A single-phase energy storage converter full-load test system and method

Abstract

The present invention provides a single-phase energy storage converter full-load test system and method, which includes two novel full-bridge energy storage converter modules and a test platform power supply system. The novel full-bridge energy storage converter module includes a full-bridge converter and one or more parallel-connected DC converters connected to its DC side. The output end of the DC converter is subjected to DC output through a filter. The AC sides of the two novel full-bridge energy storage converter modules are connected through reactor L01 and reactor L02, and the DC sides of the two novel full-bridge energy storage converter modules are connected in parallel to the DC power supply end of the test platform power supply system. The adopted test and control method enables the two novel full-bridge energy storage converter modules to output voltages and currents with arbitrary frequencies, amplitudes, and phases, and form a loop without significant energy exchange with the external system. It can be used for various load tests of the novel energy storage converter module, has no requirement for the system capacity, and the system only needs to provide the module loss to complete various tests required for module factory shipment.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage control, and particularly relates to a single-phase energy storage converter full-load test system and method. Background Art

[0002] With the rapid development of human society, the increasing demand for energy by humans, and the growing urgency of the requirements for carbon neutrality and carbon peak by countries around the world, various new energy storage devices have seen a huge market demand in recent years.

[0003] Currently, in energy storage devices, most of the converter structures use traditional two-level and three-level structures. The traditional structures are simple to control, have high efficiency, and low cost, but they cannot be directly connected to high-voltage systems and have small capacities. If applied to high-voltage scenarios, step-up transformers and multiple parallel energy storage devices are required, resulting in problems such as high failure rates and easy system resonance.

[0004] The new type of full energy storage converter is based on a cascaded topology structure and adds a DC converter, with advantages such as large single-machine capacity and direct connection to high voltage.

[0005] Therefore, the inventor of the present invention proposed a single-phase energy storage converter full-load test method, which can be used for various load tests of new energy storage converter modules, has no requirements for system capacity, and the system only needs to provide module losses to complete various tests required for module factory shipment. Summary of the Invention

[0006] In order to solve the technical problems raised in the background art, the present invention provides a single-phase energy storage converter full-load test system and method, which can provide a load test environment for new full-bridge energy storage converter modules, can be used for various load tests of new energy storage converter modules, has no requirements for system capacity, and the system only needs to provide module losses to complete various tests required for module factory shipment.

[0007] To achieve the above object, the present invention is implemented by the following technical solutions:

[0008] A single-phase energy storage converter full-load test system includes two new full-bridge energy storage converter modules and a test platform power supply system. The new full-bridge energy storage converter module includes a full-bridge converter and one or more parallel DC converters connected to its DC side. The output end of the DC converter is subjected to DC output through a filter.

[0009] The AC sides of the two new full-bridge energy storage converter modules are connected through reactor L01 and reactor L02, and the DC sides of the two new full-bridge energy storage converter modules are connected in parallel to the DC power supply end of the test platform power supply system.

[0010] Further, the DC converter is of a buck circuit structure.

[0011] Further, the filter described above is an LC filter.

[0012] Further, the AC sides of the two novel full-bridge energy storage converter modules are connected through reactor L01 and reactor L02. Specifically, the half-bridge output node in one novel full-bridge energy storage converter module is connected to the half-bridge output node in the other novel full-bridge energy storage converter module through reactor L01 and reactor L02.

[0013] A full-load test method for a single-phase energy storage converter full-load test system includes the following:

[0014] The test platform power supply system provides an adjustable DC voltage to charge the capacitors in the two novel full-bridge energy storage converter modules to any value lower than the tolerance value of the selected device. After charging is completed, unlock the DC converter, control the DC-side capacitor voltages C1 and C2 of the full-bridge converters in the two novel full-bridge energy storage converter modules to the set value UdcRef. After stabilization, unlock the full-bridge converter and output the command current Iref. The frequency, amplitude, and phase of this command current can be adjusted arbitrarily.

[0015] It includes a full-bridge converter control method and a DC converter control method.

[0016] Further, the full-bridge converter control method is as follows:

[0017] Full-bridge converter control method: Perform voltage open-loop control on the full-bridge converter of one novel full-bridge energy storage converter module to output a voltage with a set frequency and amplitude, and perform current closed-loop control on the full-bridge converter of the other novel full-bridge energy storage module to output a current with a set amplitude and phase.

[0018] Further, the DC converter control method is as follows:

[0019] DC converter control method: Perform voltage and current double closed-loop control on the DC converters of the two novel full-bridge energy storage converter modules to stably control the full-bridge capacitor voltage and the DC converter current.

[0020] Further, in the voltage and current double closed-loop control, the voltage loop control target is the capacitor voltages UdcFbk1 and UdcFbk2 of the DC-side capacitors C1 and C2 of the full-bridge converter, and the current loop control target is the DC converter output currents IdcFbk11... IdcFbk1n, IdcFbk21... IdcFbk2n, where n is the number of parallel DC converters.

[0021] Furthermore, the full-bridge converter control method and the DC converter control method enable the two novel full-bridge energy storage converter modules to output voltages and currents with arbitrary frequencies, amplitudes, and phases, and form a loop with no significant energy exchange with the external system. Only the power supply system of the test platform needs to provide energy loss to achieve various load tests of the equipment.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] 1) Compared with the traditional test method for energy storage converter modules, the advantage of the present invention is that it does not need to connect to a battery pack, does not need to provide a DC simulation device, does not need to interact with the power grid with high power, and can test multiple converter modules simultaneously.

[0024] 2) The full-bridge converter control method and the DC converter control method adopted by the present invention enable the two novel full-bridge energy storage converter modules to output voltages and currents with arbitrary frequencies, amplitudes, and phases, and form a loop with no significant energy exchange with the external system. Only the power supply system of the test platform needs to provide energy loss to achieve various load tests of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is the system structure diagram of the test platform for the novel full-bridge energy storage converter module of the present invention.

[0026] Figure 2 is the structural topology diagram of the novel full-bridge energy storage converter module of the present invention.

[0027] Figure 3 is the full-bridge control logic block diagram in the test platform for the novel full-bridge energy storage converter module of the present invention.

[0028] Figure 4 is the DC converter control logic block diagram in the test platform for the novel full-bridge energy storage converter module of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] The following provides a detailed description of the specific embodiments provided by the present invention in conjunction with the accompanying drawings.

[0030] As Figure 1 shown, the system structure diagram of the test platform for the novel full-bridge energy storage converter module of the present invention includes two novel full-bridge energy storage converter modules and a test platform power supply system. The novel full-bridge energy storage converter module includes a full-bridge converter and one or more parallel DC converters connected to its DC side. The output end of the DC converter is DC output through a filter. The test platform for the novel full-bridge energy storage converter module is provided with a stable DC voltage by the test platform power supply system. The output ends of the DC converters in the energy storage converter module are connected in parallel to the DC side DC_Out of the test platform power supply system. The AC sides of the novel full-bridge energy storage converters are connected through two reactors L01 and L02.

[0031] As Figure 2 shown, the topological structure diagram of the novel full-bridge energy storage converter module of the present invention is based on the traditional full-bridge converter. One or more DC converters are connected in parallel at the ends of the DC-side capacitors C1 and C2, and an LC filter is added to the output end of the DC converter.

[0032] The test method of the present invention is as follows: The power supply system of the test platform provides an adjustable DC voltage to charge the capacitors of the energy storage converter (including the DC-side capacitors C1 and C2 of the full-bridge converter, and the filter capacitors C11, C1n, C21, and C2n of the DC converter) to any value lower than the tolerance value of the selected device. After the charging is completed, unlock the DC converter to control the voltages of C1 and C2 to the set value UdcRef. After the control is stable, the full-bridge converter can be unlocked to output the command current Iref, and the frequency, amplitude, and phase of this command current can be adjusted arbitrarily.

[0033] As Figure 3 shown, it is the full-bridge control logic block diagram of the present invention. Among them, the novel full-bridge energy storage converter module 1 operates in the voltage control mode, and the output voltage Umod1, frequency f, amplitude A, and phase α can all be adjusted arbitrarily. The novel full-bridge energy storage converter module 2 operates in the current control mode, and the output current Iref, frequency f, amplitude B, and phase β can all be adjusted arbitrarily. The current loop control adopts the PI control algorithm.

[0034] As Figure 4 shown, it is the control logic block diagram of the DC converter of the present invention, which adopts the voltage and current double-closed-loop control method. The control target of the voltage loop is the capacitor voltages UdcFbk1 and UdcFbk2 of C1 and C2, and the control target of the current loop is the output currents IdcFbk11, IdcFbk1n, IdcFbk21, and IdcFbk2n of the DC converter. Both of its double-closed-loop controls adopt the PI control algorithm.

[0035] The above embodiments are implemented on the premise of the technical solution of the present invention, and the detailed implementation manners and specific operation processes are given. However, the protection scope of the present invention is not limited to the above embodiments. The methods used in the above embodiments are all conventional methods unless otherwise specified.

Claims

1. A testing method for a full-load testing system of a single-phase energy storage converter, characterized in that, The test system includes two new full-bridge energy storage converter modules and a test platform power supply system. The new full-bridge energy storage converter module includes a full-bridge converter and one or more parallel DC converters connected to its DC side. The output end of the DC converter is subjected to DC output through a filter. The AC sides of the two new full-bridge energy storage converter modules are connected through reactors L01 and L02. The DC sides of the two new full-bridge energy storage converter modules are connected in parallel to the DC power supply end of the test platform power supply system. The test method of the test system includes: The test platform power supply system provides an adjustable DC voltage to charge the capacitors in the two new full-bridge energy storage converter modules to any value lower than the tolerance value of the selected device. After the charging is completed, unlock the DC converter, control the voltages of the DC side capacitors C1 and C2 of the full-bridge converters in the two new full-bridge energy storage converter modules to the set value UdcRef. After the control is stable, unlock the full-bridge converter and output the command current Iref, and the frequency, amplitude, and phase of this command current can be adjusted arbitrarily.

2. The testing method of a single-phase energy storage converter full-load testing system according to claim 1, characterized in that The DC converter mentioned above has a buck circuit structure.

3. The testing method of a single-phase energy storage converter full-load testing system according to claim 1, characterized in that The filter mentioned above is an LC filter.

4. The test method of a single-phase energy storage converter full-load test system according to claim 1, characterized in that The specific connection of the AC sides of the two new full-bridge energy storage converter modules through reactors L01 and L02 is that the half-bridge output node in one new full-bridge energy storage converter module is connected to the half-bridge output node in the other new full-bridge energy storage converter module through reactors L01 and L02.

5. The testing method of a single-phase energy storage converter full-load testing system according to claim 1, characterized in that During the test, the control method adopted by the full-bridge converter is as follows: Full-bridge converter control method: Perform voltage open-loop control on the full-bridge converter of one of the new full-bridge energy storage converter modules to output a voltage with a set frequency and amplitude, and perform current closed-loop control on the full-bridge converter of the other new full-bridge energy storage module to output a current with a set amplitude and phase.

6. The test method of a single-phase energy storage converter full-load test system according to claim 1, characterized in that, During the test, the control method adopted by the DC converter is as follows: DC converter control method: Perform voltage and current double closed-loop control on the DC converters of the two new full-bridge energy storage converter modules to stably control the full-bridge capacitor voltage and the DC converter current.

7. The test method of a single-phase energy storage converter full-load test system according to claim 6, characterized in that, In the voltage and current double closed-loop control, the control target of the voltage loop is the capacitor voltages UdcFbk1 and UdcFbk2 of the DC side capacitors C1 and C2 of the full-bridge converter, and the control target of the current loop is the DC converter output currents IdcFbk11……IdcFbk1n, IdcFbk21……IdcFbk2n, where n is the number of parallel DC converters.

8. The testing method of a single-phase energy storage converter full-load testing system according to claim 5 or 6, characterized in that The full-bridge converter control method and the DC converter control method mentioned above enable the two new full-bridge energy storage converter modules to output voltages and currents with arbitrary frequencies, amplitudes, and phases, and form a loop without significant energy exchange with the external system. Only the test platform power supply system needs to provide energy loss to realize various load tests of the equipment.

Images