Calibration test system for three-phase TMR current sensor

Abstract

The invention relates to the field of current sensor testing, in particular to a calibration test system for a three-phase TMR current sensor, which is provided with a calibration test mode switching device and organically integrates a calibration mode and a test mode into the same equipment. The current sensors with different compatibility can be calibrated and tested, the accuracy of the calibration and test results of the current sensors is ensured, the research and development efficiency is improved, and the equipment investment is reduced.

Description

Technical Field

[0001] The present invention relates to the field of current sensor testing, and in particular to a calibration test system for a three-phase TMR current sensor. Background Art

[0002] New energy vehicle motor controllers contain a current sensor for detecting current. By detecting the magnitude and direction of the current, it transmits a signal to the controller for monitoring and controlling the motor current. Therefore, the current detection accuracy and reliability of this current sensor directly determine the control efficiency of the electric drive controller, as well as the stability and safety of the vehicle. In actual R&D and production processes, current sensors are typically calibrated and tested separately using two separate devices. However, this approach to current sensor calibration and testing presents numerous issues: ① The operation process is cumbersome and complicated During the development and production of current sensors, the process of calibrating and testing them sequentially between two devices is cumbersome and complex. For example, after the calibration phase is completed and before switching to the testing phase, the calibration equipment must be shut down and powered off. All cables connected to the current sensor, such as the power cord, signal cable, and ground cable, must be carefully removed and labeled to avoid confusion during subsequent connections. The current sensor must then be removed from its designated location on the calibration equipment. This process may involve loosening fasteners and unplugging connectors, and caution is required to prevent physical damage to the sensor. The calibrated current sensor is then transferred to the test equipment and the installation process begins again. During this process, the sensor must be precisely secured in place according to the test equipment's interface type and installation requirements. The previously removed cables must be connected one by one, ensuring that each cable is connected to the correct interface. The connections must also be checked for looseness or poor contact. This operation method significantly increases the number of connection, disassembly, and installation steps, requiring operators to invest more energy and time. It also increases the risk of inaccurate calibration and test results due to operational errors, making the entire calibration and testing process cumbersome and complicated, seriously affecting work efficiency and quality.

[0003] ② Device compatibility issues During the calibration and testing process of current sensors, the calibration and testing equipment involved may originate from different manufacturers, potentially leading to compatibility issues in various areas, including interface type, communication protocol, and signal format. For example, when one device outputs an analog signal while the connected device only receives digital signals, an additional signal conversion device must be introduced. This not only increases costs but can also introduce errors during the signal conversion process, leading to deviations in the calibration and testing of the current sensor, ultimately requiring rework and significantly reducing the efficiency and quality of R&D and production activities.

[0004] ③ Device consistency issues When calibrating and testing current sensors, the calibration equipment and test equipment used may differ in measurement precision and accuracy to a certain extent. Even if both types of equipment are deemed accurate and reliable within their respective specifications, slight deviations may still exist between them. For example, when two different current source devices output the same set current, the actual output current may differ due to factors such as manufacturing tolerances and calibration status. This difference can lead to inconsistent measurement results for the same sensor characteristic when testing current sensors. For example, when two different current source devices are set to output the same current value, the actual output current value may differ due to factors such as manufacturing tolerances and calibration status. This inconsistency can lead to different measurement results for the same sensor characteristic when testing current sensors. For example, when testing sensor sensitivity, the sensitivity value measured using calibration equipment may differ from the result obtained using test equipment. This makes it difficult to determine the true performance parameters of the current sensor and to quickly determine whether the problem lies with the current sensor itself or the device used. Therefore, it takes extra time to inspect and test the two devices and the current sensor separately, which seriously disrupts the continuity of R&D and production work and causes a significant decline in production efficiency.

[0005] Therefore, when calibrating and testing a current sensor, how to ensure the accuracy of the current sensor calibration and test results while improving the R&D and production efficiency as much as possible has always been a problem that needs to be solved urgently by those skilled in the art. Summary of the Invention

[0006] The purpose of the present invention is to address the corresponding deficiencies in the existing technology and provide a calibration and testing system for a three-phase TMR current sensor. The system organically integrates the calibration and testing modes into the same device, and can calibrate and test current sensors of different compatibilities. While ensuring the accuracy of the current sensor calibration and test results, it improves the efficiency of R&D and production and reduces equipment investment.

[0007] The purpose of the present invention is to adopt the following scheme to achieve: A calibration and testing system for a three-phase TMR current sensor, comprising: The test host is used to control the calibration test system to realize the calibration and test functions of the current sensor to be tested; A calibration test mode switching device, used for switching the calibration and test modes of the calibration test system for the current sensor to be tested; Current chip calibration equipment, used to calibrate the parameters of the current chip of the current sensor to be tested; A current generating and reversing device, used to generate primary currents of different directions required in the process of testing the current sensor to be tested; A data acquisition device is used to collect the output voltage signal of the current sensor to be tested and transmit the collected voltage signal to the test host; A first power supply is used to supply power to the current generating and switching device, the calibration test mode switching device and the current sensor to be measured; The current chip calibration device and the data acquisition device are both directly connected to the test host, the output end of the test host is directly connected to the calibration test mode switching device, and the current sensor to be tested is respectively connected to the current chip calibration device and the data acquisition device through the calibration test mode switching device, the test host is directly connected to the current generating and reversing device, the current generating and reversing device is connected to the calibration test mode switching device, and the current generating and reversing device and the calibration test mode switching device are both connected to the first power supply.

[0008] Preferably, the current generating and commutating device includes a second power supply, an electronic load, and a current commutating device, wherein the second power supply is used to generate the primary current required for testing the current sensor; The electronic load is used to protect the circuit and simulate the actual load during the use of the current sensor to be measured; The current reversing device is used to change the direction of the primary current; The second power supply is connected to the current reversing device through an electronic load, and the current output end of the current reversing device is connected to the copper bus of the calibration test mode switching device.

[0009] Preferably, the current chip calibration device includes a data collector and a burner, and the data acquisition port of the data collector is directly connected to the Vout port of the current sensor current chip to be tested, so as to collect the output voltage of the current sensor current chip to be tested during the test process for subsequent data analysis; The Vout port of the current sensor current chip to be measured is directly connected to the input port of the writer, so as to write data to the current sensor current chip to be measured during the calibration process.

[0010] Preferably, the data acquisition device has multi-channel acquisition, and the number of acquisition channels is ≥4, the acquisition accuracy is ≥0.1%, and the sampling rate is ≥1ksps.

[0011] Preferably, the calibration test mode switching device includes a test board, a dip switch PCB, and a copper busbar. The test board is fixedly mounted on the base, and a copper busbar mounting plate is fixedly mounted above the test board through a side plate and a support column. The dip switch PCB is arranged on the side of the side plate away from the test board. The dip switch PCB is electrically connected to the test board, and the copper busbar is fixed on the copper busbar mounting plate for installing the current sensor 15 to be measured.

[0012] Preferably, a plurality of first positioning posts are provided on the top of the copper busbar mounting plate, a product positioning plate is provided on the top of the copper busbar, a plurality of second positioning posts are provided on the bottom of the product positioning plate, and the first positioning posts are detachably connected to the corresponding second positioning posts; It also includes a plurality of product fixing blocks for limiting the current sensor to be measured, and both ends of the product fixing blocks are fixedly connected to the bottom surface of the product positioning plate.

[0013] Preferably, the copper bar includes an input copper bar, an output copper bar, and a bent copper bar group. One end of the bent copper bar group is connected to the input copper bar through a copper bar assembly, and the other end of the bent copper bar group is connected to the output copper bar through a copper bar assembly. A current sensor to be measured is mounted on the copper bar assembly.

[0014] Preferably, the current sensor to be tested, the current chip calibration device, the data acquisition device, and the test host are all electrically connected to the test board.

[0015] Preferably, a method for calibrating a test system comprises the following steps: 1) A judgment module is set in the calibration test system software set in the test host, and a zero point parameter threshold is set in the judgment module to determine whether the current sensor meets production requirements during the preliminary test of the current sensor to be tested; 2) Install the current sensor to be tested on the calibration test mode switching device. The test host switches the calibration test mode switching device to the test mode by adjusting the position of the dip switch on the dip switch PCB, and controls the current generation and reversing device to generate the primary current of different magnitudes and directions required for the test. 3) using a data collector to collect the zero-point parameter of the current sensor to be measured, and comparing the obtained zero-point parameter with the zero-point parameter threshold; 4) According to the judgment result of step 3), change the position of the DIP switch to switch the state of the calibration test mode switching device to the calibration mode, and write the zero point parameter into the current chip; 5) Parameter thresholds are also provided, including an accuracy threshold, a linearity threshold, a zero point threshold, and a gain parameter threshold, which serve as a basis for determining whether the calibrated current sensor meets the accuracy requirements; 6) The test host switches the state of the calibration test mode switching device to the test mode by adjusting the position of the dip switch on the dip switch PCB, and controls the current generation and reversing device to generate the primary current of different magnitudes and directions required for the test; 7) Using a data acquisition device to test the current sensor to be tested, collecting output voltage and resistance data of the current sensor to be tested under different primary currents, and transmitting the data to a test host for analysis and calculation to obtain test data of the current sensor to be tested, wherein the test data includes accuracy, linearity, zero point parameters, and gain parameters; 8) Compare the test data of the current sensor to be tested with the standard threshold values of various parameters to determine whether the calibrated current sensor to be tested meets the requirements.

[0016] Preferably, in step 8), the test data of the current sensor to be tested is compared with the standard threshold values of various parameters to determine whether the calibrated current sensor to be tested meets the requirements, and the specific manner of presenting the status of the current sensor to be tested on the display is as follows: 8-1) If it meets the requirements, the display will show that the current sensor to be tested is normal; 8-2) If it does not meet the requirements, the display will show that the current sensor to be tested is abnormal, and the above steps 3) to 7) will be repeated.

[0017] The present invention has the following beneficial effects: A calibration and testing system for a three-phase TMR current sensor, comprising: The test host is used to control the calibration test system to realize the calibration and test functions of the current sensor to be tested; A calibration test mode switching device, used for switching the calibration and test modes of the calibration test system for the current sensor to be tested; Current chip calibration equipment, used to calibrate the parameters of the current chip of the current sensor to be tested; A current generating and reversing device, used to generate primary currents of different directions required in the process of testing the current sensor to be tested; A data acquisition device is used to collect the output voltage signal of the current sensor to be tested and transmit the collected voltage signal to the test host; The current chip calibration device and the data acquisition device are both directly connected to the test host, the output end of the test host is directly connected to the calibration test mode switching device, and the current sensor to be tested is respectively connected to the current chip calibration device and the data acquisition device through the calibration test mode switching device, the test host is directly connected to the current generating and reversing device, the current generating and reversing device is connected to the calibration test mode switching device, and the current generating and reversing device and the calibration test mode switching device are both connected to the first power supply.

[0018] The present invention provides a calibration and test mode switching device. During the calibration and testing process of a three-phase TMR current sensor, an operator only needs to operate a test host, which sends a switching command to realize convenient switching between the calibration mode and the test mode. This significantly improves production efficiency, avoids errors caused by equipment precision differences, and greatly improves the accuracy of calibration and testing.

[0019] Preferably, the current generating and commutating device includes a second power supply, an electronic load, and a current commutating device, wherein the second power supply is used to generate the primary current required for testing the current sensor; The electronic load is used to protect the circuit and simulate the actual load during the use of the current sensor to be measured; The current reversing device is used to change the direction of the primary current; The second power supply is connected to the current reversing device through an electronic load, and the current output end of the current reversing device is connected to the copper bus of the calibration test mode switching device.

[0020] The present invention calibrates and tests the three-phase TMR current sensor by setting an electronic load to simulate the load in actual use of the three-phase TMR current sensor. Through this simulation, the performance of the three-phase TMR current sensor in actual working scenarios can be more realistically measured, ensuring that the sensor can accurately measure current even when facing complex and changeable loads, thereby effectively improving the accuracy of the current sensor calibration and test results.

[0021] Preferably, the data acquisition device has multi-channel acquisition, and the number of acquisition channels is ≥4, the acquisition accuracy is ≥0.1%, and the sampling rate is ≥1ksps.

[0022] The present invention adopts a multi-channel data acquisition device to enable the system to calibrate and test multiple three-phase TMR current sensors at the same time, thereby greatly improving production efficiency.

[0023] Preferably, the copper bar includes an input copper bar, an output copper bar, and a bent copper bar group. One end of the bent copper bar group is connected to the input copper bar through a copper bar assembly, and the other end of the bent copper bar group is connected to the output copper bar through a copper bar assembly. A current sensor to be measured is mounted on the copper bar assembly.

[0024] The present invention calibrates the current sensor by simulating actual usage conditions by setting the same copper bus and current input method as in actual application scenarios, thereby effectively improving the accuracy of the current sensor.

[0025] Preferably, a method for calibrating a test system comprises the following steps: 1) A judgment module is set in the calibration test system software set in the test host, and a zero point parameter threshold is set in the judgment module to determine whether the current sensor meets production requirements during the preliminary test of the current sensor to be tested; 2) Install the current sensor to be tested on the calibration test mode switching device. The test host switches the calibration test mode switching device to the test mode by adjusting the position of the dip switch on the dip switch PCB, and controls the current generation and reversing device to generate the primary current of different magnitudes and directions required for the test. 3) using a data collector to collect the zero-point parameter of the current sensor to be measured, and comparing the obtained zero-point parameter with the zero-point parameter threshold; 4) According to the judgment result of step 3), change the position of the DIP switch to switch the state of the calibration test mode switching device to the calibration mode, and write the zero point parameter into the current chip; 5) Parameter thresholds are also provided, including an accuracy threshold, a linearity threshold, a zero point threshold, and a gain parameter threshold, which serve as a basis for determining whether the calibrated current sensor meets the accuracy requirements; 6) The test host switches the state of the calibration test mode switching device to the test mode by adjusting the position of the dip switch on the dip switch PCB, and controls the current generation and reversing device to generate the primary current of different magnitudes and directions required for the test; 7) Using a data acquisition device to test the current sensor to be tested, collecting output voltage and resistance data of the current sensor to be tested under different primary currents, and transmitting the data to a test host for analysis and calculation to obtain test data of the current sensor to be tested, wherein the test data includes accuracy, linearity, zero point parameters, and gain parameters; 8) Compare the test data of the current sensor to be tested with the standard threshold values of various parameters to determine whether the calibrated current sensor to be tested meets the requirements.

[0026] Preferably, in step 8), the test data of the current sensor to be tested is compared with the standard threshold values of various parameters to determine whether the calibrated current sensor to be tested meets the requirements, and the specific manner of presenting the status of the current sensor to be tested on the display is as follows: 8-1) If it meets the requirements, the display will show that the current sensor to be tested is normal; 8-2) If it does not meet the requirements, the display will show that the current sensor to be tested is abnormal, and the above steps 3) to 7) will be repeated.

[0027] The present invention sets parameter thresholds, compares the parameters of the calibrated current sensor to be measured with the corresponding parameter thresholds, and performs calibration tests multiple times on the current sensor to be measured that initially displays an abnormality, thereby effectively ensuring that the accuracy of the current sensor to be measured meets the requirements after calibration and that the test data is accurate and reliable.

[0028] The advantages of the present invention are as follows: ① This invention integrates the calibration and testing functions of a three-phase TMR current sensor by providing a calibration and test mode switching device for switching between calibration and test modes. In actual operation, the three-phase TMR current sensor can be easily and efficiently switched between calibration and test modes simply by sending a specific switching command from the test host. This greatly simplifies the operation process, improves production efficiency, and reduces equipment investment.

[0029] Compared with the traditional three-phase TMR current sensor calibration and testing method, the present invention effectively avoids the complex and tedious line change process and fundamentally reduces the calibration and testing error risk introduced by equipment consistency differences and manual switching mode installation. It not only effectively improves production efficiency, but also effectively ensures that the accuracy of the three-phase TMR current sensor after calibration meets the requirements and the test data obtained is highly accurate and reliable.

[0030] ② The present invention increases the controllability of the primary current during the calibration and testing of the three-phase TMR current sensor through the current generation and commutation device, making it easier to cover a wider current range during the calibration and testing process, thereby meeting the calibration and testing requirements of different types of three-phase TMR current sensors for different current ranges.

[0031] At the same time, the present invention calibrates and tests the three-phase TMR current sensor by setting an electronic load to simulate the load in actual use of the three-phase TMR current sensor. Through this simulation, the performance of the three-phase TMR current sensor in an actual working scenario can be measured more realistically, ensuring that it can accurately measure current even when facing complex and changeable loads, effectively improving the accuracy of the current sensor calibration and test results.

[0032] ③ The present invention adopts a multi-channel data acquisition device, so that the system can calibrate and test multiple three-phase TMR current sensors simultaneously, greatly improving production efficiency. Glossary

[0033] PCB: Printed Circuit Board, also often called printed circuit board, printed circuit board. PCB is an important electronic component. It is the support body of electronic components and the carrier of electrical connection of electronic components. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is a schematic diagram of a calibration test system of the present invention; Figure 2 This is a functional block diagram of the calibration test mode switching device of the present invention; Figure 3 This is a simplified structural diagram of the calibration test mode switching device of the present invention; Figure 4 This is a functional block diagram of the current generating and commutating device of the present invention; Figure 5 This is a schematic diagram of the structure of the copper busbar of the calibration test mode switching device. DETAILED DESCRIPTION

[0035] like Figures 1 to 5 As shown, a calibration and testing system for a three-phase TMR current sensor includes: The test host is used to control the calibration test system to realize the calibration and test functions of the current sensor to be tested; A calibration test mode switching device, used for switching the calibration and test modes of the calibration test system for the current sensor to be tested; Current chip calibration equipment, used to calibrate the parameters of the current chip of the current sensor to be tested; A current generating and reversing device, used to generate primary currents of different directions required in the process of testing the current sensor to be tested; A data acquisition device is used to collect the output voltage signal of the current sensor to be tested and transmit the collected voltage signal to the test host; The first power supply is used to power the current generating and reversing device, the calibration test mode switching device and the current sensor to be measured; specifically, the above-mentioned first power supply is connected to the current reversing device to provide power for the current reversing device, and the maximum output voltage of the first power supply can reach 24V, which is relatively high; and the output current is about 1A, which is relatively small.

[0036] In this embodiment, the current sensor to be measured is a three-phase TMR current sensor.

[0037] The current chip calibration device and the data acquisition device are both directly connected to the test host, that is, the communication interfaces of the current chip calibration device and the data acquisition device are connected to the communication interface of the test host for data transmission between the two.

[0038] The output end of the test host is directly connected to the calibration test mode switching device, that is, the communication interface output end of the test host is connected to the communication input port of the calibration test mode switching device, so that the test host can control the calibration test mode switching device to realize the switching function between calibration mode and test mode.

[0039] The current sensor to be measured is connected to the current chip calibration equipment and the data acquisition equipment respectively through the calibration test mode switching device, that is, the calibration interface of the current sensor to be measured is connected to the calibration interface of the calibration test mode switching device, and the test interface of the current sensor to be measured is connected to the test interface of the calibration test mode switching device. When the system is in the calibration mode and the test mode respectively, the test host can exchange data with the corresponding interface alone, and then successfully complete the calibration process and test process processing of the current sensor to be measured, ensuring the accuracy and efficiency of the entire calibration and testing process.

[0040] The test host is directly connected to the current generating and reversing device, that is, the communication interface of the test host is connected to the communication interface of the current generating and reversing device. In this embodiment, serial port, LAN, GBIO can be used to establish communication with the test host.

[0041] The current generating and reversing device and the calibration test mode switching device are both connected to a first power supply. Specifically, the first power supply is connected to the current reversing device of the current generating and reversing device, and the first power supply is connected to the current sensor to be measured, providing power for achieving current reversal and operating the current sensor to be measured.

[0042] The calibration test mode switching device includes a test board 6, a dial switch PCB5, and a copper busbar. The test board 6 is fixedly arranged on the base 1. Specifically, the test board 6 is fixedly mounted on the base 1 through a plurality of support columns 4. The current sensor to be measured 15, the current chip calibration device, the data acquisition device, and the test host are all electrically connected to the test board 6. This connection architecture achieves an electrical path between the current sensor to be measured 15 and the current chip calibration device, as well as an electrical connection between the current sensor to be measured 15 and the data acquisition device, so that the test board 6 transmits the signal of the current sensor to be measured 15 to the current chip calibration device, the data acquisition device, and communicates with the test host. Based on such a connection system, it is possible to carry out calibration operations on the current sensor to be measured 15 and perform data acquisition work, providing basic support for subsequent data analysis and processing. Specifically, the current sensor to be measured 15 is connected to the test board 6 in the form of a connector, and the test board 6 is a circuit board.

[0043] A copper busbar mounting plate 7 is fixedly mounted above the test board 6 through the side plate 2 and the support column 3. The dip switch PCB5 is arranged on the side of the side plate 2 away from the test board 6. The dip switch PCB5 is electrically connected to the test board 6. By adjusting the position of the dip switch on the dip switch PCB5, the calibration and test mode switching control of the current sensor 15 to be measured can be realized, and the various channels of the current sensor 15 to be measured can also be switched, thereby realizing the one-by-one calibration of each channel of the current sensor 15 to be measured, effectively improving the accuracy and refinement of the calibration.

[0044] For example, in this instance, since each channel needs to be calibrated with current separately and parameters need to be written one by one when calibrating the three-phase TMR current sensor, the calibration test mode switching device adjusts the position of the dip switch on the dip switch PCB5 to switch channels after receiving the channel switching signal sent by the test host, thereby establishing communication with the current chips on the U phase (or channel 1), V phase (or channel 2) and W phase (or channel 3) channels of the three-phase TMR current sensor to realize parameter reading and writing.

[0045] The bottom of the copper busbar is fixed on the copper busbar mounting plate 7. Specifically, the copper busbar mounting plate 7 is provided with a mounting groove, and the bottom of the bent copper busbar group is fixed in the mounting groove. The copper busbar sleeve is provided with at least one current sensor 15 to be measured.

[0046] The copper busbar includes an input copper busbar 14, an output copper busbar 20, and a bent copper busbar group. One end of the bent copper busbar group is connected to the input copper busbar 14 through a copper busbar assembly 16, and the other end of the bent copper busbar group is connected to the output copper busbar 14 through a copper busbar assembly 16. A current sensor 15 to be measured is provided on the copper busbar assembly 16.

[0047] In this embodiment, the three-phase TMR current sensor is provided with three wire threading holes, which are respectively arranged on the corresponding copper sheets of the copper busbar assembly 16, so that the three-phase TMR current sensor can accurately measure the magnetic field strength generated by the current on each copper sheet, thereby realizing independent and accurate measurement of the three-phase current.

[0048] In this embodiment, if Figure 3 As shown, in actual application, multiple current sensors 15 to be measured are often installed to be calibrated and tested simultaneously, which can effectively improve production efficiency.

[0049] The current generating and switching device is connected to the calibration test mode switching device, that is, the current output end of the current generating and switching device is connected to the current input end of the calibration test mode switching device.

[0050] In this embodiment, input copper busbar 14 is connected to the output of an external current generating and reversing device. The primary current is transmitted through the busbar to the current sensor 15 to be tested, and then flows out through output copper busbar 20. Because the current chip has high sensitivity and accuracy, this embodiment achieves higher sensor accuracy during calibration testing by calibrating the sensor by simulating actual operating conditions (i.e., using the same busbar and current input method as in the application scenario).

[0051] A plurality of first positioning posts 9 are provided on the top of the copper busbar mounting plate 7, a product positioning plate 13 is provided on the top of the copper busbar, and a plurality of second positioning posts 10 are provided on the bottom of the product positioning plate 13. The first positioning posts 9 are detachably connected to the corresponding second positioning posts 10; In this embodiment, a stop block is provided on the top of the first positioning post 9, and a stop slot matching the stop block is provided at the bottom of the second positioning post 10, enabling quick positioning during assembly and disassembly of the current sensor 15 to be measured. Furthermore, a through hole matching the outer circumference of the second positioning post 10 is provided on the copper busbar assembly 16. This through hole is sleeved onto the second positioning post 10, and a side support block 11 is provided between the copper busbar mounting plate 7 and the product positioning plate 13 to provide support and stability, ensuring that the current sensor does not shift or deform during calibration and testing operations.

[0052] The device also includes a plurality of product securing blocks 8 for limiting the position of the current sensor 15 to be measured. Both ends of the product securing blocks 8 are fixedly connected to the bottom surface of the product positioning plate 13. Specifically, a securing slot is provided in the middle of the product securing block 8. When the current sensor 15 to be measured is fixedly mounted on the calibration and test mode switching device for calibration and testing, the bottom surface of the securing slot abuts the bottom of the current sensor 15 to be measured. This ensures that the current sensor to be measured does not move or deform during calibration and testing. This is particularly effective for position-sensitive current sensors (such as those based on the TMR principle), preventing poor sensor accuracy due to differences between the test environment and actual operating conditions.

[0053] The current generating and commutating device includes a second power supply, an electronic load, and a current commutating device. The current generating and commutating device used in this embodiment establishes communication with a test host, enabling the test host to control the device to generate any desired primary current and adjust the current magnitude and direction at any time. Specifically, the second power supply outputs a relatively low maximum voltage of 10V, while the output current can reach a relatively high maximum of 1000A.

[0054] The above-mentioned electronic load can simulate the load of the three-phase TMR current sensor in actual use to calibrate and test the three-phase TMR current sensor. Through this simulation, the performance of the three-phase TMR current sensor in actual working scenarios can be measured more realistically, ensuring that it can accurately measure current even when facing complex and changeable loads, effectively improving the accuracy of the current sensor calibration and test results.

[0055] The stable DC generated by the second power supply is transmitted through the electronic load to the current reversing device. After receiving the forward or reverse current signal sent by the test host, the device switches the current direction, thereby generating primary currents of different directions required for calibrating and testing the three-phase TMR current sensor.

[0056] In this embodiment, the above-mentioned current generating and commutating device has the following advantages: ①The device has a certain voltage output capability (such as 10V), and can still output the set current when the external current copper busbar impedance is large; ②The device has good current stability, ensuring low current ripple (≤0.2A) during the test. ③The device has the ability to respond quickly and establish a stable current. After the current is set, the current output stabilizes to the set value within a certain period of time (≤0.1s); ④The device has the ability to convert the direction of current and can switch the current direction after receiving the current forward or current reverse signal sent by the test host.

[0057] The current chip calibration device includes a data collector and a burner. The data acquisition port of the data collector is directly connected to the Vout port of the current sensor current chip to be tested, and is used to collect the output voltage of the current sensor current chip to be tested during the test process for subsequent data analysis; The Vout port of the current sensor current chip to be measured is directly connected to the input port of the writer, so as to write data to the current sensor current chip to be measured during the calibration process.

[0058] Specifically, the current chip calibration equipment establishes communication with the three-phase TMR current sensor under test (the sensor being tested) by connecting the VCC, GND, and OUT pins of the current chip. During calibration, a data logger collects the output voltages of each pin and calculates the current chip's zero-point parameters, which meet the accuracy requirements, before transmitting them to the test host for data analysis. These parameters are then written to the current chip via a programmer according to the chip's communication protocol.

[0059] The data acquisition device has multi-channel acquisition, and the number of acquisition channels is ≥4, the acquisition accuracy is ≥0.1%, and the sampling rate is ≥1ksps.

[0060] In this embodiment, the model of the data acquisition device used is DAQ973A / USB-6451, and the input voltage range is within 5V. After the signal acquisition is completed, the data is packaged and sent to the test host.

[0061] The method for calibrating the test system includes the following steps: 1) A judgment module is set in the calibration test system software set in the test host, and a zero point parameter threshold is set in the judgment module to determine whether the current sensor meets production requirements during the preliminary test of the current sensor to be tested; 2) Install the current sensor to be tested on the calibration test mode switching device. The test host switches the calibration test mode switching device to the test mode by adjusting the position of the dip switch on the dip switch PCB, and controls the current generation and reversing device to generate the primary current of different magnitudes and directions required for the test. Specifically, the current sensor to be tested is fixed to the copper busbar of the calibration test mode switching device. Upon receiving a switching signal from the test host, the calibration test mode switching device controls the electrical switching devices within it (such as relays, analog switches, and cylinders) to complete the switching action. After the switching is complete, the entire circuit is self-tested. This avoids the traditional method of using connectors to switch between the calibration plug and the test plug, which can lead to loose connections due to the connector's lifespan. This effectively increases the reliability of current sensor calibration testing and significantly improves efficiency.

[0062] In this embodiment, the test host controls the position of the dip switch on the dip switch PCB to control the calibration and test mode switching of the sensor, as well as the switching of each channel of the sensor, thereby realizing one-by-one calibration of each channel of the three-phase TMR current sensor.

[0063] 3) using a data collector to collect the zero-point parameter of the current sensor to be measured, and comparing the obtained zero-point parameter with the zero-point parameter threshold; In this embodiment, the zero point parameter threshold is determined according to production requirements.

[0064] 4) According to the judgment result of step 3), if the zero point parameter ≠ the zero point parameter threshold, the position of the DIP switch is changed to switch the state of the calibration test mode switching device to the calibration mode, and the zero point parameter is written into the current chip; 5) Parameter thresholds are also provided, including an accuracy threshold, a linearity threshold, a zero point threshold, and a gain parameter threshold, which serve as a basis for determining whether the calibrated current sensor meets the accuracy requirements; 6) The test host switches the state of the calibration test mode switching device to the test mode by adjusting the position of the dip switch on the dip switch PCB, and controls the current generation and reversing device to generate the primary current of different magnitudes and directions required for the test; 7) Using a data acquisition device to test the current sensor to be tested, collecting output voltage and resistance data of the current sensor to be tested under different primary currents, and transmitting the data to a test host for analysis and calculation to obtain test data of the current sensor to be tested, wherein the test data includes accuracy, linearity, zero point parameters, and gain parameters; 8) Compare the test data of the current sensor to be tested with the standard threshold values of various parameters to determine whether the calibrated current sensor to be tested meets the requirements, and display the status of the current sensor to be tested on the display. The specific method is as follows: 8-1) If it meets the requirements, the display will show that the current sensor to be tested is normal; 8-2) If it does not meet the requirements, the display will show that the current sensor to be tested is abnormal, and the above steps 3) to 7) will be repeated.

[0065] In this embodiment, when the number of repetitions is ≥2, it is determined that the current sensor to be tested is faulty.

[0066] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications made to the present invention by those skilled in the art without departing from the spirit of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A calibration and testing system for a three-phase TMR current sensor, characterized in that: Also includes: The test host is used to control the calibration test system to realize the calibration and test functions of the current sensor to be tested; A calibration test mode switching device, used for switching the calibration and test modes of the calibration test system for the current sensor to be tested; Current chip calibration equipment, used to calibrate the parameters of the current chip of the current sensor to be tested; A current generating and reversing device, used to generate primary currents of different directions required in the process of testing the current sensor to be tested; A data acquisition device is used to collect the output voltage signal of the current sensor to be tested and transmit the collected voltage signal to the test host; A first power supply is used to supply power to the current generating and switching device, the calibration test mode switching device and the current sensor to be measured; The current chip calibration device and the data acquisition device are both directly connected to the test host, the output end of the test host is directly connected to the calibration test mode switching device, and the current sensor to be tested is respectively connected to the current chip calibration device and the data acquisition device through the calibration test mode switching device, the test host is directly connected to the current generating and reversing device, the current generating and reversing device is connected to the calibration test mode switching device, and the current generating and reversing device and the calibration test mode switching device are both connected to the first power supply.

2. The calibration and testing system for a three-phase TMR current sensor according to claim 1, characterized in that: The current generating and commutating device includes a second power supply, an electronic load, and a current commutating device, wherein the second power supply is used to generate the primary current required for testing the current sensor to be tested; The electronic load is used to protect the circuit and simulate the actual load during the use of the current sensor to be measured; The current reversing device is used to change the direction of the primary current; The second power supply is connected to the current reversing device through an electronic load, and the current output end of the current reversing device is connected to the copper bus of the calibration test mode switching device.

3. The calibration and testing system for a three-phase TMR current sensor according to claim 1, characterized in that: The current chip calibration device includes a data collector and a burner. The data acquisition port of the data collector is directly connected to the Vout port of the current sensor current chip to be tested, and is used to collect the output voltage of the current sensor current chip to be tested during the test process for subsequent data analysis; The Vout port of the current sensor current chip to be measured is directly connected to the input port of the writer, so as to write data to the current sensor current chip to be measured during the calibration process.

4. The calibration and testing system for a three-phase TMR current sensor according to claim 1, characterized in that: The data acquisition device has multi-channel acquisition, and the number of acquisition channels is ≥4, the acquisition accuracy is ≥0.1%, and the sampling rate is ≥1ksps.

5. The calibration and testing system for a three-phase TMR current sensor according to claim 1, characterized in that: The calibration test mode switching device comprises a test board (6), a dip switch PCB (5), and a copper busbar. The test board (6) is fixedly arranged on a base (1). A copper busbar mounting plate (7) is fixedly mounted above the test board (6) via a side plate (2) and a support column (3). The dip switch PCB (5) is arranged on a side of the side plate (2) away from the test board (6). The dip switch PCB (5) is electrically connected to the test board (6). The copper busbar is fixedly arranged on the copper busbar mounting plate (7) and is used for mounting a current sensor (15) to be measured.

6. The calibration and testing system for a three-phase TMR current sensor according to claim 5, characterized in that: A plurality of first positioning columns (9) are provided on the top of the copper busbar mounting plate (7), a product positioning plate (13) is provided on the top of the copper busbar, and a plurality of second positioning columns (10) are provided on the bottom of the product positioning plate (13), and the first positioning columns (9) are detachably connected to the corresponding second positioning columns (10); It also includes a plurality of product fixing blocks (8) for limiting the current sensor (15) to be measured, and both ends of the product fixing blocks (8) are fixedly connected to the bottom surface of the product positioning plate (13).

7. The calibration and testing system for a three-phase TMR current sensor according to claim 5, characterized in that: The copper busbar comprises an input copper busbar (14), an output copper busbar (20), and a bent copper busbar group. One end of the bent copper busbar group is connected to the input copper busbar (14) via a copper busbar assembly (16), and the other end of the bent copper busbar group is connected to the output copper busbar (14) via a copper busbar assembly (16). A current sensor (15) to be measured is provided on the copper busbar assembly (16).

8. The calibration and testing system for a three-phase TMR current sensor according to claim 5, characterized in that: The current sensor to be tested (15), the current chip calibration device, the data acquisition device, and the test host are all electrically connected to the test board (6).

9. A method for testing and calibrating a current sensor using the calibration test system according to claim 1, characterized in that: The following steps are involved: 1) A judgment module is set in the calibration test system software set in the test host, and a zero point parameter threshold is set in the judgment module to determine whether the current sensor meets production requirements during the preliminary test of the current sensor to be tested; 2) Install the current sensor to be tested on the calibration test mode switching device. The test host switches the calibration test mode switching device to the test mode by adjusting the position of the dip switch on the dip switch PCB, and controls the current generation and reversing device to generate the primary current of different magnitudes and directions required for the test. 3) using a data collector to collect the zero-point parameter of the current sensor to be measured, and comparing the obtained zero-point parameter with the zero-point parameter threshold; 4) According to the judgment result of step 3), change the position of the DIP switch to switch the state of the calibration test mode switching device to the calibration mode, and write the zero point parameter into the current chip; 5) Parameter thresholds are also provided, including an accuracy threshold, a linearity threshold, a zero point threshold, and a gain parameter threshold, which serve as a basis for determining whether the calibrated current sensor meets the accuracy requirements; 6) The test host switches the state of the calibration test mode switching device to the test mode by adjusting the position of the dip switch on the dip switch PCB, and controls the current generation and reversing device to generate the primary current of different magnitudes and directions required for the test; 7) Using a data acquisition device to test the current sensor to be tested, collecting output voltage and resistance data of the current sensor to be tested under different primary currents, and transmitting the data to a test host for analysis and calculation to obtain test data of the current sensor to be tested, wherein the test data includes accuracy, linearity, zero point parameters, and gain parameters; 8) Compare the test data of the current sensor to be tested with the standard threshold values of various parameters to determine whether the calibrated current sensor to be tested meets the requirements.

10. The method according to claim 9, characterized in that In step 8), the test data of the current sensor to be tested is compared with the standard threshold values of various parameters to determine whether the calibrated current sensor to be tested meets the requirements, and the specific method of displaying the status of the current sensor to be tested on the display is as follows: 8-1) If it meets the requirements, the display will show that the current sensor to be tested is normal; 8-2) If it does not meet the requirements, the display will show that the current sensor to be tested is abnormal, and the above steps 3) to 7) will be repeated.

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