportional-integral controller, enabling zero steady-state error tracking of the fundamental frequency sinusoidal current command, improving the tracking accuracy and steady-state performance of the AC current, and suppressing current harmonic distortion.

[0060] Among them, the collaborative control strategy of deep integration of active DC voltage stabilization control and current closed-loop control in this application, together with the feedforward + active power closed-loop composite decoupling control, forms a complete control closed loop from current orthogonal decoupling distribution to precise tracking and DC voltage stabilization. This improves the operational stability and test current quality of the entire test system under the full operating conditions of active and reactive power four quadrants, and provides a reliable control guarantee for the high-precision performance testing of the battery energy storage module under test.

[0061] Reference Figure 4As shown, based on the same inventive concept, another specific embodiment of this application provides a power decoupling type operating condition simulation test method for a battery energy storage module, which can be applied to any of the above-mentioned embodiments of the power decoupling type operating condition simulation test system for battery energy storage modules, including: S1. The total current required for the test is decoupled into active current component and reactive current component by the current shaping controller, and the active current shaping unit and reactive current shaping unit are controlled to output the corresponding current respectively to achieve power decoupling and DC voltage stabilization. S2. Generate and control the drive signal of the battery energy storage module under test through the controller under test, so that it matches the actual operating conditions.

[0062] In the embodiments described above, the current shaping controller first decouples the total reference current required for the test into mutually orthogonal active current components and reactive current components through a feedforward and active closed-loop composite control method. Then, it controls the active current shaping unit with bidirectional power supply and the reactive current shaping unit with unidirectional power supply to output corresponding currents respectively. At the same time, through active DC voltage stabilization control and current closed-loop control, it realizes the decoupled distribution of active and reactive power and DC voltage stabilization, and allows the active current shaping unit to actively absorb transient unbalanced energy. Meanwhile, the controller under test receives test commands simulating a real energy storage system, generates drive signals that match the actual operating conditions to control the battery energy storage module under test, and completes the performance test of the module under test by cooperating with the closed-loop test circuit composed of the current shaping unit, the battery energy storage module under test, and the filter connected in series. It allows reactive power to be handled independently by a low-cost unidirectional power supply unit, eliminating the need for expensive high-power bidirectional power supplies. While covering the full operating boundary of the four quadrants of active and reactive power, it reduces the hardware cost of the equipment. Furthermore, through composite closed-loop active shaping control of the test current, it changes the traditional open-loop mode that relies on voltage difference to indirectly generate current, reduces the distortion rate and simulation error of the test current under steady-state conditions, and improves the dynamic response accuracy under large disturbance step conditions such as cross-quadrant switching. It can accurately evaluate the true electrothermal characteristics and transient tolerance of the battery energy storage module under test.

[0063] The preferred features in the above embodiments can be used individually in any embodiment, or in any combination thereof, provided they do not conflict with each other. Furthermore, parts not described in detail in the embodiments can be implemented using existing technologies.

[0064] The foregoing has described some specific embodiments of this application. It should be understood that this application is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the substantive content of this application. The above-described preferred features can be used in any combination without conflict.

Claims

1. A power decoupling type operating condition simulation test system for a battery energy storage module, characterized in that... ,include: The test circuit includes a current shaper, a battery energy storage module under test, and a filter. The current shaper consists of an active current shaping unit and a reactive current shaping unit connected in series or parallel, used to actively control and shape a test current covering the active and reactive four quadrants of the tested object. The AC port of the battery energy storage module under test is connected in series with the current shaper and the filter to form a closed-loop test circuit, used to receive the test current and drive signal consistent with actual operating conditions. The filter is connected in series in the closed-loop test circuit to reduce the ripple rate of the test current. The current shaping controller decouples the total reference current required for testing into mutually orthogonal active current component commands and reactive current component commands, and controls the active current shaping unit and the reactive current shaping unit to output corresponding currents to follow the commands, while simultaneously stabilizing the DC voltage. The controller under test receives test commands simulating a real energy storage system, generates and controls the drive signals of the battery energy storage module under test to make it match the actual operating conditions.

2. The power decoupling type operating condition simulation test system for battery energy storage modules according to claim 1, characterized in that, The converters in both the active current shaping unit and the reactive current shaping unit are H-bridge converters or half-bridge converters. The reactive current shaping unit is configured as a unidirectional power supply to handle the test reactive power. The unidirectional power supply is a unidirectional DC voltage source or a DC regulated power supply with a unidirectional diode connected in series. The unidirectional diode is used to block the energy reverse feedback path. The active current shaping unit is configured as a bidirectional power supply with bidirectional power flow capability to handle the tested active power. The bidirectional power source is a battery pack or a bidirectional DC voltage source, which has bidirectional power flow capability and is used to actively absorb transient unbalanced energy during testing.

3. The power decoupling type operating condition simulation test system for battery energy storage modules according to claim 1, characterized in that, The battery energy storage module under test includes an H-bridge converter under test, an interface circuit, and a battery cluster. The DC side of the H-bridge converter under test is connected in parallel with the battery cluster via the interface circuit, and the AC side of the H-bridge converter under test is connected to the test circuit to receive the test current.

4. The power decoupling type operating condition simulation test system for battery energy storage modules according to claim 1, characterized in that, When generating the drive signal, the controller under test converts the reference signal into a drive signal under test using a sinusoidal pulse width modulation method based on the modulation voltage reference signal that is the same as the actual operating condition; the drive signal under test controls the switching state of the converter circuit in the battery energy storage module under test.

5. The power decoupling type operating condition simulation test system for battery energy storage modules according to claim 1, characterized in that, The filter is an L-type filter, an LC-type filter, or an LCL-type filter; the location and number of the filters are determined according to the connection method of each unit in the current shaper. When the active current shaping unit and the reactive current shaping unit are connected in series, a filter is set at any position in the test circuit. When the active current shaping unit and the reactive current shaping unit are connected in parallel, the filter includes a total filter connected in series in the main circuit of the test circuit, and branch filters that are independently connected in series in the active current shaping unit and the reactive current shaping unit, respectively.

6. The power decoupling type operating condition simulation test system for battery energy storage modules according to claim 1, characterized in that, The current shaper controller controls the current shaper in multiple operating modes, including: pure active test mode, pure reactive test mode, mixed active and reactive test mode, and independent charging and discharging mode of active shaping unit; In the pure active power test mode, under pure active power operation conditions, the active power required for the test is entirely borne by the active current shaping unit, and the output active power of the reactive current shaping unit is near zero. In the pure reactive power test mode, under the pure reactive power operation condition, the AC current required for the test is mainly provided by the reactive current shaping unit, the output current of the active current shaping unit is controlled near zero, and the active power of both the active current shaping unit and the reactive current shaping unit is near zero. In the active and reactive power mixed test mode, under the active and reactive power mixed operation condition, the active current shaping unit and the reactive current shaping unit respectively dominate the active and reactive components of the test current, and independently undertake and decouple the active and reactive power. The independent charging and discharging mode of the active current shaping unit controls the bypass operation of the battery storage module under test when the active current shaping unit needs to replenish or consume energy separately, so that the reactive current shaping unit and the active current shaping unit form a counter-carrying structure to replenish or consume energy for the active current shaping unit.

7. The power decoupling type operating condition simulation test system for battery energy storage modules according to claim 1, characterized in that, The current shaper controller, through a feedforward and active closed-loop composite control method, decouples the total reference current required for testing into mutually orthogonal active current component commands and reactive current component commands, specifically including: Based on the test power command of the battery energy storage module under test, the initial decoupling phase angle is calculated as the feedforward quantity; The average active power of the reactive current shaping unit is sampled in real time for a single cycle, and the phase angle compensation is output through a proportional-integral controller. The final decoupling phase angle is obtained by superimposing the feedforward amount and the phase angle compensation amount, and the final decoupling phase angle is synthesized with the test current amplitude reference command by trigonometric function. The test current amplitude reference command is decomposed into the active current component command and the reactive current component command that are orthogonal to each other. The magnitude of the decomposed active current component command is proportional to the cosine of the final decoupling phase angle, and the magnitude of the reactive current component command is proportional to the sine of the final decoupling phase angle.

8. The power decoupling type operating condition simulation test system for battery energy storage modules according to claim 7, characterized in that, The current shaping controller calculates the initial decoupling phase angle based on the test power command of the battery storage module under test, including: Based on the positive and negative active quadrants and positive and negative reactive quadrants where the test power of the battery energy storage module under test is located, determine the quadrant where the target power factor angle is located; Based on the phasor angle between the test current and the AC port voltage of the battery energy storage module under test, the amplitude of the test current, the amplitude of the AC port voltage, and the filter inductor parameters, the phase shift caused by the filter inductor is calculated. The initial decoupling phase angle is obtained analytically by using the phasor superposition relationship.

9. The power decoupling type operating condition simulation test system for battery energy storage modules according to claim 7, characterized in that, The current shaping controller, through active DC voltage stabilization control and current closed-loop control, controls the active current shaping unit and the reactive current shaping unit to output corresponding currents to follow the command, specifically including: The DC-side voltage deviation of the reactive current shaping unit is used to generate a compensation current command via a proportional-integral controller or a proportional controller. The compensation current command is positively superimposed onto the reference command of the reactive current component, and at the same time, the compensation current command of equal value and opposite direction is superimposed onto the reference command of the active current component, so that the active current shaping unit actively absorbs unbalanced energy. A proportional-integral-resonant controller is used to enable the actual current of the active current shaping unit and the reactive current shaping unit to track the fundamental frequency sinusoidal current command, generate the modulation voltage of the active current shaping unit and the reactive current shaping unit, and generate the drive signal of the active current shaping unit and the reactive current shaping unit using a sinusoidal pulse width modulation method.

10. A power decoupling type operating condition simulation test method for a battery energy storage module, applied to the test system described in any one of claims 1-9, characterized in that, include: The total current required for the test is decoupled into active current component and reactive current component by the current shaping controller, and the active current shaping unit and reactive current shaping unit are controlled to output the corresponding current respectively to achieve power decoupling and DC voltage stabilization. The drive signal of the battery energy storage module under test is generated and controlled by the controller under test to make it match the actual operating conditions.

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