Automatic testing device for power module of H-bridge cascaded high-voltage energy storage system

Abstract

The invention relates to an automatic testing device for a power module of an H-bridge cascaded high-voltage energy storage system, and belongs to the technical field of energy storage system testing. The automatic testing device for the power module of the H-bridge cascaded high-voltage energy storage system comprises a power supply loop, an oscilloscope, an interaction module, a main control board, a communication interface, an alternating current waveform input interface and a power supply output interface. The oscilloscope is connected with the AC waveform input interface, the test power supply output interface is connected with a battery port of a tested power module, and the AC waveform input interface is used for connecting an AC port of the tested power module; the interaction module is connected with the main control board and the power supply to supply power to the testing device; the main control board sends a control instruction and receives state information of the tested power module; the interaction module is used for inputting a test instruction and displaying state information. During use, a test instruction is issued through the display screen, and a test result is displayed on the display screen, so that the complexity of power module test is reduced, the operation stability of the power module and the field fault maintenance efficiency are improved, and the cost is reduced.

Description

Technical Field

[0001] The present invention relates to an automatic test device for a power module of an H-bridge cascaded high-voltage energy storage system, belonging to the technical field of energy storage system testing. Background Art

[0002] The H-bridge cascaded high-voltage energy storage system is a new type of energy storage system. As primary equipment, it can directly operate in a 35 kV power grid system without passing through a transformer. The energy storage converter system based on H-bridge cascade has a large capacity and does not include primary equipment such as busbar cabinets and industrial frequency transformers, which not only saves costs but also reduces system losses and costs. Each battery cluster allows discrete battery units to be connected to each H-bridge, with good redundancy. The power module of the H-bridge cascaded high-voltage energy storage system contains many components, which increases the workload and technical difficulty for performance testing and fault location of the power module. Therefore, it is particularly important to design an automatic test device for the power module. Summary of the Invention

[0003] The purpose of the present invention is to provide an automatic test device for a power module of an H-bridge cascaded high-voltage energy storage system to solve the problems of difficult functional testing and fault location of the power module.

[0004] To achieve the above purpose, the solution of the present invention includes: during formal testing, after closing the switch to power on the automatic test device for the power module and the power module to be tested normally, control instructions can be sent through the display screen to perform tests such as input / output testing and open-loop wave generation testing, and the test results are displayed on the display screen.

[0005] An automatic test device for a power module of an H-bridge cascaded high-voltage energy storage system of the present invention includes a power supply circuit, an oscilloscope, an interaction module, a main control board, a communication interface, an AC waveform input interface, and a power output interface. Among them, the power supply circuit is connected to the test power output interface, the oscilloscope is connected to the AC waveform input interface, the test power output interface is connected to the battery port of the power module to be tested to provide test power, and the AC waveform input interface is used to connect to the AC port of the power module to be tested; the interaction module is connected to the main control board and the power supply to supply power to the test device; the main control board is connected to the module control board of the power module to be tested through the communication interface to send control instructions and receive the status information of the power module to be tested; the interaction module is used to input test instructions and display status information.

[0006] Further, it also includes an AC interface for connecting to the commercial power, and the other end of the power supply circuit is connected to the AC interface; a step-up transformer is provided in the power supply circuit, and a rectifier circuit is provided between the secondary winding of the step-up transformer and the test power output interface.

[0007] Further, the rectifier circuit includes a diode connected in series on the line connected to the first stage of the secondary winding of the transformer, and a capacitor and a resistor connected in parallel to the output interface of the test power supply. The conduction direction of the diode points to the output interface of the test power supply.

[0008] Further, an inductor is also connected in series on the first stage of the secondary side of the transformer, and a fuse for protecting the power module under test is connected in series on the other stage.

[0009] Further, a sampling module is also included. The sampling module is used to collect the voltage value in the power supply circuit and send it to the main control board; An interface board for optoelectronic conversion is also included. The communication interface is a fiber optic interface. The main control board is connected to the fiber optic interface and the sampling module through the interface board.

[0010] Further, the power supply module includes a first switching power supply and a second switching power supply. The first switching power supply is used to supply power to the main control board and the interaction module respectively, and the second switching power supply is used to supply power to the sampling module.

[0011] Further, the power supply module draws power from the power supply circuit between the AC interface and the primary winding of the boost transformer.

[0012] Further, a first circuit breaker is also provided on the power supply circuit between the AC interface and the primary winding of the boost transformer; a second circuit breaker is also provided between the secondary winding of the transformer and the battery port.

[0013] The beneficial effects of the present invention are as follows: After closing the switch to power on the power module automatic test device and the power module under test normally, control commands can be issued through the display screen to perform tests such as input / output tests and open-loop wave generation tests. The test results are displayed on the display screen. Whether it is the routine test of the power module in the factory or the stability test and fault location of the power module before the equipment is connected to the grid at the engineering site, the power module automatic test device of the H-bridge cascaded high-voltage energy storage system of the present invention can test various test contents such as the software and hardware of the power module without disassembling the power module, reducing the complexity of the power module test, improving the operation stability of the power module and the on-site fault repair efficiency, and reducing the input cost. Description of the Drawings

[0014] Figure 1 : Electrical diagram of the main circuit of the H-bridge cascaded high-voltage energy storage system; Figure 2 : Electrical diagram of the H-bridge cascaded high-voltage energy storage module; Figure 3 : Module diagram of the power module automatic test device of the H-bridge cascaded high-voltage energy storage system; Figure 4 : Composition diagram of the power module automatic test device of the H-bridge cascaded high-voltage energy storage system; Figure 5 : Test flow chart of the power module automatic test device. Specific implementation manners

[0015] To make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be described in detail clearly and completely below with reference to the accompanying drawings and embodiments.

[0016] Device embodiment: As Figure 1 shown, the H-bridge cascaded high-voltage energy storage system is a new type of energy storage system. As a primary device, it can directly operate in the 35 kV power grid system without passing through a transformer. Based on the H-bridge cascaded energy storage converter, the system has a large capacity and does not include primary devices such as busbar cabinets and industrial frequency transformers, which not only saves costs but also reduces system losses and costs. Each battery cluster allows discrete battery units to be connected to each H-bridge, with good redundancy.

[0017] As Figure 3 shown, an automatic test device for the power module of the H-bridge cascaded high-voltage energy storage system of the present invention includes: a power supply circuit 11 connected to the test power supply output interface and an oscilloscope 7 connected to the AC waveform input interface. The test power supply output interface is used to connect to the battery port of the power module to be tested to provide a test power supply, and the AC waveform input interface is used to connect to the AC port of the power module to be tested; it also includes a main control board 3, an interaction module 13 connected to the main control board, and a power module 12 for supplying power to the test device; the main control board 13 is used to connect to the module control board of the power module to be tested through a fiber optic interface 15 to send control instructions and receive the status information of the power module to be tested; the interaction module 13 is used to input test instructions and display the status information.

[0018] Specifically, with reference to Figure 4 the automatic test device for the power module of the H-bridge cascaded high-voltage energy storage system of the present invention will be further described: The power supply circuit 11 includes a transformer 8, a first circuit breaker KF1, a second circuit breaker KF2, and a rectifying circuit; the power supply circuit 11 is also connected to a 220V power supply 9 to obtain power. The first switch KF1 is connected in parallel with the main coil of the transformer 8 to control the on / off of the circuit between the power supply circuit and the power supply 9; the second circuit breaker KF2 is connected in parallel with both poles of the secondary winding of the transformer 8 to control the on / off of the circuit for the power supply path to supply power to the battery port; the rectifying circuit includes diodes, capacitors, and resistors. The diodes are connected in series with one pole of the secondary winding of the transformer, and the capacitors and resistors are connected in series with both poles of the secondary winding of the transformer; the function of the rectifying circuit is to convert alternating current into direct current to supply power to the DC side of the power module.

[0019] Further, the power supply circuit 11 further includes an inductor R and a fuse FU; the inductor R is connected in series with one pole of the secondary winding of the transformer 8 to maintain the stability of the current in the power supply circuit 11; the fuse FU is connected in series with the input end of the transformer 8 to protect the power module under test.

[0020] Further, the sampling module 16 includes an AD sampling board 4, and the AD sampling board 4 collects the voltage value in the power supply circuit 11 and sends it to the main control board 3 through the optical fiber interface 15.

[0021] Further, the power supply module 11 includes a first switching power supply and a second switching power supply. The first switching power supply supplies power to the main control board 3 and the interaction module 13 respectively, and converts the 220V voltage of the commercial power into 24V DC power to supply power to the main control board 3 and the interaction module 13; the second switching power supply converts the 220V commercial power into 15V to supply power to the sampling module 16.

[0022] Further, the first switching power supply 1 and the second switching power supply 2 draw power from the line between the two poles of the primary winding of the power supply and the transformer 8.

[0023] Further, the oscilloscope 7 displays the waveform of the alternating current in the power module under test.

[0024] As Figure 2 shown, the power module of the H-bridge cascaded high-voltage energy storage system includes a battery, a power module, a high-voltage box, a power supply module, and a management module.

[0025] The power module includes an H-bridge composed of 4 insulated gate bipolar transistors IGBTs, a circuit breaker K1, a capacitor C, a reactor L1, a soft start resistor R1, a soft start contactor KM1, a bypass contactor KM2, a resistor R2, a resistor R3, a resistor R4, a current transformer H1, etc. The AC ports A and B of the H-bridge are connected to the high-voltage power grid. The resistors R2, R3, and R4 are connected in parallel at the DC end of the H-bridge to maintain the voltage stability of the circuit in the power module. A soft start contactor KM1, a soft start resistor R1, and a bypass contactor KM2 are arranged between the H-bridge and the positive pole of the battery and form a soft start circuit to prevent the current in the power module circuit from mutating when the soft start contactor KM1 and the soft start contactor KM2 are closed.

[0026] The high-voltage box includes a DC circuit breaker KF1, a DC circuit breaker KF2, a current transformer H1, a fuse FU1, a fuse FU2, etc.

[0027] The power supply module includes a high-voltage power supply 21, a high-voltage power supply 22, and a power supply chip S1. The power supply chip S1 draws 220V power from the high-voltage power supply 21 and the high-voltage power supply 22 and converts it into 24V to supply power to the management module. The high-voltage power supply 21 also provides the commercial power voltage for the devices with the commercial power voltage in the module control board in the control module.

[0028] The control module includes a power module control board and a BCU (Battery Control Unit). The module control board communicates with the battery control unit BCU via the RS485 communication protocol or the CAN bus. The battery control unit BCU communicates with the upper-level optical fiber management machine. The module control board is connected to the interface board in the power module automatic test device via an optical fiber to interact with each other for data. When the power module automatic test device is working, the tester selects test items through the display screen, and the test instructions are sent to the main control module. The main control module sends the instructions to the module control board via the interface board. The module control board sends commands to the battery control unit BCU according to different instructions to control the relevant devices in the power module to perform corresponding operations, and sends the obtained data to the interface board and then to the main control board. The main control board compares the test instructions with the data obtained from the module control board. When it is greater than the set value, a fault is displayed on the display screen.

[0029] Specifically, as Figure 5 shown, during formal testing, after the power module automatic test device is correspondingly connected to the power module, the first circuit breaker KF1 and the second circuit breaker KF2 are closed to power on the power module and the automatic test device. The tester selects test commands on the display screen of the automatic test device. The test instructions include module switch input and output test instructions, module polarity test instructions, module open-loop wave generation test instructions, module voltage sampling test instructions, etc.: The function of the module switch input and output test instruction is to perform opening and closing tests on the switches in the power module, including the soft start contactor KM1, bypass contactor KM2, etc. The on-off state of the corresponding switch is verified by the sound of the corresponding switch action or by reading the current state of the corresponding switch from the module control board and displaying it on the display screen, so that the tester can verify the opening and closing functions of each switch.

[0030] The function of the module polarity test instruction is to test the polarity of the positive and negative busbars at the battery port of the power module. By conducting the corresponding insulated gate bipolar transistor IGBT in the H-bridge through the module control board, the voltage of the corresponding two poles is detected from the AC port to verify whether the power module polarity is correctly connected; for example, when controlling the gates S1 and S4 in the H-bridge to conduct, if the polarity is correctly connected, the waveform displayed by the oscilloscope from the AC port should meet the condition that the voltage of one pole is greater than zero and the voltage of the other pole is less than zero.

[0031] The function of the module open-loop wave generation test instruction is to perform an open-loop wave generation test on the module. The insulated gate bipolar transistor IGBT in the H-bridge is driven to turn on and off by the preset drive waveform, and then it is judged whether the waveform displayed by the oscilloscope from the AC port conforms to the on-off timing of each IGBT in the H-bridge. If it conforms, it indicates that the insulated gate bipolar transistor IGBT, capacitor and other components in the power module are working properly.

[0032] The function of the module voltage sampling test instruction is to sample and test the status quantities such as the voltage, temperature, and current of the power module. When the status quantity is not within the set range, a fault will be displayed on the display screen, and it can be verified whether the sampling of the power module is accurate.

[0033] The tester can judge the working condition of the power module and the specific position where the fault occurs through the display screen.

[0034] In particular, for the collected value of the status quantity displayed on the display screen, the tester can independently determine whether a fault occurs according to whether the status quantity exceeds the corresponding set range.

[0035] In particular, the AD sampling board reads the voltage value from the power supply circuit and sends it to the main control board. The main control board performs a difference operation on the voltage value collected by the AD sampling board and the voltage value detected from the power module to be tested. If the voltage difference exceeds the preset range, a fault will be displayed on the display screen.

[0036] During formal testing, after closing the switch to power on the power module automatic test device and the power module to be tested normally, control instructions can be sent through the display screen to perform tests such as input / output test and open-loop wave generation test, and the test results are displayed on the display screen. Whether it is the routine test of the in-plant power module or the stability test and fault location of the power module before the equipment is connected to the grid at the engineering site, this automatic test device can test various test contents such as the software and hardware of the power module without disassembling the power module, reducing the complexity of the power module test, improving the operation stability of the power module and the on-site fault repair efficiency, and reducing the input cost.

[0037] The above is only a preferred embodiment of the present invention and is not intended to limit the present invention. The patent protection scope of the present invention is subject to the claims. All equivalent structural changes made by using the content of the specification and drawings of the present invention should be included in the protection scope of the present invention by the same token.

Claims

1. An automatic test device for power modules of an H-bridge cascade high-voltage energy storage system, characterized in that: The invention comprises a power supply circuit connected to a test power supply output interface and an oscilloscope connected to an AC waveform input interface, wherein the test power supply output interface is used to connect to a battery port of a power module under test to provide a test power supply, and the AC waveform input interface is used to connect to an AC port of the power module under test; the invention also comprises a main control board, an interactive module connected to the main control board, and a power supply module for supplying power to the test device; the main control board is used to connect to a module control board of the power module under test through a communication interface to send control instructions and receive status information of the power module under test; the interactive module is used to input test instructions and display the status information.

2. The power module automatic testing device of the H-bridge cascade type high-voltage energy storage system according to claim 1 is characterized in that: It also includes an AC interface for connecting to the mains, and the other end of the power supply circuit is connected to the AC interface; a step-up transformer is provided in the power supply circuit, and a rectifier circuit is provided between the secondary winding of the step-up transformer and the test power supply output interface.

3. The power module automatic testing device of the H-bridge cascade type high-voltage energy storage system according to claim 2 is characterized in that: The rectifier circuit includes a diode connected in series to a line connected to a primary level of a secondary winding of a transformer and a capacitor and a resistor connected in parallel to a test power supply output interface, and the conduction direction of the diode points to the test power supply output interface.

4. The power module automatic testing device of the H-bridge cascade type high-voltage energy storage system according to claim 2 is characterized in that: An inductor is connected in series to one pole of the secondary winding of the transformer, and a fuse for protecting the power module under test is connected in series to the other pole.

5. The power module automatic testing device of the H-bridge cascade type high-voltage energy storage system according to claim 1 is characterized in that: It also includes a sampling module, which is used to collect the voltage value in the power supply circuit and send it to the main control board; It also includes an interface board for photoelectric conversion, the communication interface is an optical fiber interface, and the main control board is connected to the optical fiber interface and the sampling module through the interface board.

6. The power module automatic testing device of the H-bridge cascade type high-voltage energy storage system according to claim 5 is characterized in that: The power supply module includes a first switching power supply and a second switching power supply. The first switching power supply is used to supply power to the main control board and the interactive module respectively, and the second switching power supply is used to supply power to the sampling module.

7. The power module automatic testing device of the H-bridge cascade type high-voltage energy storage system according to claim 2 is characterized in that: The power module draws power from a power supply circuit between the AC interface and the primary winding of the step-up transformer.

8. The power module automatic testing device of the H-bridge cascade type high-voltage energy storage system according to claim 7 is characterized in that: A first circuit breaker is also provided on the power supply circuit between the AC interface and the primary winding of the step-up transformer; and a second circuit breaker is also provided between the secondary winding of the transformer and the battery port.

Images