Multi-interface compatible high-precision portable direct current charging pile testing device

Abstract

The application is suitable for the technical field of charging pile testing, and provides a multi-interface compatible high-precision portable direct-current charging pile testing device.The device comprises a main control module and a power supply switching module, a current detection module and a metering module connected with the main control module; the power supply switching module comprises a standby battery, a charging power taking unit and a switching unit; the main control module is configured to: after charging is started, the charging power taking unit is connected for power supply by the standby battery and the charging power taking unit; when the charging current is judged to be stable according to the current detection module, the standby battery is disconnected, and the charging power taking unit is powered and charged alone; when a test stop signal is detected, the standby battery is connected first, and the charging power taking unit is disconnected after a time delay.The application solves the problems that the existing tester needs external power supply and load and has short endurance, and realizes super-long endurance, high-precision metering and multi-interface compatibility.

Description

Technical Field

[0001] This invention relates to the field of charging pile testing technology, and in particular to a high-precision portable DC charging pile testing device with multiple compatible interfaces. Background Technology

[0002] With the rapid development of the new energy vehicle industry, the popularity of DC charging piles is constantly increasing, and the demand for on-site metrology and testing is growing. At present, charging pile testers on the market usually adopt a solution of built-in small-capacity battery power supply to achieve portability, and an external load is required to complete the testing work.

[0003] However, due to the limited capacity of the built-in battery and the need for an external load during testing, the tester cannot work continuously for long periods of time in the outdoor field. Testers need to frequently interrupt the test to charge it or carry an additional outdoor power supply and load equipment, which reduces the efficiency and portability of on-site testing. Summary of the Invention

[0004] This invention provides a high-precision portable DC charging pile testing device with multiple compatible interfaces to solve the problem that existing testing instruments cannot balance portability and testing endurance.

[0005] In a first aspect, embodiments of this application provide a high-precision portable DC charging pile testing device with multiple interface compatibility, including: a main control module, and a power supply switching module, a current detection module, and a metering module respectively connected to the main control module. The power supply switching module includes: a standby battery, a charging power supply unit, and a switching unit. The metering module is used to measure the output of the charging pile during the test. The main control module is configured as follows: When no external power supply is connected, the switching unit is controlled to connect the standby battery to the power supply circuit and enter the standby state; After completing information interaction with the charging pile and starting charging, the charging power supply unit is controlled to connect to the power supply circuit, and the standby battery and the charging power supply unit are jointly powered. Once the charging current is determined to be stable based on the detection signal from the current detection module, the switching unit is controlled to disconnect the standby battery from the power supply circuit and switch to power supply solely by the charging power unit, while the charging power unit charges the standby battery. When a test stop signal is detected, the switching unit is controlled to reconnect the standby battery to the power supply circuit, and after a preset delay, the charging power supply unit is controlled to disconnect from the power supply circuit.

[0006] In some embodiments, the main control module is configured to: when a test stop signal is detected, control the switching unit to connect the standby battery to the power supply circuit, and then control the charging power supply unit to disconnect from the power supply circuit after a preset delay.

[0007] In some embodiments, the switching unit includes a high-voltage relay and a standby battery output relay. The high-voltage relay is connected in series between the charging power supply unit and the charging pile to control the connection and disconnection of the charging power supply unit. The standby battery output relay is connected in series between the standby battery and the power supply circuit of the multi-interface compatible high-precision portable DC charging pile testing device to control the connection and disconnection of the standby battery. The standby battery output relay is a normally closed relay, and the high-voltage relay is a normally open relay. The main control module is configured as follows: When a test stop signal is detected, a first control signal is output to de-energize the standby battery output relay coil, and the normally closed contact of the standby battery output relay is reset and energized, so that the standby battery is connected to the power supply circuit. After a preset delay, a second control signal is output to de-energize the high-voltage relay coil, causing the normally open contact of the high-voltage relay to open and the charging power unit to exit the power supply circuit.

[0008] In some embodiments, the test stop signal includes at least one of a stop command triggered by the human-machine interface and a stop charging message sent by the charging pile.

[0009] In some embodiments, the preset delay time is 0.5 seconds to 1.5 seconds.

[0010] In some embodiments, the current detection module includes a current transformer connected in series in the main charging circuit, the current transformer being used to convert the charging current into a sampling signal and transmit it to the main control module; The main control module is configured to continuously collect the sampling signal after charging starts, and determine that the charging current is stable when the fluctuation amplitude of the sampling signal is less than a preset threshold within N consecutive sampling periods, where N is an integer greater than or equal to 3.

[0011] In some embodiments, the metering module includes a built-in high-precision resistive load.

[0012] In some embodiments, the measurement accuracy of the metering module is ±(0.05% rdg + 0.05% fs), where rdg represents the reading error and fs represents the full-scale error.

[0013] In some embodiments, a multi-interface adaptation module is further included, which includes at least two different types of charging gun interfaces, an interface identification circuit, and a protocol switching unit; the interface identification circuit is used to identify the type of the currently inserted charging gun interface, and the protocol switching unit is used to switch the corresponding communication protocol stack according to the control instructions of the main control module.

[0014] In some embodiments, the main control module is further configured to: During the test, the standby battery power status is monitored in real time. When the standby battery power is detected to be lower than a preset threshold and the test device is in a state where it is powered solely by the charging power unit, the charging power unit is controlled to prioritize charging the standby battery until the standby battery power is restored to above the preset safety value. When the standby battery power is detected to be higher than a preset threshold and the testing device is in a standby state powered solely by the standby battery, the switching unit is controlled to connect the charging power unit to the power supply circuit to supplement the standby battery with charging.

[0015] In some embodiments, the testing apparatus further includes an interface adapter module, which includes at least two different types of charging gun interfaces for adapting to charging piles of different standards and models.

[0016] In one solution provided by the aforementioned high-precision portable DC charging pile testing device with multiple compatible interfaces, the device includes: a main control module, and a power supply switching module, a current detection module, and a metering module connected to the main control module. The power supply switching module includes: a standby battery, a charging power extraction unit, and a switching unit. The metering module is used to measure the output of the charging pile during the test. The main control module is configured as follows: when no external power supply is connected, the control switching unit connects the standby battery to the power supply circuit and enters a standby state; after completing information interaction with the charging pile and starting charging, the control charging power extraction unit connects to the power supply circuit, and the standby battery and the charging power extraction unit provide power together; when the charging current is stable according to the detection signal of the current detection module, the control switching unit disconnects the standby battery from the power supply circuit and switches to power supply solely by the charging power extraction unit, while the charging power extraction unit charges the standby battery; when a test stop signal is detected, the control switching unit reconnects the standby battery to the power supply circuit and disconnects the charging power extraction unit from the power supply circuit after a preset delay. In the aforementioned device, by setting up a power supply switching module and a main control module for coordinated control, after the test device is connected to the charging pile and charging is started, the charging power unit is automatically controlled to connect to the power supply circuit and disconnect the standby battery after judging the stability based on the current detection signal. This enables the charging power unit to supply power independently and charge the standby battery simultaneously, thereby enabling the test device to have an ultra-long battery life without the need for an external power source. This improves the battery life of the test device, which has a limited built-in battery capacity, thereby enhancing the efficiency and portability of outdoor field testing. While ensuring the battery life, the device also ensures that the power supply is not interrupted when the test stops by first connecting the standby battery and then delaying the disconnection of the charging power unit when the test stop signal is detected. This avoids data loss or device restart due to sudden power outages, thus ensuring the continuity and integrity of the testing process. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a circuit diagram of a high-precision portable DC charging pile testing device with multiple compatible interfaces in one embodiment of the present invention; Figure 2 This is a flowchart illustrating the first configuration step of the main control module in one embodiment of the present invention; Figure 3This is a flowchart illustrating the second configuration step of the main control module in one embodiment of the present invention; Figure 4 This is a flowchart illustrating the third configuration step of the main control module in one embodiment of the present invention. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] It should be understood that, when used in this specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or collections thereof. It should also be understood that, as used in this specification and the appended claims, the term "and / or" refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0021] Furthermore, in the description of this invention and the appended claims, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0022] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of the invention include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0023] It should be understood that the sequence number of each step in the following embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0024] To illustrate the technical solution of the present invention, specific embodiments are described below.

[0025] With the rapid development of the new energy vehicle industry, the popularity of DC charging piles is constantly increasing, and the demand for on-site metrology and testing is growing. At present, charging pile testers on the market usually adopt a solution of built-in small-capacity battery power supply to achieve portability, and an external load is required to complete the testing work.

[0026] In existing technologies, commercially available charging pile testers typically employ a built-in small-capacity battery for portability, requiring an external load to complete the testing. However, due to the limited capacity of the built-in battery, the tester can only support short periods of continuous operation outdoors. Once the battery is depleted, testing must be interrupted for charging or reliance on an external power source. External loads are bulky, have complex wiring, and must be carried separately from the tester. Furthermore, convenient AC power interfaces are often lacking in outdoor environments, forcing testers to carry additional outdoor power supplies and load equipment. This not only increases the number of devices carried and the amount of wiring work on-site but also frequently forces test interruptions due to insufficient battery power or load connection problems, severely reducing the continuity and ease of operation of on-site testing.

[0027] To address the aforementioned issues, this application provides a high-precision portable DC charging pile testing device with multiple interface compatibility. For example... Figure 1 As shown, the high-precision portable DC charging pile test device 100 with multiple interfaces includes: a main control module 11, and a power supply switching module 12, a current detection module 13, and a metering module 14, which are respectively connected to the main control module 11.

[0028] The power supply switching module 12 includes a standby battery 121, a charging power supply unit 122, and a switching unit 123. The switching unit 123 is used to selectively connect the standby battery 121 or the charging power supply unit 122 to the power supply circuit of the high-precision portable DC charging pile test device with multiple interfaces.

[0029] The current detection module 13 is connected in series in the main charging circuit to detect the charging current and transmit the detection signal to the main control module 11. The current detection module 13 (with a transformation ratio error of less than 0.05%) acquires the load current signal.

[0030] The metering module 14 is used to collect and measure the output voltage and current of the charging pile.

[0031] For example, during the charging test, the built-in high-precision resistive load 141 (10kW) of the metering module 14 is connected to the charging main circuit to simulate the load conditions of an electric vehicle. The high-precision resistive voltage divider network 142 (voltage divider ratio error <0.05%) collects the load voltage signal. The two signals are converted into digital quantities by a 24-bit high-precision ADC acquisition unit (not shown in the figure) and transmitted to the main control module 11. The main control module 11 calculates parameters such as instantaneous power, cumulative energy, and effective values ​​of voltage and current at a frequency of 10 times per second, and displays the data in real time on the human-machine interface. A metering report can be generated after the test is completed.

[0032] In another implementation, the metering module 14 uses a digital energy meter chip (such as the ADE9000), which integrates a multi-channel ADC, a digital integrator, and a power calculation engine. The main control module 11 reads the values ​​of the voltage, current, active power, reactive power, and energy registers inside the chip via the SPI interface and corrects them according to the calibration coefficient. Simultaneously, the main control module 11 monitors the temperature of the high-precision resistive load 141 in real time. When the temperature change exceeds a preset range, it calls a pre-calibrated temperature compensation curve to correct the metering results, eliminating the impact of temperature drift on accuracy and ensuring high-precision metering of ±(0.05% rdg + 0.05% fs) under different ambient temperatures.

[0033] like Figure 2 As shown, the configuration execution steps of the main control module 11 include: S10-S40.

[0034] S10. When no external power supply is connected, the control switching unit 123 connects the standby battery 121 to the power supply circuit, so that the test device enters the standby state.

[0035] For example, in an outdoor setting, the tester takes the test device 100 out of its carrying case, at which point the device is not connected to any external power source. The tester presses the start button (S1) on the device panel. After the main control module 11 detects the button trigger signal, it outputs a control signal through the IO port to energize the coil of the standby battery output relay (KA1). Its normally open contact closes, and the DC voltage (e.g., 12V) of the standby battery 121 is introduced into the power supply circuit of the test device 100 to power the main control module 11, the human-machine interface, and other standby circuits. The screen lights up, and the device enters standby mode, waiting to connect to the charging pile.

[0036] In another implementation, the test device 100 does not have a physical start button. Instead, it detects the device being picked up using an external vibration sensor. When the tester picks up the device from its storage location, the vibration sensor generates a trigger signal. The main control module 11 is then awakened and connects the standby battery 121 to the power supply circuit via an electronic switch (such as a MOSFET). The device automatically enters standby mode, and the human-machine interface displays the standby screen, prompting the tester to connect to a charging station.

[0037] S20. After completing information interaction with the charging pile and starting charging, control the charging power supply unit 122 to connect to the power supply circuit, so that the test device is powered by the standby battery 121 and the charging power supply unit 122.

[0038] like Figure 1 As shown, the charging and power supply unit 122 includes: a DC / DC power supply unit 1221, a battery charger 1222, and an AC power supply unit 1223.

[0039] For example, the tester inserts the charging gun of the test device 100 into the charging pile under test. The test device 100 and the charging pile complete a communication protocol handshake via the CAN bus (such as the GB / T 27930 protocol). After both parties confirm that the connection is normal, the tester starts charging on the charging pile. After the main control module 11 detects the charging start signal, it outputs a +12V voltage through the IO2 port to control the coil of the high-voltage relay KM1 to be energized. Its normally open contact closes, and the high-voltage DC power (such as 200V-750V) output by the charging pile is converted into ±12V operating voltage by the DC / DC power supply unit 1221 (model DDRH-240-12) and connected to the power supply circuit of the test device 100. At this time, the standby battery 121 remains connected, and the test device 100 is powered by the standby battery 121 and the DC / DC power supply unit 1221 to ensure stable power supply.

[0040] In another implementation, the testing device 100 interacts with the charging pile via a wireless communication module (such as Bluetooth or Wi-Fi). After the tester pairs the testing device 100 with a mobile app, the app communicates with the charging pile's cloud platform to obtain the charging pile's status. When the tester clicks "Start Test" on the app, the charging pile starts outputting power via a wireless command. After receiving the wireless signal, the main control module 11 controls the charging power supply unit 122 to connect to the power supply circuit via a solid-state relay (SSR). This implementation is suitable for scenarios where the charging pile does not have a physical plug-in start function, expanding the device's applicability.

[0041] S30. When the charging current is determined to be stable based on the detection signal of the current detection module 13, the control switching unit 123 disconnects the standby battery 121 from the power supply circuit, so that the test device is switched to be powered by the charging power unit 122 alone, and the charging power unit 122 charges the standby battery 121.

[0042] For example, after charging starts, the current transformer 131 (CT) connected in series in the main charging circuit collects the charging current in real time and transmits the sampling signal to the ADC port of the main control module 11. The main control module 11 continuously collects the sampling value with a period of 100ms. When the current value fluctuation within 5 consecutive sampling periods is less than a preset threshold (e.g., ±0.5A), the main control module 11 determines that the charging current has stabilized. Subsequently, the main control module 11 outputs a control signal through the IO1 port to de-energize the coil of the standby battery output relay KA1, and its normally closed contact is reset and opened, disconnecting the standby battery 121 from the power supply circuit. At this time, the test device 100 is completely powered by the DC / DC power supply unit 1221, and at the same time, one power output from the DC / DC power supply unit 1221 is used to charge the standby battery 121 with constant current and constant voltage through the battery charger 1222.

[0043] In another implementation, the current detection module 13 uses a Hall current sensor to collect the charging current, and its output is an analog voltage signal proportional to the charging current. The main control module 11 uses a digital filtering algorithm (such as moving average filtering) to smooth the collected signal and eliminate instantaneous spike interference. When the filtered current value is within ±1% of the rated current for 2 consecutive seconds, the main control module 11 determines that the current is stable. Subsequently, the main control module 11 controls the power MOSFET switch through an optocoupler isolation circuit to disconnect the standby battery 121 from the power supply circuit. At the same time, the charging power unit 122 performs maximum power point tracking (MPPT) charging for the standby battery 121 through an independent charging management chip (such as BQ24650) to improve charging efficiency.

[0044] S40. When a test stop signal is detected, the control switching unit 123 reconnects the standby battery 121 to the power supply circuit and controls the charging power supply unit 122 to disconnect from the power supply circuit after a preset delay.

[0045] For example, after completing the metrological test, the tester clicks the "Stop" button on the human-machine interface of the testing device 100. Upon detecting the stop command, the main control module 11 immediately outputs a control signal through the IO1 port to energize the coil of the standby battery output relay KA1, causing its normally closed contact to reset and close. The standby battery 121 is then reconnected to the power supply circuit within 50ms. Simultaneously, the main control module 11 starts a delay timer. After the delay ends, it outputs a control signal through the IO2 port to de-energize the coil of the high-voltage relay KM1, causing its normally open contact to open, and the charging power unit 122 to exit the power supply circuit. Throughout the entire switching process, the power supply to the testing device 100 remains uninterrupted, the screen remains lit, and the test data is completely retained.

[0046] In another implementation, the test stop signal originates from a stop charging message (CST) actively sent by the charging pile. Upon receiving this message via the CAN bus, the main control module 11 immediately triggers an interrupt handler. In the interrupt service function, the main control module 11 prioritizes the standby battery access operation, controlling the power management chip (PMIC) via the I2C interface to enable the output path of the standby battery 121. Simultaneously, a configurable delay register (default 0.5-1.5 seconds) is set. After the delay register counts down to zero, the enable pin of the charging power unit 122 is controlled via GPIO to cut off its output. This implementation allows for dynamic adjustment of the delay parameters based on the power-off response time of different charging piles, improving system compatibility.

[0047] In one solution provided by the aforementioned high-precision portable DC charging pile testing device with multiple compatible interfaces, the device includes: a main control module, and a power supply switching module, a current detection module, and a metering module connected to the main control module. The power supply switching module includes: a standby battery, a charging power extraction unit, and a switching unit. The metering module is used to measure the output of the charging pile during the test. The main control module is configured as follows: when no external power supply is connected, the control switching unit connects the standby battery to the power supply circuit and enters a standby state; after completing information interaction with the charging pile and starting charging, the control charging power extraction unit connects to the power supply circuit, and the standby battery and the charging power extraction unit provide power together; when the charging current is stable according to the detection signal of the current detection module, the control switching unit disconnects the standby battery from the power supply circuit and switches to power supply solely by the charging power extraction unit, while the charging power extraction unit charges the standby battery; when a test stop signal is detected, the control switching unit reconnects the standby battery to the power supply circuit and disconnects the charging power extraction unit from the power supply circuit after a preset delay. In the aforementioned device, by setting up a power supply switching module and a main control module for coordinated control, after the test device is connected to the charging pile and charging is started, the charging power unit is automatically controlled to connect to the power supply circuit and disconnect the standby battery after judging the stability based on the current detection signal. This enables the charging power unit to supply power independently and charge the standby battery simultaneously, thereby enabling the test device to have an ultra-long battery life without the need for an external power source. This improves the battery life of the test device, which has a limited built-in battery capacity, thereby enhancing the efficiency and portability of outdoor field testing. While ensuring the battery life, the device also ensures that the power supply is not interrupted when the test stops by first connecting the standby battery and then delaying the disconnection of the charging power unit when the test stop signal is detected. This avoids data loss or device restart due to sudden power outages, thus ensuring the continuity and integrity of the testing process.

[0048] In some embodiments, such as Figure 1 As shown, the switching unit 123 includes a high-voltage relay KM1 and a standby battery output relay KA1. The high-voltage relay KM1 is connected in series between the charging power supply unit 122 and the charging pile to control the connection and disconnection of the charging power supply unit 122. The standby battery output relay KA1 is connected in series between the standby battery 121 and the power supply circuit of the test device 100 to control the connection and disconnection of the standby battery 121. The standby battery output relay KA1 is a normally closed relay, and the high-voltage relay KM1 is a normally open relay.

[0049] The switching unit 123 also includes a loop relay S1. When the external power supply is not connected during outdoor testing, pressing the button (S1) will use the standby battery 121 to power the tester, wake up the main control MCU and the human-machine interface, and put the test device into standby mode.

[0050] like Figure 3 As shown, the main control module 11 is configured to execute steps S41 to S42.

[0051] S41. When a test stop signal is detected, the first control signal is output through the first control port to de-energize the coil of the standby battery output relay KA1, and the normally closed contact of the standby battery output relay KA1 is reset and energized, so that the standby battery 121 is connected to the power supply circuit.

[0052] S42. After a preset delay, a second control signal is output through the second control port to de-energize the coil of the high-voltage relay KM1, and the normally open contact of the high-voltage relay KM1 is opened, causing the charging power unit 122 to exit the power supply circuit.

[0053] For example, the switching unit 123 adopts a normally closed standby battery output relay KA1 and a normally open high-voltage relay KM1 to form a dual relay structure. When the standby battery output relay KA1 is not energized, its normally closed contact remains closed, so that the standby battery 121 and the power supply circuit are in a normally connected state. When the high-voltage relay KM1 is not energized, its normally open contact remains open, so that the charging power unit 122 and the charging pile are in an isolated state. When the test device 100 is in standby mode, the normally closed contact of the standby battery output relay KA1 is in the energized state, and the standby battery 121 supplies power to the test device 100. When the test device 100 enters the charging test state, the main control module 11 outputs a first control signal through the first control port to energize the coil of the standby battery output relay KA1, and its normally closed contact opens, disconnecting the standby battery 121 from the power supply circuit. At the same time, the main control module 11 outputs a second control signal through the second control port to energize the coil of the high voltage relay KM1, and its normally open contact closes, connecting the charging power unit 122 to the power supply circuit. When the main control module 11 detects a test stop signal, it stops outputting the first control signal through the first control port. The coil of the standby battery output relay KA1 is de-energized, and its normally closed contact resets and engages. The standby battery 121 is reconnected to the power supply circuit within 50 milliseconds. After a preset delay, the main control module 11 stops outputting the second control signal through the second control port. The coil of the high-voltage relay KM1 is de-energized, and its normally open contact opens, causing the charging power supply unit 122 to exit the power supply circuit. This embodiment, through the cooperation of normally closed and normally open relays, automatically resets and connects the standby battery 121 when the coil of the standby battery output relay KA1 is de-energized, and automatically disconnects the charging power supply unit 122 when the coil of the high-voltage relay KM1 is de-energized. This achieves hardware-level reliability assurance for power supply switching and avoids the risk of power supply switching failure due to software abnormalities or signal transmission failures in the main control module 11.

[0054] In some embodiments, the test stop signal includes at least one of a stop command triggered by the human-machine interface and a stop charging message sent by the charging pile.

[0055] In this embodiment, the main control module 11 is configured to simultaneously respond to two test stop signals: a stop command from the human-machine interface and a stop charging message from the charging pile. When the tester clicks the stop button on the human-machine interface of the test device 100, the human-machine interface generates a stop command and transmits it to the main control module 11. The main control module 11 recognizes the stop command as a test stop signal and performs a power supply switching operation. When the charging pile actively stops outputting power during the test due to full charge, malfunction, or user operation, the charging pile sends a stop charging message to the test device 100 via the CAN bus. The main control module 11 receives the stop charging message via the CAN bus, recognizes it as a test stop signal, and performs a power supply switching operation. Through this dual signal source recognition mechanism, regardless of whether the test stop is caused by the tester's active operation or by the charging pile, the main control module 11 can respond promptly and execute the same power supply switching logic. This ensures that the test device 100 can achieve timely access to the standby battery 121 and seamless power supply switching in any stop scenario, solving the problem of power outage caused by the inability to recognize the stop signal when the charging pile actively stops in existing test instruments.

[0056] In some embodiments, the preset delay time is 0.5 seconds to 1.5 seconds.

[0057] For example, the preset delay time is set to a fixed value between 0.5 seconds and 1.5 seconds. This time window ensures that the standby battery output relay KA1 completes the mechanical reset action and establishes a stable power supply for the standby battery 121 (approximately 50 milliseconds in actual measurement), while also ensuring that the main control module 11 of the test device 100 has sufficient time to save the current test data and complete the status recording before the charging power unit 122 is disconnected. When the preset delay time is set to 1 second, the main control module 11 immediately connects to the standby battery 121 after detecting the test stop signal. The standby battery 121 completes the connection and establishes a stable power supply within 50 milliseconds. The main control module 11 uses the remaining 950 milliseconds to write the test data such as voltage, current, and cumulative energy collected by the metering module 14 into the non-volatile memory, and waits for the delay timer to end before disconnecting the charging power unit 122. The setting of this delay parameter enables the test device 100 to achieve both seamless power connection and complete preservation of test data during power switching. At the same time, the 1-second delay will not cause testers to feel a significant response delay, thus balancing reliability and user experience.

[0058] In some embodiments, the current detection module 13 includes a current transformer 131 connected in series in the main charging circuit. The current transformer 131 is used to convert the charging current into a sampling signal and transmit it to the main control module 11. The main control module 11 is configured to execute step S31.

[0059] S31. After charging starts, continuously collect sampling signals. When the fluctuation amplitude of the sampling signal within N consecutive sampling periods is less than a preset threshold, it is determined that the charging current is stable, where N is an integer greater than or equal to 3.

[0060] For example, the primary side of the current transformer 131 is connected in series in the main charging circuit. When the charging current flows through the primary side of the current transformer 131, the secondary side of the current transformer 131 induces a sampling signal proportional to the charging current and transmits the sampling signal to the analog-to-digital conversion port of the main control module 11. After charging starts, the main control module 11 continuously acquires the sampling signal at a fixed sampling period and converts it into a digital quantity. At the moment of charging start, the charging current rises from zero and may experience momentary overshoot or oscillation. The main control module 11 calculates the current change between adjacent sampling periods in N consecutive sampling periods. When the current change in each sampling period in N consecutive sampling periods is less than a preset threshold (e.g., ±1% of the rated current), the main control module 11 determines that the charging current has entered a stable state. When N is 5, the main control module 11 detects that the current fluctuation amplitude is less than the preset threshold in 5 consecutive sampling periods (corresponding to 500 milliseconds), thus confirming that the charging current has stabilized, and then performs the disconnection operation of the standby battery 121. This embodiment effectively avoids misjudgments caused by current spikes or brief fluctuations at the moment of charging start-up through a continuous multi-cycle judgment mechanism, ensuring that the standby battery 121 is only disconnected after the charging current is truly stable, thereby improving the reliability of power supply switching and preventing power supply fluctuations caused by the standby battery 121 being accidentally disconnected when the charging state is unstable.

[0061] In some embodiments, the metering module 14 includes a built-in high-precision resistive load 141.

[0062] For example, the metering module 14 incorporates a high-precision resistive load 141, which is composed of multiple high-stability power resistors connected in parallel. The rate of change of its total resistance within the rated operating temperature range is controlled within ±0.1%. The input terminal of the high-precision resistive load 141 is connected to the output terminal of the charging pile via the switching unit 123. When the testing device 100 enters the charging test state, the high-precision resistive load 141 is connected to the main charging circuit to replace the electric vehicle as the load of the charging pile. When the DC current output by the charging pile flows through the high-precision resistive load 141, a voltage drop proportional to the current value is generated across the high-precision resistive load 141. The metering module 14 calculates the actual output voltage and actual output current of the charging pile by collecting the voltage value across the high-precision resistive load 141 and the current value flowing through the high-precision resistive load 141. Since the resistance value of the high-precision resistive load 141 is highly stable and known, the output power of the charging pile can be directly obtained by multiplying the voltage and current without relying on external load equipment. When the test device 100 is used in the outdoor field, there is no need to carry an external load box, which simplifies the preparation work for on-site testing and greatly improves the portability of the test device.

[0063] In some embodiments, the measurement accuracy of the measurement module 14 is ±(0.05% rdg + 0.05% fs), where rdg represents the reading error and fs represents the full-scale error.

[0064] For example, the measurement accuracy of the measurement module 14 is defined as ±(0.05% rdg + 0.05% fs), where the reading error rdg is the product of the relative error between the measured value and the actual value and the current reading, and the full-scale error fs is the product of the absolute error between the measured value and the actual value and the measurement range. When the metering module 14 measures the charging pile output voltage as 750V, with the full scale calculated as 1000V, the reading error is 0.05% of 750V, i.e., 0.375V; the full scale error is 0.05% of 1000V, i.e., 0.5V; the total error does not exceed ±0.875V, and the relative error is better than 0.12%. When the metering module 14 measures the charging pile output current as 250A, with the full scale calculated as 300A, the reading error is 0.05% of 250A, i.e., 0.125A; the full scale error is 0.05% of 300A, i.e., 0.15A; the total error does not exceed ±0.275A, and the relative error is better than 0.11%. This accuracy meets the highest accuracy requirements for on-site verification devices in JJG 1148-2022 "Verification Procedure for AC Charging Piles of Electric Vehicles" and JJG 1199-2023 "Verification Procedure for Off-board Chargers of Electric Vehicles", enabling the test device 100 to be qualified to conduct legal metrological verification of charging piles and to be used as a metrological calibration instrument for factory testing and on-site periodic verification of charging piles.

[0065] In some embodiments, the high-precision portable DC charging pile testing device 100 with multiple interfaces also includes a multi-interface adaptation module 15. The multi-interface adaptation module 15 includes at least two different types of charging gun interfaces, an interface identification circuit, and a protocol switching unit. The interface identification circuit is used to identify the type of the currently inserted charging gun interface, and the protocol switching unit is used to switch the corresponding communication protocol stack according to the control instructions of the main control module 11.

[0066] For example, the multi-interface adapter module 15 is configured with at least two different types of charging gun interfaces, including the Chinese standard DC charging gun interface, the European standard DC charging gun interface, and the American standard DC charging gun interface. Each charging gun interface corresponds to a different mechanical structure and electrical pin definition. The interface identification circuit is connected to the identification pin of each charging gun interface. When the tester inserts the charging gun into one of the charging gun interfaces, the interface identification circuit detects that the identification pin corresponding to the charging gun interface is triggered, generates the corresponding interface type code, and transmits it to the main control module 11. The main control module 11 identifies the currently used charging gun interface type according to the received interface type code and calls the pre-stored communication protocol stack that matches the interface type. The communication protocol stack includes one of the following protocols: GB / T 27930, DIN 70121, or ISO 15118. The main control module 11 loads the selected communication protocol stack into the protocol register of the communication controller through the protocol switching unit, so that the test device 100 and the charging pile can interact with each other according to the correct communication protocol. This embodiment enables a single testing device 100 to be compatible with various standards and models of charging piles, avoiding the inconvenience of testing personnel carrying multiple dedicated testing instruments on site, and further improving the portability and versatility of the testing device 100.

[0067] In some embodiments, such as Figure 4 The main control module 11 is also configured to execute steps S60 to S70.

[0068] S60. During the test, the power status of the standby battery 121 is monitored in real time. When the power of the standby battery 121 is detected to be lower than the preset threshold and the test device 100 is in a state where it is powered solely by the charging power unit 122, the charging power unit 122 is controlled to charge the standby battery 121 first until the power of the standby battery 121 is restored to above the preset safety value.

[0069] S70. When the power level of the standby battery 121 is detected to be higher than the preset threshold and the test device 100 is in a standby state powered solely by the standby battery 121, the control switching unit 123 connects the charging power unit 122 to the power supply circuit to supplement the charging of the standby battery 121.

[0070] For example, the main control module 11 reads the remaining power percentage of the standby battery 121 in real time through the battery management chip. When the main control module 11 detects that the remaining power of the standby battery 121 is lower than a preset low power threshold (e.g., 20%) and the test device 100 is currently in a charging test state powered solely by the charging power unit 122, the main control module 11 sends a charging enable command to the battery charger 1222 inside the charging power unit 122 and configures the charging current as a priority level, so that most of the electrical energy output by the charging power unit 122 is used to charge the standby battery 121 until the remaining power of the standby battery 121 is restored to a preset safety value (e.g., 80%) or higher, the main control module 11 then restores the charging current to the normal level. When the main control module 11 detects that the remaining power of the standby battery 121 is higher than a preset high power threshold (e.g., 95%) and the test device 100 is currently in a standby state powered solely by the standby battery 121, the main control module 11 controls the switching unit 123 to connect the charging power unit 122 to the power supply circuit. The charging power unit 122 draws power from the charging pile or external power source to perform float charging supplementary charging for the standby battery 121, keeping the standby battery 121 in a near-fully charged state. This embodiment, through intelligent battery charging management, ensures that the standby battery 121 maintains sufficient power reserves under any operating conditions, providing continuous protection for the standby battery life of the test device 100, enabling the test device 100 to maintain a standby usable state for a long time in outdoor environments without external power sources.

[0071] In some embodiments, the testing apparatus further includes an interface adaptation module, which includes at least two different types of charging gun interfaces for adapting to charging piles of different standards and models. This allows the testing apparatus to test charging piles with different interfaces, thereby improving its applicability.

[0072] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0073] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0074] In the embodiments provided in this application, it should be understood that the disclosed apparatus / device and method can be implemented in other ways. For example, the apparatus / device embodiments described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0075] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0076] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A high-precision portable DC charging pile testing device with multiple interface compatibility, characterized in that, include: The main control module, and a power supply switching module, a current detection module and a metering module respectively connected to the main control module, the power supply switching module includes: a standby battery, a charging power supply unit and a switching unit, and the metering module is used to measure the output of the charging pile during the test; The main control module is configured as follows: When no external power supply is connected, the switching unit is controlled to connect the standby battery to the power supply circuit and enter the standby state; After completing information interaction with the charging pile and starting charging, the charging power supply unit is controlled to connect to the power supply circuit, and the standby battery and the charging power supply unit are jointly powered. Once the charging current is determined to be stable based on the detection signal from the current detection module, the switching unit is controlled to disconnect the standby battery from the power supply circuit and switch to power supply solely by the charging power unit, while the charging power unit charges the standby battery. When a test stop signal is detected, the switching unit is controlled to reconnect the standby battery to the power supply circuit, and after a preset delay, the charging power supply unit is controlled to disconnect from the power supply circuit.

2. The high-precision portable DC charging pile testing device with multiple compatible interfaces according to claim 1, characterized in that, The switching unit includes a high-voltage relay and a standby battery output relay. The high-voltage relay is connected in series between the charging power supply unit and the charging pile to control the connection and disconnection of the charging power supply unit. The standby battery output relay is connected in series between the standby battery and the power supply circuit of the multi-interface compatible high-precision portable DC charging pile test device to control the connection and disconnection of the standby battery. The standby battery output relay is a normally closed relay, and the high-voltage relay is a normally open relay. The main control module is configured as follows: When a test stop signal is detected, a first control signal is output to de-energize the standby battery output relay coil, and the normally closed contact of the standby battery output relay is reset and energized, so that the standby battery is connected to the power supply circuit. After a preset delay, a second control signal is output to de-energize the high-voltage relay coil, causing the normally open contact of the high-voltage relay to open and the charging power unit to exit the power supply circuit.

3. The high-precision portable DC charging pile testing device with multiple compatible interfaces according to claim 1, characterized in that, The test stop signal includes at least one of the following: a stop command triggered by the human-machine interface and a stop charging message sent by the charging pile.

4. The high-precision portable DC charging pile testing device with multiple compatible interfaces according to claim 1, characterized in that, The preset delay time is 0.5 seconds to 1.5 seconds.

5. The high-precision portable DC charging pile testing device with multiple compatible interfaces according to claim 1, characterized in that, The current detection module includes a current transformer connected in series in the main charging circuit. The current transformer is used to convert the charging current into a sampling signal and transmit it to the main control module. The main control module is configured to continuously collect the sampling signal after charging starts, and determine that the charging current is stable when the fluctuation amplitude of the sampling signal is less than a preset threshold within N consecutive sampling periods, where N is an integer greater than or equal to 3.

6. The high-precision portable DC charging pile testing device with multiple compatible interfaces according to claim 1, characterized in that, The metering module includes a built-in high-precision resistive load.

7. The high-precision portable DC charging pile testing device with multiple compatible interfaces according to claim 6, characterized in that, The measurement accuracy of the metering module is ±(0.05% rdg + 0.05% fs), where rdg represents the reading error and fs represents the full-scale error.

8. The high-precision portable DC charging pile testing device with multiple compatible interfaces according to claim 1, characterized in that, It also includes a multi-interface adaptation module, which includes at least two different types of charging gun interfaces, an interface identification circuit, and a protocol switching unit; the interface identification circuit is used to identify the type of the currently inserted charging gun interface, and the protocol switching unit is used to switch the corresponding communication protocol stack according to the control instructions of the main control module.

9. The high-precision portable DC charging pile testing device with multiple compatible interfaces according to claim 1, characterized in that, The main control module is also configured to: During the test, the standby battery power status is monitored in real time. When the standby battery power is detected to be lower than a preset threshold and the test device is in a state where it is powered solely by the charging power unit, the charging power unit is controlled to prioritize charging the standby battery until the standby battery power is restored to above the preset safety value. When the standby battery power is detected to be higher than a preset threshold and the testing device is in a standby state powered solely by the standby battery, the switching unit is controlled to connect the charging power unit to the power supply circuit to supplement the standby battery with charging.

10. The high-precision portable DC charging pile testing device with multiple compatible interfaces according to claim 1, characterized in that, Also includes: An interface adapter module is provided, which includes at least two different types of charging gun interfaces for adapting to charging piles of different standards and models.

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