High-voltage isolation clamp for testing port network parameters of electric drive system module

Abstract

The utility model relates to the technical field of testing devices, and discloses a high-voltage isolation clamp for testing port network parameters of an electric drive system module, which comprises a PCB (printed circuit board). A high-voltage isolation circuit is arranged on the PCB; the high-voltage isolation circuit comprises a plurality of parallel branches; the parallel branch is an RC circuit; a capacitor, a resistor, an input port and a connecting port are arranged in each RC circuit; the input port is used for being connected with a vector network analyzer; the connecting port is used for being connected with a module port cable or a connector. According to the utility model, damage of high-voltage electricity to test equipment can be effectively isolated, and test safety and test reliability are ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of test devices, and particularly relates to a high-voltage isolation fixture for testing port network parameters of an electric drive system module. Background Art

[0002] When performing simulation prediction on the electromagnetic compatibility (EMC) performance of an automotive electric drive system, if reliable prediction results are to be obtained, an accurate high-frequency equivalent model of the entire system needs to be established. The core of this model lies in obtaining the port network parameters of each module of the system (such as high-voltage DC power supply, DC / AC inverter, motor, etc.), especially impedance and S parameters, which reflect the behavioral characteristics of the module under high-frequency operating conditions.

[0003] Currently, for the measurement of port network parameters of electric drive system modules, the single-port impedance test method for motors in the industry has been relatively mature, but these tests are usually carried out in a stationary state with the electric drive system powered off. This method has great limitations. Especially when facing active modules (such as high-voltage DC power supply, DC / AC inverter), the measurement results under static conditions may be very different from the parameters under actual operating conditions. This is because under high-voltage power supply and actual operating conditions, the internal non-linear elements and switching behaviors of active modules will cause changes in dynamic impedance and S parameters, which cannot be reflected under the power-off condition.

[0004] For passive modules, such as motors, simple single-port impedance tests also cannot fully reflect the coupling effects in their complex internal structures. There are parasitic capacitances and mutual inductances between the windings of the motor and between the windings and the housing, and these factors have an important impact on electromagnetic compatibility at high frequencies. Therefore, relying solely on single-port impedance tests is not sufficient to comprehensively describe the port characteristics of the module, and more complex multi-port network parameter measurements are required to capture these internal coupling effects.

[0005] The automotive electric drive system operates under a high-voltage DC power supply of about 800V. Against the background of high-voltage DC power supply, the operating environment of the electric drive system poses additional challenges to testing. Since high-voltage DC and AC can cause great damage to test equipment, it is impossible to directly measure the port network parameters of the electric drive system under the power-on condition. This requires researchers and engineers to develop new test technologies and methods to measure as close as possible to the actual operating conditions while ensuring safety. Summary of the Utility Model

[0006] The utility model aims to provide a high-voltage isolation fixture for testing port network parameters of an electric drive system module, which can effectively isolate the damage of high-voltage electricity to test equipment and ensure test safety and reliability.

[0007] The basic solution provided by the present utility model is as follows: A high-voltage isolation fixture for testing the port network parameters of an electric drive system module, including a PCB board; a high-voltage isolation circuit is provided on the PCB board; the high-voltage isolation circuit includes a plurality of parallel branches; the parallel branches are RC circuits; in each RC circuit, a capacitor, a resistor, an input port, and a connection port are provided; the input port is used to connect to a vector network analyzer; the connection port is used to connect to a module port cable or connector.

[0008] Further, the RC circuit includes a first RC circuit; in the first RC circuit, it includes: resistor Ra is in series with capacitor C1, resistor Ra, capacitor C1, and resistor R7 are in parallel, and resistor R7 is grounded; the input port port1 is connected between resistor Ra and capacitor C1, and the connection port SMA1 is in series with capacitor C1.

[0009] Further, the RC circuit further includes a second RC circuit; in the second RC circuit, it includes: resistor Rb is in series with capacitor C2, resistor Rb, capacitor C2, and resistor R8 are in parallel, and resistor R8 is grounded; the input port port2 is connected between resistor Rb and capacitor C2, and the connection port SMA2 is in series with capacitor C2.

[0010] Further, the RC circuit further includes a third RC circuit; in the third RC circuit, it includes: resistor R1 and resistor R2 are in parallel and then in series with capacitor C3, capacitor C3 is in parallel with resistor R9, and resistor R9 is grounded; the input port port3 is connected between resistor R1, resistor R2, and capacitor C3, and the connection port SMA3 is in series with capacitor C3.

[0011] Further, the RC circuit further includes a fourth RC circuit; in the fourth RC circuit, it includes: resistor R3 and resistor R4 are in parallel and then in series with capacitor C4, capacitor C4 is in parallel with resistor R10, and resistor R10 is grounded; the input port port4 is connected between resistor R3, resistor R4, and capacitor C4, and the connection port SMA4 is in series with capacitor C4.

[0012] Further, the RC circuit further includes a fifth RC circuit; in the fifth RC circuit, it includes: resistor R5 and resistor R6 are in parallel and then in series with capacitor C5, capacitor C5 is in parallel with resistor R11, and resistor R11 is grounded; the input port port5 is connected between resistor R5, resistor R6, and capacitor C5, and the connection port SMA5 is in series with capacitor C5.

[0013] Further, the resistance values of resistor Ra and resistor Rb are both 20KΩ.

[0014] Further, the resistance values of resistor R7, resistor R8, resistor R9, resistor R10, and resistor R11 are all 100KΩ.

[0015] Further, the resistance values of the resistor R1, resistor R2, resistor R3, resistor R4, resistor R5 and resistor R6 are all 2 MΩ.

[0016] Further, the capacitance values of the capacitor C1, capacitor C2, capacitor C3, capacitor C4 and capacitor C5 are all 0.1 μf.

[0017] The working principle and advantages of the present utility model are as follows:

[0018] The present utility model is a high-voltage isolation fixture for testing the port network parameters of an electric drive system module, which designs a high-voltage isolation circuit. It can connect a VNA (Vector Network Analyzer) directly to the module cable for testing, and can isolate the damage of high voltage to the test equipment, realizing the multi-port network parameter testing of the active module under the on-site working condition of the power grid. Moreover, this high-voltage isolation fixture integrates the isolation circuits of the active module and the passive module on a circuit board (for the active module, the isolation circuit can disconnect the high-voltage end of the high-voltage component from the VNA, making the RF terminal of the VNA adapt to the module port cable / connector; for the passive module, the isolation circuit can also directly make the RF terminal of the VNA adapt to the module port cable / connector), which can save the cost of making the board. And it can use the same ports to test multiple modules, and is not limited to the testing of the electric drive system module, with strong versatility.

[0019] In specific applications, such as in the measurement of the port network parameters of the electric drive system module, the vector network analyzer can be connected to this high-voltage isolation fixture and then connected to the automotive electric drive system through the module port cable or connector, and the S-parameter matrices of the DC terminal of the inverter, the AC terminal of the inverter, the power supply and the motor can be tested respectively; realizing the parameter measurement under the working state of the automotive electric drive system and the high-voltage power supply working condition. Among them, the capacitors C1, C2, C3, C4, C5 can play the role of blocking direct current; the resistors R1, R2, R3, R4, R5 and R6 can play the role of reducing current; together with other resistors, the resistors Ra and Rb can meet the power requirements of the high-voltage circuit; the resistors R7, R8, R9, R10 and R11 can make the direct current or static electricity coming from the SMA interface grounded; the overall fixture can withstand a high voltage of 1000 V. Description of the Drawings

[0020] Figure 1 It is the schematic diagram of the high-voltage isolation circuit of the embodiment of a high-voltage isolation fixture for testing the port network parameters of an electric drive system module of the present utility model;

[0021] Figure 2 It is the schematic diagram of the PCB board structure of the embodiment of a high-voltage isolation fixture for testing the port network parameters of an electric drive system module of the present utility model. Detailed Implementation Modes

[0022] The following provides a more detailed description through specific implementation modes:

[0023] The embodiment is basically as shown in the attached Figure 1 、 Figure 2 : A high-voltage isolation fixture for testing the port network parameters of an electric drive system module, including a PCB board; a high-voltage isolation circuit is provided on the PCB board; the high-voltage isolation circuit includes a plurality of parallel branches; the parallel branches are RC circuits; in each RC circuit, a capacitor, a resistor, an input port, a connection port, and a grounding path (GND) are provided; the input port is used to connect to a vector network analyzer; the connection port is used to connect to a module port cable or connector.

[0024] The RC circuit includes a first RC circuit, a second RC circuit, a third RC circuit, a fourth RC circuit, and a fifth RC circuit.

[0025] In the first RC circuit, it includes: resistor Ra is in series with capacitor C1, resistor Ra, capacitor C1, and resistor R7 are in parallel, and resistor R7 is grounded; input port port1 is connected between resistor Ra and capacitor C1, and connection port SMA1 is in series with capacitor C1.

[0026] In the second RC circuit, it includes: resistor Rb is in series with capacitor C2, resistor Rb, capacitor C2, and resistor R8 are in parallel, and resistor R8 is grounded; input port port2 is connected between resistor Rb and capacitor C2, and connection port SMA2 is in series with capacitor C2.

[0027] In the third RC circuit, it includes: resistor R1 and resistor R2 are in parallel and then in series with capacitor C3, capacitor C3 is in parallel with resistor R9, and resistor R9 is grounded; input port port3 is connected between resistor R1, resistor R2, and capacitor C3, and connection port SMA3 is in series with capacitor C3.

[0028] In the fourth RC circuit, it includes: resistor R3 and resistor R4 are in parallel and then in series with capacitor C4, capacitor C4 is in parallel with resistor R10, and resistor R10 is grounded; input port port4 is connected between resistor R3, resistor R4, and capacitor C4, and connection port SMA4 is in series with capacitor C4.

[0029] In the fifth RC circuit, it includes: resistor R5 and resistor R6 are in parallel and then in series with capacitor C5, capacitor C5 is in parallel with resistor R11, and resistor R11 is grounded; input port port5 is connected between resistor R5, resistor R6, and capacitor C5, and connection port SMA5 is in series with capacitor C5.

[0030] In the above circuit, port1, port2, port3, port4, and port5 all refer to the physical interfaces or ports on a network device. They are usually used to connect different devices so that data transmission and communication can occur between them. Each interface typically has a unique identifier for identification. Port1 to port5 can be different types of interfaces, such as Ethernet ports, USB ports, serial ports, etc., depending on the device type and usage. Using these ports, devices can perform operations such as data exchange, resource sharing, and file transfer. SMA refers to the SMA connector interface, that is, the interface of the SMA type coaxial connector. SMA is a small-sized radio frequency coaxial connector widely used in high-frequency electronic devices, such as radio communication, radar systems, test instruments, and microwave devices, etc.

[0031] From the port to the corresponding SMA (such as port1 corresponding to SMA1, port2 corresponding to SMA2, etc.), capacitors C1, C2, C3, C4, and C5 function to block direct current. The operating frequency of the alternating current signal is 150KHz - 500MHz, then the corresponding capacitance value can be selected as 0.1uF, that is, the capacitance values of the capacitors C1, C2, C3, C4, and C5 are all 0.1μF; with such a setting, within the required frequency range, the amplitude-frequency characteristic is good. Considering the breakdown voltage of the capacitor, capacitors C1, C2, C3, C4, and C5 are all selected as high-voltage chip capacitors with a maximum operating voltage of over 1000V, and the package is selected as 1812 (that is, the package size of 18×12 is selected).

[0032] The resistance values of the resistors R1, R2, R3, R4, R5, and R6 are all 2MΩ, which can play a role in reducing the current. Based on Imax = Umax / R, taking Umax = 1000V as an example (since the automotive electric drive system operates under a high-voltage direct current supply of approximately 800V, taking 1000V as an example here can effectively verify the effectiveness of this high-voltage isolation circuit), then the corresponding Imax = 1000V / 2MΩ = 0.5mA, Pmax = 1000V * 1000V / 2MΩ = 0.5W. Considering that the power tolerance of a resistor with a 2512 package (that is, the package size is 25×12) is 1W, it meets the power requirement. In this embodiment, resistors R1, R2, R3, R4, R5, and R6 are all selected as 2512 packages, and high-voltage chip resistors with a maximum operating voltage of over 1000V are selected.

[0033] The resistance values of the resistor Ra and the resistor Rb are both 20 KΩ; in this embodiment, the resistor Ra and the resistor Rb are high-voltage color ring resistors with a maximum operating voltage of over 1000 V and a power of 1 W. Taking Umax = 1000 V as an example, Pmax = (0.5 mA * 3) * (0.5 mA * 3) * 20 KΩ = 0.045 W, and the components selected in this embodiment can meet the power requirements.

[0034] The resistance values of the resistor R7, the resistor R8, the resistor R9, the resistor R10, and the resistor R11 are all 100 KΩ, which can make the DC or static electricity coming from the SMA interface grounded. And, in this embodiment, the resistor R7, the resistor R8, the resistor R9, the resistor R10, and the resistor R11 all adopt 2512 package, that is, the package size is 25×12; the maximum operating voltage is over 1000 V.

[0035] The operating frequency range of the SMA interface (including SMA1 to SMA5) is DC - 6 GHz, which meets the signal operating frequency of 150 KHz - 500 MHz, and the dielectric withstand voltage is greater than or equal to 2500 V. The port wiring terminals (including port1 to port5) only need to meet the maximum operating current.

[0036] In addition, in this embodiment, the PCB board uses FR4 material with a thickness of 1.6 mm. The breakdown voltage of the epoxy resin used in the FR4 material is 30 KV / MM. The line spacing between the lines on the PCB board is more than 1 mm, and the line width is 2 mm to meet the high-voltage insulation and current-carrying capacity.

[0037] In specific applications, a vector network analyzer can be connected to this high-voltage isolation fixture and then connected to the automotive electric drive system through a module port cable or connector, and the S-parameter matrices of the DC side of the inverter, the AC side of the inverter, the power supply, and the motor can be tested respectively.

[0038] A high-voltage isolation fixture provided in this embodiment for testing the network parameters of the module ports of the electric drive system can effectively isolate the damage of high-voltage electricity to the test equipment, can realize the multi-port network parameter testing of the active module under the on-site working conditions, and ensure the test safety and test reliability.

[0039] The above are only the embodiments of the present utility model. Specific structures and characteristics and other common knowledge in the art are not described in detail herein. Those of ordinary skill in the art know all the general technical knowledge in the technical field to which the utility model belongs before the application date or the priority date, can learn all the prior arts in this field, and have the ability to apply the conventional experimental means before this date. Those of ordinary skill in the art can, under the inspiration given in this application, combine their own abilities to complete and implement this solution. Some typical well-known structures or well-known methods should not become obstacles for those of ordinary skill in the art to implement this application. It should be noted that for those skilled in the art, without departing from the structure of the present utility model, several deformations and improvements can also be made, and these should also be regarded as the protection scope of the present utility model, and these will not affect the implementation effect of the present utility model and the practicality of the patent.

Claims

1. A high-voltage isolation fixture for testing network parameters of electric drive system module ports, characterized in that: It comprises a PCB board; a high-voltage isolation circuit is arranged on the PCB board; the high-voltage isolation circuit comprises a plurality of parallel branches; the parallel branches are RC circuits; each RC circuit is provided with a capacitor, a resistor, an input port and a connection port; the input port is used to connect to a vector network analyzer; the connection port is used to connect to a module port cable or a connector.

2. A high-voltage isolation fixture for testing network parameters of an electric drive system module port according to claim 1, characterized in that: The RC circuit includes a first RC circuit; in the first RC circuit, it includes: a resistor Ra is connected in series with a capacitor C1, a resistor Ra, a capacitor C1 and a resistor R7 are connected in parallel, and a resistor R7 is grounded; an input port port1 is connected between the resistor Ra and the capacitor C1, and a connection port SMA1 is connected in series with the capacitor C1.

3. A high-voltage isolation fixture for testing network parameters of an electric drive system module port according to claim 2, characterized in that: The RC circuit also includes a second RC circuit; in the second RC circuit, it includes: a resistor Rb and a capacitor C2 are connected in series, a resistor Rb, a capacitor C2 and a resistor R8 are connected in parallel, and a resistor R8 is grounded; an input port port2 is connected between the resistor Rb and the capacitor C2, and a connection port SMA2 is connected in series with the capacitor C2.

4. A high-voltage isolation fixture for testing network parameters of an electric drive system module port according to claim 3, characterized in that: The RC circuit also includes a third RC circuit; in the third RC circuit, it includes: resistor R1 and resistor R2 are connected in parallel and then in series with capacitor C3, capacitor C3 and resistor R9 are connected in parallel, and resistor R9 is grounded; input port port3 is connected between resistor R1, resistor R2 and capacitor C3, and connection port SMA3 is connected in series with capacitor C3.

5. A high-voltage isolation fixture for testing network parameters of an electric drive system module port according to claim 4, characterized in that: The RC circuit also includes a fourth RC circuit; in the fourth RC circuit, it includes: resistor R3 and resistor R4 are connected in parallel and then in series with capacitor C4, capacitor C4 and resistor R10 are connected in parallel, and resistor R10 is grounded; input port port4 is connected between resistor R3, resistor R4 and capacitor C4, and connection port SMA4 is connected in series with capacitor C4.

6. A high-voltage isolation fixture for testing network parameters of an electric drive system module port according to claim 5, characterized in that: The RC circuit further includes a fifth RC circuit; In the fifth RC circuit, it includes: resistor R5 and resistor R6 are connected in parallel and then in series with capacitor C5, capacitor C5 and resistor R11 are connected in parallel, and resistor R11 is grounded; input port port5 is connected between resistor R5, resistor R6 and capacitor C5, and connection port SMA5 is connected in series with capacitor C5.

7. A high-voltage isolation fixture for testing network parameters of an electric drive system module port according to claim 3, characterized in that: The resistance values ​​of the resistor Ra and the resistor Rb are both 20KΩ.

8. A high-voltage isolation fixture for testing network parameters of an electric drive system module port according to claim 6, characterized in that: The resistance values ​​of the resistors R7 , R8 , R9 , R10 and R11 are all 100KΩ.

9. A high-voltage isolation fixture for testing network parameters of an electric drive system module port according to claim 6, characterized in that: The resistance values ​​of the resistors R1 , R2 , R3 , R4 , R5 and R6 are all 2 MΩ.

10. A high-voltage isolation fixture for testing network parameters of an electric drive system module port according to claim 6, characterized in that: The capacitance values ​​of the capacitors C1 , C2 , C3 , C4 and C5 are all 0.1 μF.

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