IGBT test system and method

Abstract

The invention relates to an IGBT (Insulated Gate Bipolar Translator) test system and method, which can improve the IGBT test efficiency and safety. The IGBT test system comprises a signal switching module, an IGBT test circuit, a driving module and a controller, the signal switching module and the driving module are both connected with the IGBT test circuit, and the signal switching module, the driving module and the IGBT test circuit are all connected with the controller.

Description

Technical Field

[0001] The present disclosure relates to the field of power electronics technology, and in particular, to an IGBT testing system and method. Background Art

[0002] With the development of modern power electronics technology, especially its wide application in energy conversion, transmission and control systems, the converter, as the core equipment, plays a vital role. In the working principle of the converter, IGBT (insulated gate bipolar transistor), as an important semiconductor device, is often used as a switching device to achieve the conversion, control and regulation of electric energy. However, the performance of IGBT directly affects the working efficiency, reliability and performance of the converter in practical applications. Therefore, dynamic and static detection of IGBT has important theoretical value and practical significance for ensuring the reliable operation of the converter, improving the stability of the system and extending the service life.

[0003] In the related art, the testing equipment lacks the comprehensive testing capability for the static and dynamic characteristics of IGBT, and the testing process requires frequent manual intervention, resulting in low testing efficiency and safety risks. Summary of the invention

[0004] The purpose of the present disclosure is to provide an IGBT testing system and method to solve the problems in the related art.

[0005] In order to achieve the above-mentioned object, in a first aspect, the present disclosure provides an IGBT test system, the IGBT test system comprising: a signal switching module, an IGBT test circuit, a drive module and a controller; The signal switching module and the driving module are both connected to the IGBT test circuit, and the signal switching module, the IGBT test circuit and the driving module are all connected to the controller.

[0006] Optionally, the IGBT test circuit includes an IGBT module to be tested, and the IGBT module to be tested includes a first IGBT to be tested and a second IGBT to be tested; The first IGBT to be tested and the second IGBT to be tested are connected in series to form a half-bridge arm circuit structure; The gate of the first IGBT to be tested and the gate of the second IGBT to be tested are both connected to the driving module.

[0007] Optionally, the IGBT test circuit includes a capacitor and an inductor; The first end of the capacitor is connected to the collector of the first IGBT to be tested, and the second end of the capacitor is connected to the emitter of the second IGBT to be tested; The inductor is connected in series with the IGBT module to be tested.

[0008] Optionally, the IGBT test circuit includes a first relay, a second relay and a third relay; The control end of the first relay, the control end of the second relay and the control end of the third relay are all connected to the signal switching module; The first relay is arranged on the branch where the capacitor is located, the second relay is arranged on the branch between the first IGBT to be tested and the inductor, and the third relay is arranged on the branch between the second IGBT to be tested and the inductor.

[0009] Optionally, the IGBT test circuit includes a power supply module; The positive electrode of the power module is connected to the collector of the first IGBT to be tested, and the negative electrode of the power module is connected to the emitter of the second IGBT to be tested; The control end of the power module is connected to the controller.

[0010] Optionally, the system further comprises a communication module; The controller sends the voltage information and current information of the IGBT module to be tested to the target host computer through the communication module, and receives the instruction information sent by the target host computer.

[0011] In a second aspect, the present disclosure provides an IGBT testing method, applied to the IGBT testing system described in any one of the first aspects, the method comprising: The controller determines a target test object of the IGBT module to be tested in response to a target test type instruction sent by the target host computer, wherein the target test type includes a static test and a dynamic test, and the target test object includes a first IGBT to be tested and a second IGBT to be tested; The controller controls the first relay, the second relay and the third relay in the IGBT test circuit to reach the corresponding target open and close states through the signal switching module according to the target test type and the target test object; When the target open / close state is reached, the controller adjusts the output voltage of the power module according to a preset time interval and a preset step amount, and sends the collected current voltage value of the target test object to the target host computer according to the preset time interval; The target host computer determines a test result of the target test object according to the output voltage and the current voltage value.

[0012] Optionally, the controller controls the first relay, the second relay, and the third relay in the IGBT test circuit to reach corresponding target open and close states through a signal switching module according to the target test type and the target test object, including: In the case where the target test type is a static test, the controller determines the target test object as the first IGBT to be tested, controls the first relay to be in an open state, the second relay to be in an open state, and the third relay to be in a closed state through the signal switching module, and in the case where the first IGBT to be tested passes the static test, determines the target test object as the second IGBT to be tested, controls the first relay to be in an open state, the second relay to be in a closed state, and the third relay to be in an open state through the signal switching module; When the target test type is a dynamic test, the controller determines the target test object as the first IGBT to be tested, and controls the first relay to be in a closed state, the second relay to be in an open state, and the third relay to be in a closed state through the signal conversion module. When the first IGBT to be tested passes the dynamic test, the target test object is determined to be the second IGBT to be tested, and the first relay is controlled to be in a closed state, the second relay to be in a closed state, and the third relay to be in an open state through the signal conversion module.

[0013] Optionally, the target host computer determines the test result of the target test object according to the output voltage and the current voltage value, including: The controller sends the current voltage value of the target test object collected at each preset time interval to the target host computer, and the target host computer determines whether the current voltage value is within a first preset range. If the target host computer determines that the current voltage value is within the preset voltage range, the controller controls the output voltage to increase according to the preset time interval and the preset step amount, and sends the collected current voltage value of the target test object to the target host computer according to the preset time interval until the output voltage reaches a preset voltage threshold; When the target test type is a static test and the output voltage reaches a preset voltage threshold, the controller sends the collected voltage value of the target test object within a preset time length to the target host computer, and the target host computer determines whether the voltage value within the preset time length is within a second preset range; If the voltage value within the preset time period is within the second preset range, the target host computer determines that the target test object passes the static test; If either the current voltage value is not within the first preset voltage range or the voltage value within the preset time period is not within the second preset voltage range, the target host computer determines that the target test object has failed the static test and sends a current limiting protection instruction to the controller.

[0014] Optionally, the method further comprises: When the target test type is a dynamic test and the output voltage reaches a preset voltage threshold, the controller controls the driving module to output a driving signal to the target test object, and sends the voltage waveform and current waveform of the target test object collected according to the driving signal to the target host computer, and the target host computer determines whether the voltage waveform and the current waveform have abnormal characteristics according to a preset waveform standard; If the voltage waveform and the current waveform do not have the abnormal feature, the target host computer determines that the target test object passes the dynamic test; If any one of the following conditions is met: the current voltage value is not within the first preset voltage range, and the voltage waveform and / or the current waveform has the abnormal characteristics, the target host computer determines that the target test object has failed the dynamic test and sends a current limiting protection instruction to the controller.

[0015] Through the above technical scheme, the IGBT test system disclosed in the present invention may include a signal conversion module, an IGBT test circuit, a drive module and a controller, wherein the signal conversion module and the drive module are both connected to the IGBT test circuit, and the signal conversion module, the IGBT test circuit and the drive module are all connected to the controller, so that integrated unified control can be achieved, and the target test object in the IGBT test circuit can be quickly switched between dynamic and static test modes through the signal conversion module and the drive module, thereby effectively improving the efficiency and safety of IGBT testing.

[0016] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings: Figure 1 It is a schematic diagram showing an IGBT testing system according to an exemplary embodiment of the present disclosure.

[0018] Figure 2 It is a structural schematic diagram of an IGBT test circuit according to an exemplary embodiment of the present disclosure.

[0019] Figure 3 The figure is a flow chart of an IGBT testing method according to an exemplary embodiment of the present disclosure.

[0020] Figure 4 The figure is a flow chart of an IGBT static testing method according to an exemplary embodiment of the present disclosure.

[0021] Figure 5 The figure is a flow chart of an IGBT dynamic testing method according to an exemplary embodiment of the present disclosure.

[0022] Description of Reference Numerals Signal transfer module-110; IGBT test circuit-120; drive module-130; controller-140; first IGBT to be tested-11; second IGBT to be tested-12; capacitor-13; inductor-14; first relay-15; second relay-16; third relay-17. DETAILED DESCRIPTION

[0023] The specific implementation of the present disclosure is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described herein is only used to illustrate and explain the present disclosure, and is not used to limit the present disclosure.

[0024] As mentioned in the background technology, in the related art, the testing equipment lacks the comprehensive testing capability for the static and dynamic characteristics of IGBT, and the testing process requires frequent manual intervention, resulting in low testing efficiency and safety risks.

[0025] In view of this, the embodiments of the present disclosure provide an IGBT testing system and method, which can achieve fast switching between static testing and dynamic testing, thereby effectively improving the efficiency and safety of IGBT testing.

[0026] Figure 1 An IGBT test system is shown according to an exemplary embodiment of the present disclosure. Figure 1 As shown, the IGBT test system may include: a signal transfer module 110, an IGBT test circuit 120, a drive module 130 and a controller 140; The signal switching module 110 and the driving module 130 are both connected to the IGBT test circuit 120 , and the signal switching module 110 , the IGBT test circuit 120 and the driving module 130 are all connected to the controller 140 .

[0027] It should be understood that IGBT is a semiconductor device that integrates the high input impedance characteristics of MOSFET and the low saturation voltage drop characteristics of BJT. It has the advantages of high efficiency, high-speed switching, low loss, etc. It can be widely used in DC motor drive, AC inverter, UPS power supply, wind power generation and solar power generation systems. Its core function is to control the on and off of current, thereby realizing the regulation and conversion of current, and then completing the conversion of electric energy.

[0028] It should be understood that in the converter, IGBT is responsible for the switch control task of regulating the current and needs to withstand the pressure of high voltage and high current. Therefore, the performance, working state and health of IGBT directly determine the overall efficiency of the converter. For example, when an IGBT fails, it may cause the output voltage of the converter to be unstable, the efficiency to be reduced, and even cause the entire system to shut down. For this reason, it is particularly important to detect the status of the IGBT.

[0029] It should also be understood that static testing is mainly to test the performance of IGBT in static working state (such as normal on / off state or standby state). Static testing can reflect the basic electrical characteristics of IGBT, such as switching threshold voltage, leakage current, withstand voltage, etc. The stability and accuracy of these parameters directly affect the normal operation of the converter. For example, if the static leakage current of IGBT increases during operation, it may cause power loss or device heating, and in severe cases, it may cause system failure. Therefore, static testing can identify possible hidden faults at an early stage and ensure that the equipment can operate in a suitable working state.

[0030] It should also be understood that dynamic testing is mainly to test the switching characteristics of IGBT, including switching speed, switching loss, short circuit, and overvoltage or overcurrent protection of the switch. Dynamic testing can reflect the voltage and current changes generated by IGBT during fast switching. This is crucial for optimizing the working mode of the converter, reducing switching loss, and improving system efficiency.

[0031] For example, according to actual conditions, a single-chip microcomputer can be used as a controller. The single-chip microcomputer has the characteristics of low cost, high integration, and strong programmability. It can provide flexible control strategies and fast real-time response. At the same time, with its low power consumption, anti-interference performance and rich interface support, it can realize complex data acquisition and processing logic.

[0032] Through the above technical scheme, the IGBT test system disclosed in the present invention may include a signal adapter module 110, an IGBT test circuit 120, a drive module 130 and a controller 140, wherein the signal adapter module 110 and the drive module 130 are both connected to the IGBT test circuit 120, and the signal adapter module 110, the IGBT test circuit 120 and the drive module 130 are all connected to the controller 140, so that integrated unified control can be achieved, and the target test object in the IGBT test circuit 120 can be quickly switched between dynamic and static test modes through the signal adapter module 110 and the drive module 130, thereby effectively improving the efficiency and safety of the IGBT test.

[0033] Figure 2 is a structural schematic diagram of an IGBT test circuit 120 according to an exemplary embodiment of the present disclosure. Figure 2 As shown, the IGBT test circuit 120 may include an IGBT module to be tested, and the IGBT module to be tested may include a first IGBT to be tested 11 and a second IGBT to be tested 12; The first IGBT 11 to be tested and the second IGBT 12 to be tested are connected in series to form a half-bridge arm circuit structure; The gate of the first IGBT 11 to be tested and the gate of the second IGBT 12 to be tested are both connected to the driving module 130 .

[0034] It should be understood that by connecting the first IGBT 11 (upper tube) and the second IGBT 12 (lower tube) to be tested in series to form a half-bridge arm circuit structure, the working state of the IGBT in actual application can be simulated, thereby improving the reliability and accuracy of the test results.

[0035] It should also be understood that the gate of the first IGBT 11 to be tested and the gate of the second IGBT 12 to be tested are both connected to the driving module 130, wherein the driving module 130 can accurately control the on and off of the IGBT through the driving circuit, ensuring that the IGBT can work as expected during the test process, and that the IGBTs in the converter usually need to work in coordination. The driving module 130 can simulate the control method in the actual circuit and provide accurate pulse signals during the dynamic switching characteristics test, thereby achieving precise control and comprehensive testing of the IGBT module to be tested.

[0036] Optionally, the IGBT test circuit 120 may include a capacitor 13 and an inductor 14; A first end of the capacitor 13 is connected to the collector of the first IGBT 11 to be tested, and a second end of the capacitor 13 is connected to the emitter of the second IGBT 12 to be tested; The inductor 14 is connected in series with the IGBT module to be tested.

[0037] It should be understood that capacitor 13 can play the role of energy caching and voltage smoothing, which is equivalent to simulating the DC bus capacitor in the actual converter. When performing dynamic testing of IGBT, it can be connected to the high-voltage DC capacitor to supply instantaneous energy. Inductor 14 is equivalent to simulating the load characteristics in the actual power electronic system, which can limit the current change rate and reduce the current mutation during the switching process. In this way, a test circuit close to the actual working conditions can be constructed to more comprehensively evaluate the performance of the IGBT and improve the engineering applicability of the test results.

[0038] Optionally, the IGBT test circuit 120 may include a first relay 15 , a second relay 16 , and a third relay 17 ; The control end of the first relay 15, the control end of the second relay 16 and the control end of the third relay 17 are all connected to the signal switching module 110; The first relay 15 is arranged on the branch where the capacitor 13 is located, the second relay 16 is arranged on the branch between the first IGBT 11 to be tested and the inductor 14 , and the third relay 17 is arranged on the branch between the second IGBT 12 to be tested and the inductor 14 .

[0039] It should be understood that the path connection mode of the test circuit can be adjusted by controlling the opening and closing states of the first relay 15, the second relay 16 and the third relay 17, so as to realize the rapid conversion of the static test and the dynamic test of the target test object in the IGBT module to be tested. And by uniformly controlling the three relays through the signal transfer module 110, the automatic switching of the test path can be realized, and the intelligence level of the test system can be improved.

[0040] It should be understood that if the high-voltage power supply and the capacitor are always connected and in parallel, this structure has a safety hazard. Once the IGBT is short-circuited due to breakdown, the energy of the capacitor cannot be released well, which can easily damage the equipment and make it difficult to perform the static withstand voltage test of the IGBT. By setting the first relay 15 on the branch where the capacitor 13 is located, the safety of the test process can be guaranteed and serious damage to the equipment can be avoided.

[0041] It should also be understood that the above relay setting can be used to switch the open and closed states for the target test object and the target test mode, ensuring independent testing of different IGBTs, avoiding mutual influence, and improving the accuracy of the test results. And by switching the open and closed states of the relay, the same circuit components can be reused for different tests, thereby simplifying the circuit design and reducing the equipment cost.

[0042] Specifically, when the target test type is a static test and the target test object is the first IGBT11 to be tested, the first relay 15 can be controlled to be in an open state, the second relay 16 can be controlled to be in an open state, and the third relay 17 can be controlled to be in a closed state through the signal conversion module 110; when the target test type is a static test and the target test object is the second IGBT12 to be tested, the first relay 15 can be controlled to be in an open state, the second relay 16 can be controlled to be in a closed state, and the third relay 17 can be controlled to be in an open state through the signal conversion module 110; when the target test type is a dynamic test and the target test object is the first IGBT11 to be tested, the first relay 15 can be controlled to be in a closed state, the second relay 16 can be controlled to be in an open state, and the third relay 17 can be controlled to be in a closed state; when the target test type is a dynamic test and the target test object is the second IGBT12 to be tested, the first relay 15 can be controlled to be in a closed state, the second relay 16 can be controlled to be in an open state, and the third relay 17 can be controlled to be in an open state.

[0043] For example, the signal adapter module can be used as a special circuit to achieve intelligent switching and precise control of the signal path in the test system through precise analog switches, digital logic and relay drive circuits. Its output end is connected to the control end of the relay, which can quickly and accurately manage signal routing, effectively isolate test channels, protect the devices under test, and improve the reliability and automation level of the test system.

[0044] For example, the first relay 15, the second relay 16 and the third relay 17 can all be high-voltage relays, which have the characteristics of high insulation strength, good arc resistance, and rapid switching transient response, and can achieve safe and reliable control of the IGBT test circuit.

[0045] Optionally, the IGBT test circuit 120 may include a power module; The positive electrode of the power module is connected to the collector of the first IGBT11 to be tested, and the negative electrode of the power module is connected to the emitter of the second IGBT12 to be tested; The control end of the power module is connected to the controller 140 .

[0046] It should be understood that the power module can provide a stable power supply for the IGBT test circuit to simulate the DC power supply environment in the actual inverter, and the power module control end is connected to the controller 140 to achieve precise control of the power output, thereby improving the reliability of the test results.

[0047] It should be understood that a relatively high DC voltage (e.g. 600V, 1200V, 1700V, etc.) is usually required in the static test of IGBT to simulate the voltage conditions that the IGBT is subjected to during operation. And the power module should be able to provide a stable and adjustable output voltage. Therefore, a high-voltage power module can be used to provide high-voltage voltage conditions consistent with the actual application scenarios of the IGBT, so that the test can truly restore the working state of the device in actual applications. Through the high-voltage power supply, the key parameters of the IGBT such as the static withstand voltage characteristics and dynamic switching characteristics can be accurately tested, and the reliability and limit performance of the device can be comprehensively evaluated.

[0048] Optionally, the IGBT test system may further include a communication module; The controller 140 sends the voltage information and current information of the IGBT module to be tested to the target host computer through the communication module, and receives the instruction information sent by the target host computer.

[0049] It should be understood that the communication module can realize two-way communication between the controller and the host computer, which not only improves the intelligence level of the test system, but also enhances the real-time and reliability of data acquisition, making the IGBT test process more efficient, accurate and reliable.

[0050] For example, the communication module is a communication module that can communicate through the RS232 communication protocol, thereby providing a stable and reliable data transmission channel for the IGBT test system, with strong anti-interference ability and wide compatibility. RS232, as a serial communication standard, can support point-to-point communication, realize accurate exchange of voltage information and current information between the controller and the host computer within a short distance, and ensure the reliability and real-time performance of data transmission.

[0051] Figure 3 The flowchart of an IGBT testing method according to an exemplary embodiment of the present disclosure is shown, which can be applied to the above-mentioned IGBT testing system. The method may include the following steps: Step S301 , the controller determines a target test object of the IGBT module to be tested in response to a target test type instruction sent by a target host computer, the target test type includes a static test and a dynamic test, and the target test object includes a first IGBT to be tested and a second IGBT to be tested.

[0052] Step S302: The controller controls the first relay, the second relay and the third relay in the IGBT test circuit to reach the corresponding target open and close states through the signal switching module according to the target test type and the target test object.

[0053] It should be understood that controlling the opening and closing states of the first, second and third relays in the IGBT test circuit through the signal conversion module can not only flexibly switch between different test modes, but also ensure the safety and reliability of the test circuit, significantly improving the adaptability and test efficiency of the IGBT test system.

[0054] Step S303, when the target opening and closing state is reached, the controller adjusts the output voltage of the power module according to a preset time interval and a preset step amount, and sends the collected current voltage value of the target test object to the target host computer according to the preset time interval.

[0055] It should be understood that by gradually adjusting the output voltage of the power module at preset time intervals and preset step sizes, the potential damage to the device caused by sudden and large voltage changes can be avoided, and the performance of the IGBT under different operating voltage conditions can be simulated, and the voltage changes of the test object can be monitored and recorded in real time. At the same time, the controller periodically transmits the collected current voltage value to the host computer, which not only ensures the continuity and accuracy of the test data, but also provides detailed and continuous technical parameters for subsequent data analysis and performance evaluation, thereby improving the reliability and safety of IGBT testing.

[0056] For example, the current voltage value can be collected through a voltage collection circuit, which can be composed of a precision voltage divider resistor, an isolation amplifier, and an analog-to-digital converter. The high-voltage signal in the test circuit is scaled by the voltage divider resistor, and then conditioned and amplified by the isolation amplifier. Finally, the analog voltage signal can be converted into a digital quantity by a high-precision analog-to-digital converter. The controller reads the digital quantity to obtain the current voltage value of the IGBT module.

[0057] For example, the preset time interval and the preset step size can be set according to actual conditions, and the embodiments of the present disclosure are not limited to this.

[0058] Step S304: the target host computer determines the test result of the target test object according to the output voltage and the current voltage value.

[0059] Through the above method, the IGBT test method can realize static and dynamic testing of the target IGBT to be tested, and can automatically switch the test mode and circuit configuration according to the host computer instruction. And adopt a progressive voltage adjustment strategy, through the preset time interval and step amount, to achieve accurate evaluation of the performance of IGBT under different working voltages, and transmit the collected voltage data to the host computer in real time, making the test process more intelligent, efficient and reliable, which can effectively improve the efficiency and safety of IGBT testing.

[0060] In a possible implementation, the controller controls the first relay, the second relay, and the third relay in the IGBT test circuit to reach the corresponding target open and close states through the signal switching module according to the target test type and the target test object, which may include: In the case where the target test type is a static test, the controller determines the target test object as a first IGBT to be tested, controls the first relay to be in an open state, the second relay to be in an open state, and the third relay to be in a closed state through the signal switching module, and in the case where the first IGBT to be tested passes the static test, determines the target test object as a second IGBT to be tested, controls the first relay to be in an open state, the second relay to be in a closed state, and the third relay to be in an open state through the signal switching module; When the target test type is a dynamic test, the controller determines the target test object as the first IGBT to be tested, and controls the first relay to be in a closed state, the second relay to be in an open state, and the third relay to be in a closed state through the signal conversion module. When the first IGBT to be tested passes the dynamic test, the controller determines the target test object as the second IGBT to be tested, and controls the first relay to be in a closed state, the second relay to be in a closed state, and the third relay to be in an open state through the signal conversion module.

[0061] It should be understood that this relay control method for performing static and dynamic tests on the target IGBT to be tested can accurately control the opening and closing states of the relay through the signal conversion module, thereby achieving rapid switching of the circuit path, ensuring the safety and accuracy of the test process, and by automatically switching the test path, it can reduce manual intervention, thereby improving test efficiency and system reliability.

[0062] In a possible implementation manner, the target host computer determines the test result of the target test object according to the output voltage and the current voltage value, which may include: The controller sends the current voltage value of the target test object collected at each preset time interval to the target host computer, and the target host computer determines whether the current voltage value is within the first preset range. If the target host computer determines that the current voltage value is within the preset voltage range, the controller controls the output voltage to increase according to the preset time interval and the preset step amount, and sends the current voltage value of the target test object collected to the target host computer according to the preset time interval until the output voltage reaches the preset voltage threshold; When the target test type is a static test and the output voltage reaches a preset voltage threshold, the controller sends the collected voltage value of the target test object within a preset time length to the target host computer, and the target host computer determines whether the voltage value within the preset time length is within a second preset range; If the voltage value within the preset time period is within the second preset range, the target host computer determines that the target test object passes the static test; If either the current voltage value is not within the first preset voltage range or the voltage value within the preset time is not within the second preset voltage range, the target host computer determines that the target test object has failed the static test and sends a current limiting protection instruction to the controller.

[0063] It should be understood that through the collaborative work of the controller and the host computer, the voltage can be accurately and controllably increased during the IGBT test. Specifically, the controller periodically transmits the current voltage value of the target test object to the host computer, and the host computer makes a real-time judgment on the voltage value to ensure that it is within the first preset range. And through the progressive voltage regulation strategy, the performance of the IGBT under different voltage conditions can be accurately evaluated, effectively avoiding the potential damage to the device caused by sudden and large voltage changes, thereby ensuring the safety and reliability of the test process.

[0064] It should be understood that the controller can send the current voltage value of the target test object collected at each preset time interval to the target host computer. If the target host computer determines that the current voltage value collected corresponding to a certain preset time interval is not within the first preset range, then combined with the current target test type, it can be determined that the target test object has not passed the static test or dynamic test, and the subsequent test steps are terminated and the current limiting protection mode is entered.

[0065] It should also be understood that during the IGBT static test process, when the current voltage value of the target test object collected at each preset time interval is within the first preset range and the output voltage reaches the preset voltage threshold, the controller can continuously transmit the voltage value of the target test object within the preset time length to the target host computer. If the target host computer determines that the voltage is not maintained within the second preset range within the preset time length, it is determined that the target test object has failed the static test. At this time, the subsequent static test steps will be terminated and the current limiting protection mode will be entered.

[0066] The above-mentioned determination mechanism can not only fully reflect the static working characteristics of the IGBT under test, but also effectively identify the potential defects of the device, such as voltage instability, abnormal leakage current, etc. If the target test object fails to meet the preset conditions, the host computer will immediately determine that it has failed the static test and send a current limiting protection instruction, thereby protecting the test equipment and the IGBT under test to the greatest extent, reflecting the safety and reliability of the test system.

[0067] For example, the preset voltage threshold, the first preset range, the second preset range and the preset duration can all be set according to actual conditions, and the embodiments of the present disclosure are not limited to this.

[0068] For example, before performing IGBT related tests, the IGBT voltage and current level data can be input into the host computer software in advance, and the high-voltage power supply can be controlled through the host computer software and communication with the microcontroller instructions, so that the high-voltage power supply can be increased to the corresponding voltage according to the preset voltage and current related parameters when performing IGBT testing, thereby improving the reliability of the test process.

[0069] In a possible implementation, the method may further include: When the target test type is a dynamic test and the output voltage reaches a preset voltage threshold, the controller controls the driving module to output a driving signal to the target test object, and sends the voltage waveform and current waveform of the target test object collected according to the driving signal to the target host computer, and the target host computer determines whether the voltage waveform and the current waveform have abnormal characteristics according to the preset waveform standard; If the voltage waveform and the current waveform do not have abnormal features, the target host computer determines that the target test object has passed the dynamic test; If any one of the following conditions is met: the current voltage value is not within the first preset voltage range, and the voltage waveform and / or current waveform has abnormal characteristics, the target host computer determines that the target test object has failed the dynamic test and sends a current limiting protection instruction to the controller.

[0070] It should be understood that during the IGBT dynamic test process, when the current voltage value of the target test object collected at each preset time interval is within the first preset range, and the output voltage reaches the preset voltage threshold, the controller can control the drive module to output a drive signal to the target test object, and collect the voltage waveform and current waveform according to the drive signal. The drive signal can be understood as a pulse signal, which has a specific frequency, duty cycle and amplitude, and can simulate the switching behavior of the IGBT in the actual working environment, thereby providing a more comprehensive and in-depth analysis mechanism for the dynamic performance evaluation of the IGBT. The target host computer can analyze whether there are abnormal characteristics of the voltage waveform and the current waveform according to the preset waveform judgment standard, such as waveform distortion, oscillation, burrs, etc., so as to determine whether the target test object passes the dynamic test. This test method based on waveform analysis can not only discover potential defects that may exist in the IGBT, but also provide a more objective and accurate technical basis for the quality control and screening of the device.

[0071] For example, the preset waveform standard can be evaluated from two dimensions, voltage and current, in combination with the device specifications. Specifically, key parameters such as the waveform rise time, fall time, maximum amplitude, peak current, and current change rate can be included. By identifying abnormal characteristics such as waveform distortion, spike mutation, asymmetry, and oscillation characteristics, and setting a corresponding deviation range as the judgment standard, the dynamic switching performance of the IGBT can be comprehensively and objectively evaluated to ensure that it meets the expected technical indicators and reliability requirements.

[0072] For example, during the dynamic test process, the voltage signal and current signal of the IGBT during operation can be captured by sensors such as voltage sensors and current transformers, and the voltage signal and current signal of the IGBT under test can be sampled in real time through an analog-to-digital converter. During the acquisition process, isolation amplifiers and signal conditioning circuits can be used to ensure signal accuracy. The collected digitized waveform data is transmitted from the controller to the target host computer. During the transmission process, data compression and verification mechanisms can be used to ensure the real-time, accuracy and integrity of the waveform information.

[0073] Figure 4 FIG. 1 is a flow chart of an IGBT static test method according to an exemplary embodiment of the present disclosure. Figure 4 As shown, the IGBT static test method may include the following steps: Step S401, IGBT static withstand voltage test starts.

[0074] Step S402: The host computer issues a static withstand voltage test instruction.

[0075] Step S403, the single chip microcomputer issues a static withstand voltage test instruction for the T1 tube.

[0076] Step S404, control relays S1 to be opened, S2 to be opened, and S3 to be closed.

[0077] Step S405, boosting the high voltage power supply according to a preset time interval, and collecting the voltage of the T1 tube.

[0078] Step S406, determining whether the T1 tube voltage collected at each preset time interval is within a preset range, if so, executing step S307, otherwise executing step S308.

[0079] Step S407, after the voltage boost is completed, determine whether the voltage of tube T1 can reach the set voltage value and maintain it for a certain period of time, if so, execute step S409, otherwise execute step S408.

[0080] Step S408: If the static withstand voltage test of tube T1 fails, the high voltage power supply current limiting protection is performed.

[0081] Step S409: The static withstand voltage test of the T1 tube passes.

[0082] Step S410, the single chip microcomputer issues a static withstand voltage test instruction for the T2 tube.

[0083] Step S411, control relay S1 to be opened, S2 to be closed, and S3 to be opened.

[0084] Step S412, boost the high voltage power supply according to the preset time interval and collect the T2 tube voltage. Step S413, determine whether the T2 tube voltage collected at each preset time interval is within the preset range, if so, execute step S414, otherwise execute step S415.

[0085] Step S414, after the voltage boost is completed, determine whether the voltage of tube T2 can reach the set voltage value and maintain it for a certain period of time, if so, execute step S416, otherwise execute step S415.

[0086] Step S415: if the static withstand voltage test of tube T2 fails, the high voltage power supply current limiting protection is performed.

[0087] Step S416: The static withstand voltage test of tube T2 passes.

[0088] Step S317, the IGBT static withstand voltage test is completed.

[0089] It should be understood that the T1 tube in the above steps corresponds to the aforementioned first IGBT to be tested, the T2 tube corresponds to the aforementioned second IGBT to be tested, and the single chip microcomputer corresponds to the aforementioned controller.

[0090] Figure 5 FIG. 1 is a flow chart of an IGBT dynamic testing method according to an exemplary embodiment of the present disclosure. Figure 5 As shown, the IGBT dynamic testing method may include the following steps: Step S501, IGBT dynamic switching characteristic test starts.

[0091] Step S502: The host computer issues a dynamic switch characteristic test instruction.

[0092] Step S503: the single chip microcomputer issues a T1 tube dynamic switch characteristic test instruction.

[0093] Step S504, control relay S1 to close, S2 to open and S3 to close.

[0094] Step S505, boosting the high voltage power supply according to a preset time interval, and collecting the voltage of the T1 tube.

[0095] Step S506, determining whether the T1 tube voltage collected at each preset time interval is within a preset range, if so, executing step S507, otherwise executing step S510.

[0096] Step S507, the T1 tube driving signal is enabled.

[0097] Step S508, collecting voltage and current waveforms.

[0098] Step S509, determining whether the waveforms of the voltage and current are normal, if so, executing step S511, otherwise executing step S510.

[0099] Step S510: The dynamic switch characteristic test of the T1 tube fails, and the high voltage power supply current limiting protection is performed.

[0100] Step S511: The dynamic switch characteristic test of tube T1 passes.

[0101] Step S512: the single chip microcomputer issues a T2 tube dynamic switch characteristic test instruction.

[0102] Step S513, control relays S1 to close, S2 to close and S3 to open.

[0103] Step S514, boost the high voltage power supply according to the preset time interval and collect the T1 tube voltage. Step S515, determine whether the T1 tube voltage collected at each preset time interval is within the preset range, if so, execute step S516, otherwise execute step S519.

[0104] Step S516, the T2 tube driving signal is enabled.

[0105] Step S517, collecting voltage and current waveforms.

[0106] Step S518, determining whether the waveforms of the voltage and current are normal, if so, executing step S520, otherwise executing step S519.

[0107] Step S519: The dynamic switch characteristic test of the T2 tube fails, and the high voltage power supply current limiting protection is performed.

[0108] Step S520: The dynamic switch characteristic test of tube T2 passes.

[0109] Step S521, the IGBT dynamic switching characteristic test is completed.

[0110] It should be understood that the T1 tube in the above steps corresponds to the aforementioned first IGBT to be tested, the T2 tube corresponds to the aforementioned second IGBT to be tested, and the single chip microcomputer corresponds to the aforementioned controller.

[0111] In summary, the IGBT testing system and method provided by the embodiments of the present invention comprehensively consider the combination of the static withstand voltage test of the IGBT and the dynamic switch test of the IGBT. By cooperating with the target host computer to issue instructions to the relays and power modules in the driving module and the test circuit, as well as the related dynamic voltage control strategy and current limiting protection settings, the static test and dynamic test switching of the target IGBT to be tested can be realized, which effectively saves the test equipment cost, improves the test efficiency, and ensures the safety of the test process.

[0112] The preferred embodiments of the present disclosure are described in detail above in conjunction with the accompanying drawings; however, the present disclosure is not limited to the specific details in the above embodiments. Within the technical concept of the present disclosure, a variety of simple modifications can be made to the technical solution of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

[0113] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.

[0114] In addition, various embodiments of the present disclosure may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the contents disclosed by the present disclosure.

Claims

1. An IGBT test system, characterized in that: The IGBT test system comprises: a signal switching module, an IGBT test circuit, a drive module and a controller; The signal switching module and the driving module are both connected to the IGBT test circuit, and the signal switching module, the IGBT test circuit and the driving module are all connected to the controller.

2. The IGBT test system according to claim 1, characterized in that: The IGBT test circuit includes an IGBT module to be tested, and the IGBT module to be tested includes a first IGBT to be tested and a second IGBT to be tested; The first IGBT to be tested and the second IGBT to be tested are connected in series to form a half-bridge arm circuit structure; The gate of the first IGBT to be tested and the gate of the second IGBT to be tested are both connected to the driving module.

3. The IGBT test system according to claim 2, characterized in that: The IGBT test circuit includes a capacitor and an inductor; The first end of the capacitor is connected to the collector of the first IGBT to be tested, and the second end of the capacitor is connected to the emitter of the second IGBT to be tested; The inductor is connected in series with the IGBT module to be tested.

4. The IGBT test system according to claim 3, characterized in that: The IGBT test circuit comprises a first relay, a second relay and a third relay; The control end of the first relay, the control end of the second relay and the control end of the third relay are all connected to the signal switching module; The first relay is arranged on the branch where the capacitor is located, the second relay is arranged on the branch between the first IGBT to be tested and the inductor, and the third relay is arranged on the branch between the second IGBT to be tested and the inductor.

5. The IGBT test system according to claim 2, characterized in that: The IGBT test circuit includes a power module; The positive electrode of the power module is connected to the collector of the first IGBT to be tested, and the negative electrode of the power module is connected to the emitter of the second IGBT to be tested; The control end of the power module is connected to the controller.

6. The IGBT test system according to claim 2, characterized in that: The IGBT test system also includes a communication module; The controller sends the voltage information and current information of the IGBT module to be tested to the target host computer through the communication module, and receives the instruction information sent by the target host computer.

7. An IGBT testing method, characterized in that: Applied to the IGBT test system according to any one of claims 1 to 6, the method comprising: The controller determines a target test object of the IGBT module to be tested in response to a target test type instruction sent by the target host computer, wherein the target test type includes a static test and a dynamic test, and the target test object includes a first IGBT to be tested and a second IGBT to be tested; The controller controls the first relay, the second relay and the third relay in the IGBT test circuit to reach the corresponding target open and close states through the signal switching module according to the target test type and the target test object; When the target open / close state is reached, the controller adjusts the output voltage of the power module according to a preset time interval and a preset step amount, and sends the collected current voltage value of the target test object to the target host computer according to the preset time interval; The target host computer determines a test result of the target test object according to the output voltage and the current voltage value.

8. The method according to claim 7, characterized in that The controller controls the first relay, the second relay, and the third relay in the IGBT test circuit to reach corresponding target open and close states through the signal switching module according to the target test type and the target test object, including: In the case where the target test type is a static test, the controller determines the target test object as the first IGBT to be tested, controls the first relay to be in an open state, the second relay to be in an open state, and the third relay to be in a closed state through the signal switching module, and in the case where the first IGBT to be tested passes the static test, determines the target test object as the second IGBT to be tested, controls the first relay to be in an open state, the second relay to be in a closed state, and the third relay to be in an open state through the signal switching module; When the target test type is a dynamic test, the controller determines the target test object as the first IGBT to be tested, and controls the first relay to be in a closed state, the second relay to be in an open state, and the third relay to be in a closed state through the signal conversion module. When the first IGBT to be tested passes the dynamic test, the target test object is determined to be the second IGBT to be tested, and the first relay is controlled to be in a closed state, the second relay to be in a closed state, and the third relay to be in an open state through the signal conversion module.

9. The method according to claim 8, characterized in that The target host computer determines the test result of the target test object according to the output voltage and the current voltage value, including: The controller sends the current voltage value of the target test object collected at each preset time interval to the target host computer, and the target host computer determines whether the current voltage value is within a first preset range. If the target host computer determines that the current voltage value is within the preset voltage range, the controller controls the output voltage to increase according to the preset time interval and the preset step amount, and sends the collected current voltage value of the target test object to the target host computer according to the preset time interval until the output voltage reaches a preset voltage threshold; When the target test type is a static test and the output voltage reaches a preset voltage threshold, the controller sends the collected voltage value of the target test object within a preset time length to the target host computer, and the target host computer determines whether the voltage value within the preset time length is within a second preset range; If the voltage value within the preset time period is within the second preset range, the target host computer determines that the target test object passes the static test; If either the current voltage value is not within the first preset voltage range or the voltage value within the preset time period is not within the second preset voltage range, the target host computer determines that the target test object has failed the static test and sends a current limiting protection instruction to the controller.

10. The method according to claim 9, characterized in that The method further comprises: When the target test type is a dynamic test and the output voltage reaches a preset voltage threshold, the controller controls the driving module to output a driving signal to the target test object, and sends the voltage waveform and current waveform of the target test object collected according to the driving signal to the target host computer, and the target host computer determines whether the voltage waveform and the current waveform have abnormal characteristics according to a preset waveform standard; If the voltage waveform and the current waveform do not have the abnormal feature, the target host computer determines that the target test object passes the dynamic test; If any one of the following conditions is met: the current voltage value is not within the first preset voltage range, and the voltage waveform and / or the current waveform has the abnormal characteristics, the target host computer determines that the target test object has failed the dynamic test and sends a current limiting protection instruction to the controller.

Images