Coaxial switching circuit
By designing a coaxial switching circuit for dynamic characteristic testing of IGBT modules, the problems of expensive imported coaxial relays and long procurement cycle are solved, and the effect of reducing the cost of testing equipment and improving the testing efficiency is achieved.
Patent Information
- Application Number
- CN202420699581.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-07
- Publication Date
- 2025-03-04
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
Imported coaxial relays are expensive and have long procurement cycles, resulting in high cost, long manufacturing cycles, and difficult after-sales maintenance.
Design a coaxial switching circuit, including common mode inductors, resistors, capacitors and relays, to replace traditional coaxial relays and support for dynamic characteristics testing of IGBT modules.
Through the use of coaxial switching circuits, the volume and cost of the test equipment are reduced, the manufacturing cycle is shortened, the testing efficiency and system flexibility are improved, and the maintenance problems of traditional coaxial relays are solved.
Smart Images
Figure CN222561672U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of IGBT module dynamic characteristic testing and relates to a coaxial switching circuit. Background Art
[0002] With the development of power electronics technology and the improvement of semiconductor technology, the research on the characteristics of semiconductor devices in the field of power electronics is becoming more and more important. IGBT modules are newcomers in the semiconductor field. Their characteristics research includes static characteristics research and dynamic characteristics research. Static characteristics can often be obtained from datasheets, while dynamic characteristics need to be measured manually.
[0003] In the current national standards and IEC (International Electrotechnical Commission) standards, the measurement of dynamic characteristics is based on double pulse testing, which reflects the dynamic characteristics by measuring the voltage Vce and current Ic waveforms during the dynamic process.
[0004] With the development of the internal integration process of IGBT modules, the number of module chip units integrated inside has gradually increased, which has brought about a greater demand for voltage and current detection channels. Commonly used oscilloscopes are four-channel detection devices. The one-to-one detection of a single channel limits the number of internal units of the IGBT module that can be tested simultaneously by the test equipment; therefore, the total number of control detection channels determines the number of oscilloscopes for detecting signal processing instruments, thereby controlling the size and cost of the detection equipment; at the same time, imported coaxial relays are expensive, have a long procurement cycle, and are difficult to maintain after sales. Utility Model Content
[0005] The utility model is used to solve the problems of high price and long purchase cycle of imported coaxial relays.
[0006] The utility model solves the above technical problems through the following technical solutions:
[0007] A coaxial switching circuit comprises: a common mode inductor L2, a resistor R1, a capacitor C1, and a relay (14), wherein the common mode inductor L2 # Terminal grounding, common mode inductor L2 of 2 # The terminal is used as the IN terminal of the coaxial switching circuit, and the two parallel ends of the resistor R1 and the capacitor C1 are connected in parallel to the 3 ends of the common mode inductor L2. # Terminals and 4 # Terminal connections, relay (14) 1 # Terminal and common mode inductor L2 3 # Terminal connections, relay (14) 8 # Terminal and common mode inductor L2 of 4 #Terminal connections, relay (14) 5 # The terminal is used as the NC terminal of the coaxial switching circuit, and the 6 # The terminal is used as the OUT terminal of the coaxial switching circuit, the 7 # The terminal serves as the coaxial switching circuit NO terminal.
[0008] Furthermore, the model of the relay (14) is G6K-2F-RF.
[0009] Furthermore, the coaxial switching circuit further comprises: a resistor R2, a light emitting diode D1, one end of the resistor R2 and a 3-way common mode inductor L2. # The other end of the resistor R2 is connected to the anode of the light-emitting diode D1, and the cathode of the light-emitting diode D1 is connected to the 4 terminals of the common-mode inductor L2. # Terminal connections.
[0010] An IGBT module dynamic characteristics test system using the coaxial switching circuit comprises: a DC power supply U DC , bus capacitor C, inductor L1, 6 test probes T1-T6, 5 switches K1-K5, oscilloscope (10); the IGBT modules DUT1-DUT6 to be tested form a three-phase H-bridge circuit; after switches K1 and K2 are connected in series, the non-series end of switch K1 is connected to a DC power supply U DC The positive pole of switch K2 is connected to the DC power supply U DC The negative pole of the bus capacitor C is connected in parallel with the DC power supply U DC The positive and negative ends of the three-phase H-bridge circuit are connected; one end of the inductor L1 is connected to the common point of the switches K1 and K2 in series, one end of the switches K3, K4 and K5 are connected together and then connected to the other end of the inductor L1, the other end of the switch K3 is connected to the midpoint of the first bridge arm, the other end of the switch K4 is connected to the midpoint of the second bridge arm, and the other end of the switch K5 is connected to the midpoint of the third bridge arm; the test probes T1, T3 and T5 are respectively installed in the first bridge arm, the second bridge arm and the upper half of the third bridge arm of the three-phase H-bridge circuit, and the test probes T2, T4 and T6 are respectively installed in the first bridge arm, the second bridge arm and the upper half of the third bridge arm of the three-phase H-bridge circuit. The first bridge arm, the second bridge arm, and the lower half bridge arm of the third bridge arm; the output ends of the test probes T1, T3, and T5 are respectively connected to the NC terminals of the three coaxial switching circuits; the output ends of the test probes T2, T4, and T6 are respectively connected to the N0 terminals of the three coaxial switching circuits; the output ends of the test probes T1, T3, and T5 are respectively connected to the NC terminals of the three coaxial switching circuits; the OUT terminals of the three coaxial switching circuits are respectively connected to the first, second, and third measurement channels of the oscilloscope (10); and the IN terminals of the coaxial switching circuits input control signals.
[0011] The advantages of the utility model are:
[0012] 1) The utility model adopts a coaxial switching circuit to replace the coaxial relay, which solves the problems of expensive imported coaxial relays, long procurement cycle and difficult after-sales maintenance, and achieves the effect of import substitution, shortening the manufacturing cycle and greatly reducing costs;
[0013] 2) The test system of the utility model switches the coaxial switching circuit so that one channel of the oscilloscope can test two IGBT modules under test, thereby reducing the number of oscilloscopes by half, greatly reducing the volume and cost of the test equipment;
[0014] 3) The test system of the utility model can test the IGBT modules of the first bridge arm, the second bridge arm and the third bridge arm at the same time, and can also test the IGBT modules of one or two bridge arms separately, which improves the system integration and test efficiency while also having flexibility;
[0015] 4) The IGBT modules under test in the first bridge arm, the second bridge arm and the third bridge arm of the test system of the utility model are independent of each other. When a certain IGBT module under test is damaged, it will not affect the test of other IGBT modules under test. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 It is a circuit principle diagram of the coaxial switching circuit of the embodiment of the utility model;
[0017] Figure 2 This is a circuit schematic diagram of an IGBT module dynamic characteristics test system according to an embodiment of the utility model;
[0018] Figure 3 It is a circuit schematic diagram of the first bridge arm of the IGBT module dynamic characteristics test system according to an embodiment of the utility model. DETAILED DESCRIPTION
[0019] In order to make the purpose, technical solution and advantages of the embodiments of the utility model clearer, the technical solution in the embodiments of the utility model will be clearly and completely described below in combination with the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.
[0020] The technical solution of the utility model is further described below in conjunction with the accompanying drawings and specific embodiments of the specification:
[0021] Embodiment 1
[0022] like Figure 1 As shown, a coaxial switching circuit includes: a common mode inductor L2, a resistor R1, a resistor R2, a capacitor C1, a light emitting diode D1, and a relay 14, wherein the model of the relay 14 is G6K-2F-RF; 1 of the common mode inductor L2 # Terminal grounding, common mode inductor L2 of 2 # The terminal is used as the IN terminal of the coaxial switching circuit, and the two parallel ends of the resistor R1 and the capacitor C1 are connected in parallel to the 3 ends of the common mode inductor L2. # Terminals and 4 # The terminals are connected, one end of the resistor R2 is connected to the 3 # The other end of the resistor R2 is connected to the anode of the light-emitting diode D1, and the cathode of the light-emitting diode D1 is connected to the 4 terminals of the common-mode inductor L2. # Terminal connection, relay 14 1 # Terminal and common mode inductor L2 3 # Terminal connection, relay 14 to 8 # Terminal and common mode inductor L2 of 4 # Terminal connection, relay 14 to 5 # Terminal as coaxial switching circuit NC terminal, relay 14 6 # The terminal is used as the OUT terminal of the coaxial switching circuit, and the 7 # The terminal serves as the coaxial switching circuit NO terminal.
[0023] Working principle of the coaxial switching circuit: The control signal is input from the NO terminal, and after the common mode inductor L2 suppresses the noise and the filter circuit composed of the resistor R1 and the capacitor C1 filters the noise, the output of the control relay 14 switches between the NO terminal-OUT terminal branch and the NC terminal-OUT terminal branch; when the coil KA of the relay 14 is energized, the light emitting diode D1 lights up, and the contact KC of the relay 14 is 5 # Terminals and 6 # The terminal is closed, and the NC terminal-OUT terminal branch is connected; when the coil KA of the relay 14 loses power, the light-emitting diode D1 is extinguished, and the contact KC of the relay 14 is 7 # Terminals and 6 # The terminal is closed, and the NO terminal-OUT terminal branch is connected.
[0024] like Figure 2 As shown, an IGBT module dynamic characteristics test system includes: a DC power supply U DC, bus capacitor C, inductor L1, 6 test probes T1-T6, 5 switches K1-K5, oscilloscope 10, first coaxial switching circuit 11, second coaxial switching circuit 12, third coaxial switching circuit 13, and 6 IGBT modules DUT1-DUT6 under test.
[0025] The six IGBT modules DUT1 to DUT6 under test form a three-phase H-bridge circuit, wherein the IGBT modules DUT1 and DUT2 under test are connected in series to form the first bridge arm, the IGBT modules DUT3 and DUT4 under test are connected in series to form the second bridge arm, and the IGBT modules DUT5 and DUT6 under test are connected in series to form the third bridge arm; after the switches K1 and K2 are connected in series, the non-series end of the switch K1 is connected to the DC power supply U DC The positive pole of switch K2 is connected to the DC power supply U DC The negative pole of the bus capacitor C is connected in parallel with the DC power supply U DCThe positive and negative ends of the inductor L1; one end of the inductor L1 is connected to the common point of the switches K1 and K2 in series, one end of the switches K3, K4 and K5 are connected together and then connected to the other end of the inductor L1, the other end of the switch K3 is connected to the midpoint of the first bridge arm, the other end of the switch K4 is connected to the midpoint of the second bridge arm, and the other end of the switch K5 is connected to the midpoint of the third bridge arm; the test probes T1, T3 and T5 are respectively installed in the upper half of the first bridge arm, the second bridge arm and the third bridge arm, and are respectively used to test the current and voltage of the IGBT module DUT1, the IGBT module DUT3 and the IGBT module DUT5 under test; the test probes T2, T4 and T6 are respectively installed in the lower half of the first bridge arm, the second bridge arm and the third bridge arm, and are respectively used to test the current and voltage of the IGBT module DUT2, the IGBT module DUT4 and the IGBT module DUT6 under test; the test probes T1, T3 and T5 The output ends are respectively connected to the NC terminals of the first coaxial switching circuit 11, the second coaxial switching circuit 12, and the third coaxial switching circuit 13; the output ends of the test probes T2, T4, and T6 are respectively connected to the N0 terminals of the first coaxial switching circuit 11, the second coaxial switching circuit 12, and the third coaxial switching circuit 13; the output ends of the test probes T1, T3, and T5 are respectively connected to the NC terminals of the first coaxial switching circuit 11, the second coaxial switching circuit 12, and the third coaxial switching circuit 13; the OUT terminals of the first coaxial switching circuit 11, the second coaxial switching circuit 12, and the third coaxial switching circuit 13 are respectively connected to the first measurement channel, the second measurement channel, and the third measurement channel of the oscilloscope 10; the IN terminals of the first coaxial switching circuit 11, the second coaxial switching circuit 12, and the third coaxial switching circuit 13 are used to input control signals; the first coaxial switching circuit 11, the second coaxial switching circuit 12, and the third coaxial switching circuit 13 have the same structure.
[0026] The utility model adopts the first coaxial switching circuit 11, the second coaxial switching circuit 12, and the third coaxial switching circuit 13 to replace the coaxial relay, which solves the problems of expensive imported coaxial relays, long procurement cycle, and difficult after-sales maintenance, and achieves the effect of import substitution, shortening the manufacturing cycle and greatly reducing costs.
[0027] like Figure 3 As shown, the working principle of the IGBT module dynamic characteristics test system of the embodiment of the utility model is introduced by taking the first bridge arm as an example.
[0028] 1) Measure the IGBT module under test in the upper half of the first bridge arm:
[0029] Switches K2 and K3 are closed, and gate voltage is applied to the IGBT module DUT1 to turn it on, and the IGBT module DUT2 to turn it off; the current flows from the DC power supply U DC The positive electrode is connected to the DC power supply U through the test probe T1, the IGBT module DUT1, the switch K3, the inductor L1, and the switch K2. DC The negative pole forms a closed loop, and the test probe T1 transmits the measured voltage and current data to the NC terminal of the first coaxial switching circuit 11; at the same time, the control signal of the first coaxial switching circuit 11 controls the NC terminal-OUT terminal branch to be connected, thereby transmitting the voltage and current data measured by the test probe T1 to the oscilloscope 10 for reading.
[0030] 2) Measure the IGBT module under test in the lower half of the first bridge arm:
[0031] Switches K1 and K3 are closed, and gate voltage is applied to the IGBT module DUT2 to turn it on, and the IGBT module DUT1 is turned off; the current flows from the DC power supply U DC The positive electrode is connected to the DC power supply U through switch K1, inductor L1, switch K3, IGBT module DUT2, and test probe T2. DC The negative pole forms a closed loop, and the test probe T2 transmits the measured voltage and current data to the NO terminal of the first coaxial switching circuit 11; at the same time, the control signal of the first coaxial switching circuit 11 controls the NO terminal-OUT terminal branch to be connected, thereby transmitting the voltage and current data measured by the test probe T2 to the oscilloscope 10 for reading.
[0032] The principle of measuring the IGBT modules under test in the second bridge arm and the third bridge arm is the same as the principle of measuring the IGBT module under test in the first bridge arm, and will not be described in detail here.
[0033] The IGBT module dynamic characteristics test system of the embodiment of the utility model switches the coaxial switching circuit so that one channel of the oscilloscope 10 can test two IGBT modules under test, thereby reducing the number of oscilloscopes 10 by half, greatly reducing the size and cost of the detection equipment.
[0034] The IGBT module dynamic characteristics test system of the utility model embodiment can test the IGBT modules under test of the first bridge arm, the second bridge arm, and the third bridge arm at the same time, and can also test the IGBT modules under test of one or two bridge arms separately, thereby improving the system integration and test efficiency while also having flexibility.
[0035] The IGBT modules under test of the first bridge arm, the second bridge arm and the third bridge arm of the embodiment of the utility model are independent of each other. When a certain IGBT module under test is damaged, it will not affect the test of other IGBT modules under test.
[0036] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims
1. A coaxial switching circuit, characterized in that: include: Common mode inductor L2, resistor R1, capacitor C1, relay (14), the common mode inductor L2 of 1 # Terminal grounding, common mode inductor L2 of 2 # The terminal is used as the IN terminal of the coaxial switching circuit, and the two parallel ends of the resistor R1 and the capacitor C1 are connected in parallel to the 3 ends of the common mode inductor L2. # Terminals and 4 # Terminal connections, relay (14) 1 # Terminal and common mode inductor L2 3 # Terminal connections, relay (14) 8 # Terminal and common mode inductor L2 of 4 # Terminal connections, relay (14) 5 # The terminal is used as the NC terminal of the coaxial switching circuit, and the 6 # The terminal is used as the OUT terminal of the coaxial switching circuit, the 7 # The terminal serves as the coaxial switching circuit NO terminal.
2. The coaxial switching circuit according to claim 1, characterized in that: The model of the relay (14) is G6K-2F-RF.
3. The coaxial switching circuit according to claim 1, characterized in that: The coaxial switching circuit further includes: a resistor R2, a light emitting diode D1, one end of the resistor R2 and a 3-way common mode inductor L2. # The other end of the resistor R2 is connected to the anode of the light-emitting diode D1, and the cathode of the light-emitting diode D1 is connected to the 4 terminals of the common-mode inductor L2. # Terminal connections.