Electrical life and short circuit experiment control system compatible with multi-standard alternating current charging pile

Abstract

The invention discloses an alternating current charging pile electrical life and short circuit experiment control system compatible with multiple standards, which comprises a PLC-touch screen all-in-one machine, a surge current simulation module, a conduction control module, a pole number voltage adaptation module, a data acquisition module and a circuit protection module, the PLC-touch screen all-in-one machine is respectively connected with the surge current simulation module, the conduction control module, the data acquisition module and the circuit protection module through signal lines, and the pole number voltage adaptation module is connected to the surge current simulation module, so that the strict requirements of national standards and international standards on the electrical life and short circuit experiments of the charging pile can be met; the device is suitable for charging piles with different pole numbers and voltage grades, achieves the precise control and protection of a charging pile experiment, and supports the safety compliance detection of the charging pile.

Description

Technical Field

[0001] This invention relates to the field of charging equipment testing technology, and in particular to a control system for electrical life and short circuit testing of AC charging piles compatible with multiple standards. Background Technology

[0002] With the rapid rise of the electric vehicle industry, AC charging piles, as one of the core supporting equipment for electric vehicles, have seen their application scale continuously expand. They are not only widely distributed in public charging stations, but also occupy the entire market for home electric vehicle charging piles, with highly widespread usage scenarios. However, the users of home AC charging piles are mainly non-electrical professionals, and the usage environment is relatively concentrated. Once the charging pile fails to protect itself, it is very easy to cause safety accidents such as electric shock, short circuit fire, etc. More seriously, the power source of electric vehicles is the battery pack, and short circuit explosion accidents are difficult to control through conventional fire-fighting measures, which can easily lead to the expansion of the fault and cause significant safety hazards.

[0003] To ensure the safe use of AC charging piles, strict mandatory testing standards have been successively formulated both domestically and internationally. Domestically, GB / T40820 "DC Residual Current Tester for Electric Vehicles Mode 3 Charging (RDC-DD)" serves as the core standard, clearly defining the testing requirements for key performance aspects such as electrical life and short-circuit testing of charging piles. For example, the electrical life test requires achieving a peak current of 200A±10A within 20μs, followed by a drop to 66A±3A within 30-50μs, repeated 2000 times with a 15s interval between tests. The short-circuit test includes four sub-clauses: rated connecting and breaking capacity, and the coordination of rated limiting short-circuit current. Internationally, standards such as CBTL and UL must be met, and these standards have significantly different parameter requirements for testing equipment, placing extremely high demands on the compatibility of the testing equipment.

[0004] However, the current market for specialized testing equipment for AC charging piles has significant shortcomings, particularly the lack of a fully compatible testing control system that meets the requirements of multiple standards and models. Existing control methods struggle to achieve stringent dynamic current simulations. For example, electrical life tests require the simulation of the entire surge current "peak-to-fallback" process within a maximum of 70μs, necessitating precise control of the current peak, fallback rate, and effective values ​​during the stable phase. Conventional equipment cannot meet the microsecond-level dynamic response and precision control requirements. AC charging piles encompass different structures such as two-pole, three-pole, and four-pole, with voltage levels ranging from 120V to 400V. The experimental adjustment parameters for different models vary greatly, and existing equipment cannot perform universal testing for multiple charging pile models. Individual equipment configurations are required for each model, resulting in high costs and low efficiency. Connecting a charging pile requires sequentially fulfilling a series of procedures, including self-testing, CP pre-charging condition detection, and charging start signal triggering. Furthermore, national standards, CBTL, and UL standards have different requirements for the values ​​of the CP signal and charging start signal. Some charging piles even exhibit reversed signal sequences. Existing equipment cannot accurately identify and simulate these differentiated signals, leading to experimental failures or distorted test results.

[0005] In summary, existing technologies cannot meet the experimental requirements of multi-standard adaptation, multi-model compatibility, and complex parameter control for AC charging piles. There is currently no special experimental control equipment on the market that can cover multiple standards, adapt to all models of charging piles, and meet microsecond-level precision control. This makes it difficult to support the compliance testing of charging pile products and has become a key bottleneck restricting the safe development of the charging pile industry. Therefore, a multi-standard AC charging pile electrical life and short-circuit test control system is proposed to solve the above-mentioned technical problems. Summary of the Invention

[0006] The purpose of this invention is to solve the above-mentioned technical problems and provide a control system for the electrical life and short circuit test of AC charging piles that is compatible with multiple standards. This invention can meet the stringent requirements of national and international standards for the electrical life and short circuit test of charging piles, adapt to charging piles with different pole numbers and voltage levels, realize precise control and protection of charging pile tests, and support the safety and compliance testing of charging piles.

[0007] The technical solution adopted by the present invention to solve the above-mentioned technical problems is: a multi-standard AC charging pile electrical life and short circuit test control system, including a PLC-touch screen all-in-one machine, a surge current simulation module, a conduction control module, a pole number voltage adaptation module, a data acquisition module and a circuit protection module. The PLC-touch screen all-in-one machine is connected to the surge current simulation module, the conduction control module, the data acquisition module and the circuit protection module through signal lines, and the pole number voltage adaptation module is connected to the surge current simulation module. The PLC-touchscreen all-in-one machine includes an operation interface and a data transmission module. The operation interface is used by the operator to set and view the data and experimental status that need to be used, and the data transmission module is used to transmit the instructions sent by the operator and receive the signals fed back by the receiving module. The surge current simulation module includes a large-capacity capacitor, a front-stage impedance adjustment resistor group R1-R9, a 1C contactor, and a 2C contactor. The 1C contactor is used for switching the main circuit, and the 2C contactor is used for the capacitor discharge circuit. The surge current simulation module is used to simulate the surge current of 200A±10A in the electrical life and short circuit test control system of the multi-standard AC charging pile at the moment of connection of the charging pile, and the current waveform that drops back to 66A±3A within 30-50μs. The conduction control module includes K1 contact, K2 contact, adjustable resistors R13 and R14, diode D1 and PE ground. The conduction control module is used to simulate CP pre-charge signal and charging start signal. The pole number voltage adapter module includes a 3C contactor, a 4C contactor, a 5C contactor, and a downstream impedance resistor group R10-R12. The 3C contactor is used for three / four pole switching, the 4C contactor is used for three-phase circuit switching, and the 5C contactor is used for impedance adjustment. The pole number voltage adapter module can adapt to two / three / four pole charging piles and 120V / 230V / 240V / 400V voltage levels, and match different current parameters. The data acquisition module includes an analog channel, a digital channel, and an analog transmitter, used to collect parameters during the experiment and compare them with preset thresholds; The circuit protection module includes main circuit breakers HK1-HK3, which are used to control the overall on / off state of the experiment; An experimental method for a multi-standard AC charging pile electrical life and short-circuit test control system, characterized by the following steps: S1: System initialization and parameter configuration, completing the hardware status check and software parameter preset of the experimental system; S2: Simulate the preconditions for charging pile to be turned on, identify the charging pile self-test signal, and send the CP pre-charging simulation signal and the charging start simulation signal to ensure that the charging pile meets the turn-on requirements; S3: Select the type of experiment to be performed, including one of the following: continuity test, short circuit test, or connection test. During the experiment, current, voltage, and charging pile status data are collected in real time. S4: Compare the data collected in step S3 with the preset threshold. If an abnormality is found, activate the protection system, cut off the experimental circuit and issue an alarm. S5: After completing a single experiment, reset the experimental system. If multiple cycles are required, repeat steps S2-S4 until the preset number of experiments is reached and an experimental data report is generated.

[0008] Preferably, the main circuit of the surge current simulation module consists of a main circuit breaker HK1-HK3, a resistor group R1-R9, a large-capacity capacitor, an IC contactor, and a charging pile current input terminal. The discharge circuit of the surge current simulation module consists of a large-capacity capacitor, a 2C contactor, an R10-R12 resistor group, and a PE. During the surge phase, the main circuit and the discharge circuit close the 1C contactor and open the 2C contactor. After the current drops back to 66A, the 1C contactor is opened and the circuit switches to the subsequent impedance circuit.

[0009] Preferably, the CP signal circuit of the conduction control module consists of PLC output, K1 contact, R14 adjustable resistor, D1 diode, charging pile CP terminal, and PE; The charging start signal circuit of the conduction control module consists of PLC output, K2 contact, R13 adjustable resistor, charging start terminal of charging pile, and PE; When the K1 and K2 contacts are interchanged, the signal output sequence is switched via the PLC.

[0010] Preferably, the pole number voltage adapter module disconnects the 3C / 4C contactor and directly connects the main circuit when connecting a two-pole charging pile; when connecting a three-pole charging pile, it closes the 3C contactor to switch the three-phase current channel; and when connecting a four-pole charging pile, it closes the 3C / 4C contactor simultaneously. The voltage adapter module adjusts the circuit voltage from 120V to 400V by connecting the 5C contactor and the number of R1-R12 resistors.

[0011] Preferably, the circuit protection module includes a primary protection circuit: data acquisition module, PLC, 1C / 2C contactor disconnection, cutting off the experimental circuit, and fault light illumination; The circuit protection module includes a two-stage protection circuit: a data acquisition module, a PLC, a laboratory protection system, HK1-HK3 disconnection, and fault recording.

[0012] Preferably, the system initialization and parameter configuration in step S1 specifically includes: S11: Confirm that the residual voltage of the large-capacity capacitor in the experimental system meets the initial requirements, ensure that the 1C-5C contactors are in the open state, and ensure that the R1-R14 high-power resistors and adjustable resistors are connected normally. S12: Select the target experiment type as continuity test / short circuit test / connection test on the PLC-touch screen all-in-one machine; S13: Input the key parameters required for the experiment, select the charging type, and the corresponding number of charging pile poles: two-pole / three-pole / four-pole; voltage level: 120V / 230V / 240V / 400V; set the experimental time base, such as 10ms / 100ms, as needed; switch between remote / local modes. In local mode, operate the all-in-one machine directly; in remote mode, confirm that the remote control signal is normal; confirm the sample monitoring function.

[0013] Preferably, the preconditions for activating the simulated charging pile in step S2 specifically include: S21: The experimental system receives the self-test pass signal after the charging pile is powered on. If it is not detected, a fault alarm is triggered. S22: CP pre-charge analog signal is sent, K1 contact is closed, and PE is connected through adjustable resistor R14 and diode D1 to output CP signal. Signal difference compensation is achieved by adjusting the resistance value of R14. S23: After the system detects that the CP signal is normal, it closes the K2 contact, connects to PE through the adjustable resistor R13, and sends a charging start signal; S24: When the CP signal and the charging start signal of the charging pile are reversed, the K1K2 swap function on the system touch screen is triggered to adjust the sending order of the two signals, and the charging pile is connected normally.

[0014] Preferably, the on / off test in step S3 specifically includes: S311: The system controls the large-capacity capacitor to be connected to the experimental circuit. Utilizing the capacitor's DC blocking and AC passing characteristics, the peak current reaches 200A±10A within 20μs of the moment of connection. At the same time, the impedance of the preceding stage is limited by adjusting the high-power resistors R1-R9 to ensure that the peak current meets the preset requirements. S312: After the capacitor is energized, as the charge accumulates, the current naturally drops back to 66A±3A within 30-50μs. At this time, because the resistance of the capacitor circuit is much smaller than the impedance of the subsequent stage of the experimental system, the current shunting error is controlled within the allowable range. S313: After the current drops back to the target value, disconnect the 1C contactor to switch the charging pile current channel to the subsequent impedance circuit, maintain the effective value of the experimental current and keep it for 2s±100ms. S314: After the power-on time reaches the specified standard, the internal contacts of the driving charging pile will be disconnected, and the capacitor discharge circuit of the 2C contactor will be connected to discharge and reset the capacitor. S315: Repeat steps S311-S314 after a 15-second interval until the set number of cycles is completed. During the experiment, current, voltage and charging pile status data are collected in real time through 4 analog channels and 2 digital channels in the data acquisition area.

[0015] Preferably, the short-circuit test in step S3 specifically includes: S321: After the charging pile is turned on, the external short-circuit device is closed, the short-circuit current is adjusted, the short-circuit process is monitored, and the short-circuit current value, short-circuit duration and coordination parameters between the charging pile and the external short-circuit device are collected in real time through the data acquisition area and compared with the preset threshold. S322: If the short-circuit current exceeds the protection range of the experimental system itself, immediately send a trigger signal to the highest level protection system in the laboratory to cut off the main power supply to the experiment.

[0016] Preferably, the connection experiment in step S3 specifically includes: S331: Controls the connection of a large-capacity capacitor to the circuit, so that the peak current reaches 200A±10A within 20μs and drops back to 66A±3A within 30-50μs, and monitors the current waveform in real time in the data acquisition area to see if it meets the standard. S332: After the initial connection, there is no need to repeatedly send the CP pre-charge simulation signal. The connection and disconnection of the charging pile can be achieved simply by triggering the K2 contact to send the charging start signal. S333: Data recording. Record parameters such as peak current, fallback time, and connection duration during each connection process. If the data is abnormal during a single connection, the experiment will be paused and an alarm will be triggered.

[0017] The beneficial effects of this invention are: 1. This invention can solve the current market's extreme lack of fully compatible special testing equipment that can meet the multi-standard and complex experimental requirements of AC charging piles, and provide key equipment for the compliance testing of charging piles; 2. This invention adapts to the signal requirements of different standards by adjusting the resistor, and switches between two-pole, three-pole, four-pole and 120V-400V charging piles by contactor, without the need for separate equipment configuration. 3. Based on the PLC-touch screen all-in-one machine, the experimenters only need to set a few key parameters, and the system can automatically identify the charging pile status and complete the experimental process. The whole process does not require supervision, and it can also detect abnormalities and protect against them. 4. The system monitors the experimental status in real time through multi-channel data acquisition, can be linked to the highest level of laboratory protection system, and has a high-precision hidden protection function for authorized access to avoid experimental risks. Attached Figure Description

[0018] Figure 1 This is the experimental control principle diagram of the main circuit of the present invention; Figure 2 This is an experimental control principle diagram of the conduction circuit of the present invention; Figure 3 This is a schematic diagram of the main interface of the PLC-touchscreen all-in-one machine of the present invention; Figure 4This is a schematic diagram of the test function selection interface of the experimental control system of the present invention; Figure 5 This is a schematic diagram of the on / off experimental interface of the experimental control system of the present invention; Figure 6 This is a schematic diagram of the experimental control area of ​​the present invention; Figure 7 This is a schematic diagram of the data acquisition module of the present invention; Figure 8 This is a schematic diagram of the circuit protection module of the present invention; Figure 9 This is a schematic diagram of the function selection area of ​​the present invention; Figure 10 This is a schematic diagram of the magnification selection interface of the present invention; Figure 11 This is a diagram of the short-circuit test standard clause of the present invention; Figure 12 This is the electrical life test current waveform diagram required for the instantaneous connection of the present invention; Figure 13 This is a preferred diagram showing the charging pile type and rated voltage of the present invention.

[0019] In the diagram: 1. PLC-Touchscreen All-in-One Machine, 2. Surge Current Simulation Module, 3. Conduction Control Module, 4. Pole Number Voltage Adaptation Module, 5. Data Acquisition Module, 6. Circuit Protection Module. Detailed Implementation

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0021] like Figure 1-13 As shown, the present invention provides a multi-standard AC charging pile electrical life and short circuit test control system, including a PLC-touch screen all-in-one machine 1, a surge current simulation module 2, a conduction control module 3, a pole number voltage adaptation module 4, a data acquisition module 5, and a circuit protection module 6. The PLC-touch screen all-in-one machine 1 is connected to the surge current simulation module 2, the conduction control module 3, the data acquisition module 5, and the circuit protection module 6 through signal lines, and the pole number voltage adaptation module 4 is connected to the surge current simulation module 2. The PLC-touchscreen all-in-one machine 1 includes an operation interface and a data transmission module. The operation interface is used by the operator to set and view the data and experimental status that need to be used, and the data transmission module is used to transmit the instructions sent by the operator and receive the signals fed back by the receiving module. The surge current simulation module 2 includes a large-capacity capacitor, a front-stage impedance adjustment resistor group R1-R9, a 1C contactor, and a 2C contactor. The 1C contactor is used for switching the main circuit, and the 2C contactor is used for the capacitor discharge circuit. The surge current simulation module 2 is used to simulate the surge current of 200A±10A in the control system of the electrical life and short circuit test of the multi-standard AC charging pile at the moment of connection of the charging pile, and the current waveform that drops back to 66A±3A within 30-50μs. The conduction control module 3 includes K1 contact, K2 contact, adjustable resistors R13 and R14, diode D1 and PE ground. The conduction control module 3 is used to simulate CP pre-charge signal and charging start signal. The pole number voltage adapter module 4 includes a 3C contactor, a 4C contactor, a 5C contactor, and a downstream impedance resistor group R10-R12. The 3C contactor is used for three / four pole switching, the 4C contactor is used for three-phase circuit switching, and the 5C contactor is used for impedance adjustment. The pole number voltage adapter module 4 can adapt to two / three / four pole charging piles and 120V / 230V / 240V / 400V voltage levels, and match different current parameters. Data acquisition module 5 includes analog channels, digital channels and analog transmitters, used to collect parameters during the experiment and compare them with preset thresholds; The circuit protection module 6 includes main circuit breakers HK1-HK3, which are used to control the overall on / off state of the experiment; An experimental method for a multi-standard AC charging pile electrical life and short-circuit test control system, characterized by the following steps: S1: System initialization and parameter configuration, completing the hardware status check and software parameter preset of the experimental system; S2: Simulate the preconditions for charging pile to be turned on, identify the charging pile self-test signal, and send the CP pre-charging simulation signal and the charging start simulation signal to ensure that the charging pile meets the turn-on requirements; S3: Select the type of experiment to be performed, including one of the following: continuity test, short circuit test, or connection test. During the experiment, current, voltage, and charging pile status data are collected in real time. S4: Compare the data collected in step S3 with the preset threshold. If an abnormality is found, activate the protection system, cut off the experimental circuit and issue an alarm. S5: After completing a single experiment, reset the experimental system. If multiple cycles are required, repeat steps S2-S4 until the preset number of experiments is reached and an experimental data report is generated.

[0022] By linking multiple modules through the PLC-touch screen all-in-one machine, the problems of traditional experimental equipment being scattered and complex to operate are solved. Experimenters only need to set key parameters to automatically complete the experiment, which greatly reduces the operating threshold. Supports continuity / short circuit / connection tests, automatically cycles to the preset number of times and generates a report, meeting all the requirements of multiple standards such as GB / T40820, CBTL, and UL for the electrical life and short circuit test of charging piles, and meeting the needs of fully compatible equipment; Data is collected in real time during the experiment and compared with the threshold. In case of abnormality, protection is automatically activated to avoid risks such as electric shock, short circuit and fire.

[0023] Before the experiment, ensure that there is no poor contact between the PLC and the signal lines of the surge current simulation and conduction control modules to avoid instruction delays or loss. According to the number of charging pile poles (two / three / four poles), voltage level (120V / 230V / 240V / 400V) and experiment type, accurately input the key parameters to avoid experimental data distortion or equipment damage due to parameter mismatch. After each experiment, confirm that the capacitor has discharged completely and the contactor has been reset before starting the next cycle to prevent residual voltage from affecting the experimental accuracy.

[0024] The main circuit of surge current simulation module 2 consists of main circuit breaker HK1-HK3, resistor group R1-R9, large-capacity capacitor, IC contactor, and charging pile current input terminal. The discharge circuit of surge current simulation module 2 consists of a large-capacity capacitor, a 2C contactor, an R10-R12 resistor group, and a PE. During the surge phase, the main circuit and the discharge circuit close the 1C contactor and open the 2C contactor. After the current drops to 66A, the 1C contactor is opened and the circuit switches to the subsequent impedance circuit.

[0025] By utilizing the DC blocking and AC passing characteristics of a large-capacity capacitor, a peak current of 200A±10A within 20μs and a drop back to 66A±3A within 30-50μs can be achieved, meeting the microsecond-level control requirements of electrical life tests. The main circuit and the discharge circuit are controlled by 1C contactor / 2C contactor timing to avoid current interruption or sudden change and ensure the continuous and stable experimental process. The discharge current is limited by resistors R10-R12 to prevent capacitor damage due to over-discharge and extend the module's lifespan.

[0026] During the surge phase, select a large-capacity capacitor with low residual voltage and fast charging and discharging speed to ensure that the current rise rate during the surge phase meets the standard. During the surge phase, strictly keep 1C closed and 2C open. After the current drops back to 66A, immediately switch the 1C / 2C state. The timing error needs to be controlled in the microsecond level and can be calibrated through the PLC program. Use high-power resistors R1-R9 to avoid the resistors overheating and burning out due to the 200A peak current.

[0027] The CP signal circuit of the conduction control module 3 consists of PLC output, K1 contact, R14 adjustable resistor, D1 diode, charging pile CP terminal, and PE; The charging start signal circuit of the conduction control module 3 consists of PLC output, K2 contact, R13 adjustable resistor, charging start terminal of charging pile, and PE; When K1 and K2 contacts are interchanged, the PLC switches the signal output sequence.

[0028] The adjustable resistors R13 / R14 compensate for signal differences, adapting to different numerical requirements of standard signals and charging start signals without replacing hardware; the PLC switches the K1 / K2 contact sequence to adapt to the special case where the CP signal and charging start signal of some charging piles are reversed, improving system compatibility; PE grounding avoids signal interference, ensuring stable transmission of analog signals and preventing problems such as charging piles failing to conduct due to signal abnormalities.

[0029] When connecting to a two-pole charging pile, the pole number voltage adapter module 4 disconnects the 3C / 4C contactor and directly connects the main circuit; when connecting to a three-pole charging pile, it closes the 3C contactor and switches the three-phase current channel; when connecting to a four-pole charging pile, it closes the 3C / 4C contactor at the same time. The number of poles voltage adapter module 4 adjusts the circuit voltage from 120V to 400V by connecting the number of 5C contactors and R1-R12 resistors.

[0030] The combination of 3C / 4C contactors enables rapid switching between two / three / four pole charging stations, eliminating the need for separate experimental circuits for each pole number. The 5C contactor controls the number of R1-R12 resistors connected, adapting to voltage levels from 120V to 400V to meet the experimental needs of charging stations in different regions. This avoids the need to repeatedly purchase experimental equipment due to differences in charging station models / voltages.

[0031] When connecting a three-pole charging station, only close 3C; when connecting a four-pole charging station, close both 3C and 4C simultaneously to avoid short circuits caused by misoperation. Based on the target voltage, control the number of R1-R12 connection groups through the 5C contactor to ensure that the circuit impedance matches the voltage and prevent current overload. When changing the number of charging station poles or voltage level, the main power supply of HK1-HK3 must be disconnected first, and then the contactor status must be adjusted.

[0032] Circuit protection module 6 includes a primary protection circuit: data acquisition module 5, PLC, 1C / 2C contactor disconnection, cutting off the experimental circuit, and fault light illumination; The circuit protection module 6 includes a two-stage protection circuit: data acquisition module 5, PLC, laboratory protection system, disconnection of HK1-HK3, and fault recording.

[0033] The first-level protection disconnects the experimental circuit quickly and disconnects the 1C / 2C contactor to deal with minor abnormalities; the second-level protection links the highest-level system of the laboratory to disconnect the main power supply HK1-HK3 to deal with serious faults, such as excessive short-circuit current, and prevents the fault from escalating. The secondary protection system records fault information synchronously, which facilitates subsequent troubleshooting by laboratory personnel. By processing the feedback signals from the data acquisition module in real time using a PLC, the delay of the protection action is controlled within milliseconds, thus preventing equipment damage.

[0034] Step S1, system initialization and parameter configuration, specifically includes: S11: Confirm that the residual voltage of the large-capacity capacitor in the experimental system meets the initial requirements, ensure that the 1C-5C contactors are in the open state, and ensure that the R1-R14 high-power resistors and adjustable resistors are connected normally. S12: Select the target experiment type as continuity test / short circuit test / connection test on PLC-touch screen all-in-one machine 1; S13: Input the key parameters required for the experiment, select the charging type, and the corresponding number of charging pile poles: two-pole / three-pole / four-pole; voltage level: 120V / 230V / 240V / 400V; set the experimental time base, such as 10ms / 100ms, as needed; switch between remote / local modes. In local mode, operate the all-in-one machine directly; in remote mode, confirm that the remote control signal is normal; confirm the sample monitoring function.

[0035] By checking residual capacitor voltage, contactor status, etc., ensure that the system has no initial faults and avoid deviation from the experimental starting point; Non-critical parameters are fixed, requiring only input of 6 key parameters such as number of poles, voltage, and number of experiments, reducing the difficulty of operation for non-professionals; Remote / local mode switching meets different needs for local laboratory operation or remote monitoring.

[0036] The initial state check fully confirms that the residual voltage of the capacitor is less than or equal to the preset value, all contactors 1C-5C are disconnected, and resistors R1-R14 are not loose. Select the corresponding parameters according to the number of poles and voltage level of the charging pile. Before remote control, it is necessary to confirm that the communication between the PLC and the remote terminal is normal and send test commands to verify the effectiveness of the control.

[0037] The specific preconditions for simulating the charging pile to be connected in step S2 include: S21: The experimental system receives the self-test pass signal after the charging pile is powered on. If it is not detected, a fault alarm is triggered. S22: CP pre-charge analog signal is sent, K1 contact is closed, and PE is connected through adjustable resistor R14 and diode D1 to output CP signal. Signal difference compensation is achieved by adjusting the resistance value of R14. S23: After the system detects that the CP signal is normal, it closes the K2 contact, connects to PE through the adjustable resistor R13, and sends a charging start signal; S24: When the CP signal and the charging start signal of the charging pile are reversed, the K1K2 swap function on the system touch screen is triggered to adjust the sending order of the two signals, and the charging pile is connected normally.

[0038] First, the self-test signal is identified, and then the analog signal is sent. This conforms to the conduction logic of charging pile self-test → pre-charging → charging, thus avoiding experimental start-up failure. The K1K2 interchange function is used to adapt to charging piles with reversed signals, improving system compatibility. An alarm will sound immediately if no self-test signal is detected to prevent damage to the charging pile from forced start of the experiment.

[0039] The PLC collects the self-test signal fed back by the charging pile to confirm that the signal amplitude and frequency meet the requirements. The CP signal is adjusted to the receiving range of the charging pile through R14 to avoid the charging pile refusing to conduct due to the signal being too strong or too weak. The CP pre-charging signal is sent first, and the charging start signal is sent after the charging pile is detected to be ready.

[0040] The on / off experiment in step S3 specifically includes: S311: The system controls the large-capacity capacitor to be connected to the experimental circuit. Utilizing the capacitor's DC blocking and AC passing characteristics, the peak current reaches 200A±10A within 20μs of the moment of connection. At the same time, the impedance of the preceding stage is limited by adjusting the high-power resistors R1-R9 to ensure that the peak current meets the preset requirements. S312: After the capacitor is energized, as the charge accumulates, the current naturally drops back to 66A±3A within 30-50μs. At this time, because the resistance of the capacitor circuit is much smaller than the impedance of the subsequent stage of the experimental system, the current shunting error is controlled within the allowable range. S313: After the current drops back to the target value, disconnect the 1C contactor to switch the charging pile current channel to the subsequent impedance circuit, maintain the effective value of the experimental current and keep it for 2s±100ms. S314: After the power-on time reaches the specified standard, the internal contacts of the driving charging pile will be disconnected, and the capacitor discharge circuit of the 2C contactor will be connected to discharge and reset the capacitor. S315: Repeat steps S311-S314 after a 15-second interval until the set number of cycles is completed. During the experiment, current, voltage and charging pile status data are collected in real time through 4 analog channels and 2 digital channels in the data acquisition area.

[0041] It accurately reproduces the surge → fall back → stabilize → discharge process of 2000 cycles, meeting the requirements of GB / T40820: 20μs peak, 30-50μs fall back, 2s stabilization, and 15s interval. The system simultaneously acquires current, voltage, and charging pile status through 4 analog and 2 digital input channels, ensuring complete experimental data and enabling 2000 cycles to be completed without manual intervention, significantly improving experimental efficiency.

[0042] Adjust the preamp impedance using R1-R9 to ensure the peak current stabilizes at 200A±10A within 20μs. If the error exceeds the limit, the resistors need to be recalibrated. After the current drops back to 66A, maintain a stable time of 2s±100ms. Use the PLC timer for precise control. After each cycle, connect the discharge circuit via the 2C contactor to ensure that the residual voltage of the capacitor drops to the initial value, thus avoiding affecting the accuracy of the next surge current.

[0043] The short-circuit test in step S3 specifically includes: S321: After the charging pile is turned on, the external short-circuit device is closed, the short-circuit current is adjusted, the short-circuit process is monitored, and the short-circuit current value, short-circuit duration and coordination parameters between the charging pile and the external short-circuit device are collected in real time through the data acquisition area and compared with the preset threshold. S322: If the short-circuit current exceeds the protection range of the experimental system itself, immediately send a trigger signal to the highest level protection system in the laboratory to cut off the main power supply to the experiment.

[0044] It meets the requirements of four sub-clauses in GB / T40820, including rated breaking capacity and coordination of short-circuit current limiting, without the need for additional equipment; Real-time monitoring of short-circuit current; if it exceeds the system protection range, immediately link the laboratory system to cut off the main power supply to prevent major accidents such as deflagration. Record the short-circuit current value, duration, and coordination parameters to provide a basis for evaluating the short-circuit performance of charging piles.

[0045] The system is linked to the external short-circuit device, and the short-circuit action and data acquisition are started synchronously to avoid data lag. According to the preset rated limit of short-circuit current Iw, if it is exceeded, the secondary protection is immediately triggered. After the short-circuit test is completed, check whether the charging pile contacts are burned or whether the test circuit is damaged. The next test is carried out only after confirming that there are no faults.

[0046] The connection experiment in step S3 specifically includes: S331: Controls the connection of a large-capacity capacitor to the circuit, so that the peak current reaches 200A±10A within 20μs and drops back to 66A±3A within 30-50μs, and monitors the current waveform in real time in the data acquisition area to see if it meets the standard. S332: After the initial connection, there is no need to repeatedly send the CP pre-charge simulation signal. The connection and disconnection of the charging pile can be achieved simply by triggering the K2 contact to send the charging start signal. S333: Data recording. Record parameters such as peak current, fallback time, and connection duration during each connection process. If the data is abnormal during a single connection, the experiment will be paused and an alarm will be triggered.

[0047] After the initial connection, there is no need to send the CP signal repeatedly. Only the charging start signal needs to be triggered to complete the connection and disconnection, thus improving experimental efficiency. Real-time monitoring is conducted to ensure that the current waveform meets the requirements of a 20μs peak value and a 30-50μs fall-off, in order to avoid unqualified waveforms affecting the experimental results. If a single connection fails and data is abnormal, the experiment should be immediately paused to prevent the accumulation of faults from damaging the charging station.

[0048] For the first test, ensure that the CP signal is normal. When subsequent connection depends only on the charging start signal, confirm that the charging pile memory function is normal. Record the current peak, fall-off time and connection duration for each connection to facilitate subsequent analysis of the charging pile connection performance. Set the peak value exceeding 200A±10A or the fall-off time exceeding 50μs as the abnormal standard. After triggering the alarm, check for resistor or capacitor faults.

[0049] The various embodiments in the specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0050] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A control system for electrical life and short-circuit testing of multi-standard AC charging piles, characterized in that: The system includes a PLC-touch screen all-in-one machine (1), a surge current simulation module (2), a conduction control module (3), a pole number voltage adaptation module (4), a data acquisition module (5), and a circuit protection module (6). The PLC-touch screen all-in-one machine (1) is connected to the surge current simulation module (2), the conduction control module (3), the data acquisition module (5), and the circuit protection module (6) through signal lines. The pole number voltage adaptation module (4) is connected to the surge current simulation module (2). The PLC-touch screen all-in-one machine (1) includes an operation interface and a data transmission module. The operation interface is used by the operator to set and view the data and experimental status that need to be used. The data transmission module is used to transmit the instructions sent by the operator and the signals fed back by the receiving module. The surge current simulation module (2) includes a large-capacity capacitor, a front-stage impedance adjustment resistor group R1-R9, a 1C contactor and a 2C contactor. The 1C contactor is used for switching the main circuit, and the 2C contactor is used for the capacitor discharge circuit. The surge current simulation module (2) is used to simulate the surge current of 200A±10A in the electrical life and short circuit test control system of the charging pile at the moment of connection of the charging pile in 20μs, and the current waveform that drops back to 66A±3A within 30-50μs. The conduction control module (3) includes K1 contact, K2 contact, adjustable resistors R13 and R14, diode D1 and PE ground. The conduction control module (3) is used to simulate CP pre-charge signal and charging start signal. The pole number voltage adapter module (4) includes a 3C contactor, a 4C contactor, a 5C contactor and a downstream impedance resistor group R10-R12. The 3C contactor is used for three / four pole switching, the 4C contactor is used for three-phase circuit switching, and the 5C contactor is used for impedance adjustment. The pole number voltage adapter module (4) can adapt to two / three / four pole charging piles and 120V / 230V / 240V / 400V voltage levels, and match different current parameters. The data acquisition module (5) includes an analog channel, a digital channel and an analog transmitter, used to collect parameters during the experiment and compare them with preset thresholds; The circuit protection module (6) includes a main circuit breaker HK1-HK3 for controlling the overall on / off state of the experiment; An experimental method for a multi-standard AC charging pile electrical life and short-circuit test control system, characterized by the following steps: S1: System initialization and parameter configuration, completing the hardware status check and software parameter preset of the experimental system; S2: Simulate the preconditions for charging pile to be turned on, identify the charging pile self-test signal, and send the CP pre-charging simulation signal and the charging start simulation signal to ensure that the charging pile meets the turn-on requirements; S3: Select the type of experiment to be performed, including one of the following: continuity test, short circuit test, or connection test. During the experiment, current, voltage, and charging pile status data are collected in real time. S4: Compare the data collected in step S3 with the preset threshold. If an abnormality is found, activate the protection system, cut off the experimental circuit and issue an alarm. S5: After completing a single experiment, reset the experimental system. If multiple cycles are required, repeat steps S2-S4 until the preset number of experiments is reached and an experimental data report is generated.

2. The multi-standard AC charging pile electrical life and short-circuit test control system according to claim 1, characterized in that: The main circuit of the surge current simulation module (2) consists of the main circuit breaker HK1-HK3, resistor group R1-R9, large capacity capacitor, IC contactor, and charging pile current input terminal. The discharge circuit of the surge current simulation module (2) consists of a large-capacity capacitor, a 2C contactor, an R10-R12 resistor group, and a PE. During the surge phase, the main circuit and the discharge circuit close the 1C contactor and open the 2C contactor. After the current drops back to 66A, the 1C contactor is opened and the circuit switches to the subsequent impedance circuit.

3. The multi-standard AC charging pile electrical life and short-circuit test control system according to claim 1, characterized in that: The CP signal circuit of the conduction control module (3) consists of PLC output, K1 contact, R14 adjustable resistor, D1 diode, charging pile CP terminal, and PE. The charging start signal circuit of the conduction control module (3) consists of PLC output, K2 contact, R13 adjustable resistor, charging start terminal of charging pile, and PE; When the K1 and K2 contacts are interchanged, the signal output sequence is switched via the PLC.

4. The multi-standard AC charging pile electrical life and short-circuit test control system according to claim 1, characterized in that: When connecting a two-pole charging pile, the voltage adapter module (4) disconnects the 3C / 4C contactor and directly connects the main circuit; when connecting a three-pole charging pile, it closes the 3C contactor and switches the three-phase current channel; when connecting a four-pole charging pile, it simultaneously closes the 3C / 4C contactor. The voltage adapter module (4) adjusts the circuit voltage from 120V to 400V by connecting the 5C contactor and the R1-R12 resistors.

5. The multi-standard AC charging pile electrical life and short-circuit test control system according to claim 1, characterized in that, The circuit protection module (6) includes a primary protection circuit: data acquisition module (5), PLC, 1C / 2C contactor disconnection, cut-off of experimental circuit, and fault light illumination; The circuit protection module (6) includes a two-level protection circuit: data acquisition module (5), PLC, laboratory protection system, disconnection of HK1-HK3, and fault recording.

6. The experimental method for the multi-standard AC charging pile electrical life and short-circuit test control system according to claim 1, characterized in that, The system initialization and parameter configuration in step S1 specifically includes: S11: Confirm that the residual voltage of the large-capacity capacitor in the experimental system meets the initial requirements, ensure that the 1C-5C contactors are in the open state, and ensure that the R1-R14 high-power resistors and adjustable resistors are connected normally. S12: Select the target experiment type as continuity test / short circuit test / connection test on the PLC-touch screen all-in-one machine (1); S13: Input the key parameters required for the experiment, select the charging type, and the corresponding number of charging pile poles: two-pole / three-pole / four-pole; voltage level: 120V / 230V / 240V / 400V; set the experimental time base, such as 10ms / 100ms, as needed; switch between remote / local modes. In local mode, operate the all-in-one machine directly; in remote mode, confirm that the remote control signal is normal; confirm the sample monitoring function.

7. The experimental method for the multi-standard AC charging pile electrical life and short-circuit test control system according to claim 1, characterized in that, The specific preconditions for activating the simulated charging pile in step S2 include: S21: The experimental system receives the self-test pass signal after the charging pile is powered on. If it is not detected, a fault alarm is triggered. S22: CP pre-charge analog signal is sent, K1 contact is closed, and PE is connected through adjustable resistor R14 and diode D1 to output CP signal. Signal difference compensation is achieved by adjusting the resistance value of R14. S23: After the system detects that the CP signal is normal, it closes the K2 contact, connects to PE through the adjustable resistor R13, and sends a charging start signal; S24: When the CP signal and the charging start signal of the charging pile are reversed, the K1K2 swap function on the system touch screen is triggered to adjust the sending order of the two signals, and the charging pile is connected normally.

8. The experimental method for the multi-standard AC charging pile electrical life and short-circuit test control system according to claim 1, characterized in that, The on / off experiment in step S3 specifically includes: S311: The system controls the large-capacity capacitor to be connected to the experimental circuit. Utilizing the capacitor's DC blocking and AC passing characteristics, the peak current reaches 200A±10A within 20μs of the moment of connection. At the same time, the impedance of the preceding stage is limited by adjusting the high-power resistors R1-R9 to ensure that the peak current meets the preset requirements. S312: After the capacitor is energized, as the charge accumulates, the current naturally drops back to 66A±3A within 30-50μs. At this time, because the resistance of the capacitor circuit is much smaller than the impedance of the subsequent stage of the experimental system, the current shunting error is controlled within the allowable range. S313: After the current drops back to the target value, disconnect the 1C contactor to switch the charging pile current channel to the subsequent impedance circuit, maintain the effective value of the experimental current and keep it for 2s±100ms. S314: After the power-on time reaches the specified standard, the internal contacts of the driving charging pile will be disconnected, and the capacitor discharge circuit of the 2C contactor will be connected to discharge and reset the capacitor. S315: Repeat steps S311-S314 after a 15-second interval until the set number of cycles is completed. During the experiment, current, voltage and charging pile status data are collected in real time through 4 analog channels and 2 digital channels in the data acquisition area.

9. The experimental method for the multi-standard AC charging pile electrical life and short-circuit test control system according to claim 1, characterized in that, The short-circuit test in step S3 specifically includes: S321: After the charging pile is turned on, the external short-circuit device is closed, the short-circuit current is adjusted, the short-circuit process is monitored, and the short-circuit current value, short-circuit duration and coordination parameters between the charging pile and the external short-circuit device are collected in real time through the data acquisition area and compared with the preset threshold. S322: If the short-circuit current exceeds the protection range of the experimental system itself, immediately send a trigger signal to the highest level protection system in the laboratory to cut off the main power supply to the experiment.

10. The experimental method for the multi-standard AC charging pile electrical life and short-circuit test control system according to claim 1, characterized in that, The connection experiment in step S3 specifically includes: S331: Controls the connection of a large-capacity capacitor to the circuit, so that the peak current reaches 200A±10A within 20μs and drops back to 66A±3A within 30-50μs, and monitors the current waveform in real time in the data acquisition area to see if it meets the standard. S332: After the initial connection, there is no need to repeatedly send the CP pre-charge simulation signal. The connection and disconnection of the charging pile can be achieved simply by triggering the K2 contact to send the charging start signal. S333: Data recording. Record parameters such as peak current, fallback time, and connection duration during each connection process. If the data is abnormal during a single connection, the experiment will be paused and an alarm will be triggered.

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