Test platform and test method for IGBT dynamic test

Abstract

The invention relates to a test platform and a test method for an IGBT (Insulated Gate Bipolar Translator) dynamic test. The method belongs to the technical field of IGBT testing. The invention mainly provides an IGBT full-dynamic test platform. The device is mainly characterized in that a test platform composed of a control unit, a main loop unit, a frequency adjusting unit and a power cycle control unit is adopted; the tested units are two IGBTs provided with thermosensitive units; the IGBTs in the two paths of IGBTs are respectively arranged in a clamp platform with a cooling function; and respectively applying set working current and working frequency alternately output by a direct-current power supply to the two IGBTs, when the junction temperature of the IGBTs reaches a set upper limit, cutting off the working current of the IGBTs, cooling the IGBTs to enable the junction temperature of the IGBTs to reach a set lower limit, and completing the high-frequency power cycle test in cycles. The device has the characteristics that the operation is simple and convenient, and the working current, the working frequency and the heat dissipation condition of the IGBT can be autonomously set, and is mainly used for examining the working state of an IGBT product under different current, frequency and heat dissipation conditions under the simulated IGBT application working condition.

Description

Technical Field

[0001] This invention belongs to the field of IGBT testing technology, specifically relating to a test platform for dynamic testing of IGBTs. This test platform is used to simulate IGBT application conditions and to evaluate the working status of IGBT products under different current, frequency, and heat dissipation conditions. Background Technology

[0002] With the continuous expansion of IGBT product applications and the advancement of materials science and semiconductor technology, IGBT product research and development is also deepening. Currently, there is an urgent need to develop an IGBT fully dynamic testing platform. This platform needs to continuously output a specified current at a certain frequency to test the current-carrying capacity of the device under different operating conditions in various application fields, and to test the temperature rise of the IGBT element under different current and frequency conditions. Therefore, a fully dynamic current-carrying device for IGBTs needs to be fabricated.

[0003] Fully dynamic testing platforms are crucial for the verification of new technologies and the iterative upgrading of products. They enable manufacturers to respond quickly to market changes and launch higher-performance products.

[0004] Currently, there is no testing equipment for IGBT product applications, either domestically or internationally. The invention enables dynamic IGBT testing to be performed under low energy consumption conditions, based on the application requirements. Summary of the Invention

[0005] The purpose of this invention is to address the above-mentioned shortcomings by providing a dynamic test platform and test method that is easy to operate and allows for independent setting of the IGBT's operating current, operating frequency, and heat dissipation conditions.

[0006] The technical solution of the test platform of this invention is: an IGBT dynamic test platform, characterized by: comprising a control unit, a main circuit unit, a frequency adjustment unit, and a power cycle control unit; wherein, the control unit includes a touch screen, a PLC, and a power control unit; the main circuit unit consists of an input and voltage adjustment unit, a 12-pulse transformer, a rectification unit, a filtering unit, a current control unit, an absorption unit, a thermistor power supply, and a thermistor voltage sampling and display unit; the frequency adjustment unit includes a frequency generator and an IGBT triggering unit; the power cycle control unit includes a cooling system, an air circuit system, and a fixture platform.

[0007] The 12-pulse transformer in the technical solution of the test platform of this invention includes a three-phase input terminal and two independent three-phase output terminals; the input and voltage regulation are electrically connected to the three-phase input terminal of the 12-pulse transformer.

[0008] The rectifier unit in the technical solution of the test platform of the present invention consists of two independent rectifier units, whose input terminals are electrically connected to the two three-phase output terminals of the 12-pulse transformer, respectively.

[0009] The filtering unit in the technical solution of the test platform of the present invention is composed of a filtering capacitor and a smoothing reactor, and its input end is electrically connected to the output end of two independent rectifier units.

[0010] The current control in the technical solution of the test platform of this invention is composed of IGBTs connected in series. Its input terminal is electrically connected to one output terminal of the filter unit, and its output terminal is electrically connected to the other output terminal of the filter unit through the unit under test. The absorption unit is composed of RC and connected to both ends of the IGBT.

[0011] The thermal power supply and thermal voltage sampling and display described in the technical solution of the test platform of this invention consist of voltage sampling, analog-to-digital conversion, and a computer. The voltage sampling is connected to the analog-to-digital conversion, which converts the analog signal of the sampled voltage into a digital signal and displays it on the computer screen.

[0012] The fixture platform described in the technical solution of the test platform of this invention consists of a heat sink, a water circuit, an air circuit, and a switching valve; wherein, the heat sink and the water circuit constitute a cooling system; and the air circuit and the switching valve constitute an air circuit system. The cooling system and the air circuit system are connected in parallel. During the flow-through test, the air circuit system is closed; during the flow-off test, the air circuit system is opened to blow the cooling water in the heat sink out of the cooling system.

[0013] The technical solution of the test method of this invention is: a dynamic test method for IGBTs, used for power cycling tests of IGBTs under high-frequency conditions, characterized in that: the unit under test is two IGBTs connected in series, and both IGBTs are equipped with a thermistor unit for testing junction temperature; the two IGBTs are respectively mounted in a fixture platform with cooling function; the set operating current and operating frequency, alternately output by the control unit, the main circuit unit and the frequency adjustment unit, are applied to the two IGBTs respectively; when the junction temperature of one of the IGBTs reaches the set upper limit, the operating current of the IGBT in that line is cut off, and the IGBT in that line is cooled so that its junction temperature reaches the set lower limit; then the set operating current is applied again to make the junction temperature of the IGBT in that line rise; the process of the other IGBT reaching the set upper and lower limits is reversed, and the high-frequency power cycling test is completed by repeating the cycle.

[0014] The fixture platform in the technical solution of the test method of this invention consists of a heat sink, a water circuit, an air circuit, and a switching valve; wherein, the heat sink and the water circuit constitute a cooling system; the air circuit and the switching valve constitute an air circuit system; the cooling system and the air circuit system are connected in parallel, the air circuit system is closed during the flow test, and the air circuit system is opened during the flow interruption test to blow the cooling water in the heat sink out of the cooling system; the unit under test is a single module consisting of two IGBT devices connected in series or a multi-module consisting of several IGBT devices connected in parallel.

[0015] The single module consisting of two IGBT devices connected in series in the technical solution of the test method of this invention is a first module consisting of IGBT1 and IGBT2 connected in parallel. The C pin of IGBT1 is connected to the power supply +, and the E pin of IGBT2 is connected to the power supply -. The E pin of IGBT1 and the C pin of IGBT2 are connected to a common point. The multi-module includes a second module consisting of IGBT3 and IGBT4 connected in series and a third module consisting of IGBT5 and IGBT6 connected in series. The C pins of IGBT3 and IGBT5 are connected to the power supply +, and the E pins of IGBT4 and IGBT6 are connected to the power supply -.

[0016] This invention employs an IGBT dynamic test platform comprised of a control unit, a main circuit unit, a frequency adjustment unit, and a power cycle control unit. The control unit includes a touchscreen, a PLC, and a power control unit. The main circuit unit consists of input and voltage regulation, a 12-pulse transformer, a rectifier unit, a filter unit, current control, an absorption unit, a thermistor, and a thermistor voltage sampling and display unit. The frequency adjustment unit includes a frequency generator and an IGBT triggering unit. The power cycle control unit includes a cooling system, a pneumatic system, and a fixture platform. The unit under test consists of two IGBTs connected in series, each equipped with a test... A junction temperature thermistor unit is used. Two IGBTs are mounted in a fixture platform with cooling function. The set operating current and operating frequency output alternately from the control unit, main circuit unit and frequency adjustment unit are applied to the two IGBTs respectively. When the junction temperature of one IGBT reaches the set upper limit, the operating current of the IGBT in that line is cut off and the IGBT in that line is cooled so that its junction temperature reaches the set lower limit. Then the set operating current is applied again to make the junction temperature of the IGBT in that line rise. The process of the other IGBT reaching the set upper and lower limits is reversed. The high-frequency power cycle test is completed by repeating the cycle.

[0017] This invention features simple operation and allows for independent setting of IGBT operating current, operating frequency, and heat dissipation conditions. It is mainly used to evaluate the operating status of IGBT products under different current, frequency, and heat dissipation conditions in simulated IGBT application scenarios. Attached Figure Description

[0018] Figure 1This is a structural block diagram of the IGBT dynamic test platform of the present invention.

[0019] Figure 2 This is the circuit diagram of the control unit.

[0020] Figure 3 This is a schematic diagram of the power cycle control unit.

[0021] Figure 4 This is a circuit diagram with an added frequency adjustment unit.

[0022] Figure 5 This is the main circuit diagram of the IGBT dynamic test platform of the present invention.

[0023] Figure 6 This is a structural diagram (module working mode) of the IGBT dynamic test platform of the present invention, showing the test unit.

[0024] Figure 7 This is a structural diagram of the IGBT dynamic test platform of the present invention (multi-module working mode).

[0025] Figure 8 This is a waveform diagram of the frequency adjustment drive of the IGBT dynamic test platform of the present invention.

[0026] Figure 9 This is a block diagram of the fixture structure for the IGBT dynamic testing platform of the present invention.

[0027] In the diagram: 1-Control unit; 11-Touch screen; 12-PLC; 13-Power control unit; 2-Main circuit unit; 21-Input and voltage regulation; 22-Pulse transformer; 23-Rectifier unit; 24-Filter unit; 25-Current control; 26-Absorption unit; 27-Measured unit; 28-Thermistor power supply; 29-Thermistor voltage sampling and display; 3-Frequency adjustment unit; 31-Frequency generator; 32-IGBT trigger unit; 4-Power cycle control unit; 41-Cooling system; 42-Air circuit system; 43-Clamping platform; 5-First module; 6-Second module; 7-Third module; 8-Thermistor unit; 9-Clamping; 10-Water valve. Detailed Implementation

[0028] The embodiments of the present invention will now be described in full with reference to the accompanying drawings. Obviously, the described embodiments are merely a part of the embodiments of the present invention, and not all of them. Any other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0029] The following examples illustrate the implementation of the present invention.

[0030] like Figures 1 to 9 As shown, an embodiment of the present invention for an IGBT dynamic test platform consists of a control unit 1, a main circuit unit 2, a frequency adjustment unit 3, and a power cycle control unit 4.

[0031] The control unit 1 includes a touch screen 11, a PLC 12, and a power control unit 13. The touch screen 11 is connected to the communication port of the PLC 12 via a communication cable, and each input / output port of the PLC 12 is connected to the power control unit 13.

[0032] The main circuit unit 2 consists of an input and voltage regulator 21, a 12-pulse transformer 22, a rectifier unit 23, a filter unit 24, a current control 25, an absorption unit 26, a thermistor 28, and a thermistor voltage sampling and display 29. The 12-pulse transformer 22 includes one three-phase input terminal and two independent three-phase output terminals. The input and voltage regulator 21 is electrically connected to the three-phase input terminal of the 12-pulse transformer 22. The rectifier unit 23 consists of two independent rectifier units, whose input terminals are electrically connected to the two three-phase output terminals of the 12-pulse transformer 22, respectively. The filter unit 24 consists of a filter capacitor and a smoothing reactor, and its input terminal is electrically connected to the output terminals of the two independent rectifier units. The current control 25 consists of series-connected IGBTs, and its input terminal is electrically connected to one output terminal of the filter unit 24. Its output terminal is electrically connected to the other output terminal of the filter unit 24 via the measured unit 27. The absorption unit 26 is composed of an RC circuit and connected across the IGBTs. The thermal power supply 28 and the thermal voltage sampling and display 29 consist of a voltage sampling unit, an analog-to-digital converter, and a computer. The voltage sampling unit is connected to the analog-to-digital converter, which converts the analog signal of the sampled voltage into a digital signal and displays it on the computer screen. The DC output section does not require a high-frequency power input; a standard 12-pulse rectifier circuit can output a stable high-frequency square wave current.

[0033] The frequency adjustment unit 3 includes a frequency generator 31 and an IGBT trigger unit 32. The frequency adjustment unit 3 receives frequency control signals from the PLC 12 and sends these signals to its internal IC. The IC performs logic calculations and outputs pulse signals of the corresponding frequency, which are applied to the gate of the control port of the device under test. The frequency adjustment unit 3 outputs two sets of drive signals with opposite polarities, and these two sets of signals have a 3µs superposition synchronization period to ensure that the main circuit system does not experience current interruption.

[0034] The power cycle control unit 4 includes a cooling system 41, an air circuit system 42, and a fixture platform 43. The fixture platform 43 consists of a heat sink, water circuit, air circuit, and switching valve; wherein, the heat sink and water circuit constitute the cooling system 41, and the air circuit and switching valve constitute the air circuit system 42. All of these are conventional technologies.

[0035] The unit under test 27 consists of two IGBTs, which can alternately conduct in both single-module and multi-module parallel operation modes to generate a high-frequency current with a set output frequency on the device under test. A single module, such as... Figure 5 As shown, the first module 5 consists of two IGBT devices connected in series. The collector (C) pin of IGBT1 is connected to the power supply +, and the emitter (E) pin of IGBT2 is connected to the power supply -. The emitter pin of IGBT1 and the collector pin of IGBT2 are connected to a common point. Multiple modules can be connected in parallel as follows... Figure 6 As shown, the second module 5 and the third module 6 are composed of four IGBT devices connected in series and parallel. The second module 5 contains IGBT3 and IGBT4 devices, and the third module 6 contains IGBT5 and IGBT6 devices. The C pin of IGBT3 and IGBT5 devices is connected to the power supply +, and the E pin of IGBT4 and IGBT6 devices is connected to the power supply -.

[0036] This invention discloses a test method for dynamic testing of IGBTs, specifically for power cycling tests of IGBTs under high-frequency conditions. The method includes the following steps: The test unit 27 consists of two IGBTs connected in series, each equipped with a thermistor 8 for measuring junction temperature; the two IGBTs are respectively mounted in a fixture platform 43 with cooling function; the test current and test frequency (0-50kHz) are set according to the touch screen, and relevant control signals are sent to each control node of the main circuit via PLC, thereby generating a constant DC power supply and two sets of high-frequency square wave currents with opposite polarities, applied to the two IGBTs respectively, causing the two IGBTs to alternately conduct and withstand the high-frequency current. When the junction temperature of one IGBT reaches the set upper limit, the operating current of that IGBT is cut off, and the IGBT is cooled to bring its junction temperature down to the set lower limit. Then, the set operating current is applied again to raise the junction temperature of that IGBT. The process of the other IGBT reaching the set upper and lower limits is reversed, and this cycle is repeated to complete the high-frequency power cycling test.

[0037] When the unit under test 27 is the first module 5, such as Figure 5 As shown. When the unit under test 27 is the second module 6 and the third module 7, as... Figure 6 As shown.

[0038] In the application of IGBT dynamic test platform, the device can be set to test under different operating conditions, the on and off of IGBT can be controlled, and the overload test of the product can be completed.

[0039] The IGBT dynamic testing platform controls the main circuit closure via control unit 1, and sets the test current and test frequency via touch screen 11. Relevant control signals are sent to each control node of the main circuit via PLC, thereby generating a constant DC power supply.

[0040] The IGBT dynamic test platform can perform power cycling tests at high frequencies. The thermal curve of the device under test (DUT) is measured by the thermistor 8 and the data is input to the computer control system. After the control unit 1 sets the operating current and frequency, the equipment automatically starts. The fixture platform 43 enters the heating mode, applying a high-frequency current to the DUT. Simultaneously, the air circuit system 42 is activated to blow water from the fixture platform 43 into the heat dissipation cavity, and the cavity heat dissipation circuit water valve 10 is closed. The high-frequency current causes the junction temperature of the DUT to rise rapidly. The thermistor 8 monitors the junction temperature, and once the junction temperature reaches the set value, the main current is cut off. The system automatically activates the heat dissipation mode, opening the cavity heat dissipation circuit water valve 10, allowing circulating water to flow into the fixture cavity, causing the junction temperature of the DUT to drop sharply. Once the junction temperature reaches the set lower limit, the equipment automatically switches back to the heating mode, and the high-frequency power cycling test is completed repeatedly.

[0041] The IGBT full dynamic testing platform has broad application prospects and can promote technological innovation and product upgrades.

[0042] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Therefore, any modifications, equivalent substitutions, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. An IGBT dynamic testing platform, characterized by: It consists of a control unit (1), a main circuit unit (2), a frequency adjustment unit (3), and a power circulation control unit (4); wherein, the control unit (1) includes a touch screen (11), a PLC (12), and a power control unit (13); the main circuit unit (2) consists of an input and voltage regulation (21), a 12-pulse transformer (22), a rectifier unit (23), a filter unit (24), a current control (25), an absorption unit (26), a thermistor (28), and a thermistor voltage sampling and display (29); the frequency adjustment unit (3) includes a frequency generator (31) and an IGBT trigger unit (32); the power circulation control unit (4) includes a cooling system (41), an air circuit system (42), and a fixture platform (43).

2. The IGBT dynamic test platform according to claim 1, characterized in that: The 12-pulse transformer (22) includes a three-phase input terminal and two independent three-phase output terminals; the input and voltage regulator (21) is electrically connected to the three-phase input terminal of the 12-pulse transformer (22).

3. The IGBT dynamic test platform according to claim 2, characterized in that: The rectifier unit (23) consists of two independent rectifier units, whose input terminals are electrically connected to the two three-phase output terminals of the 12-pulse transformer (22).

4. The IGBT dynamic test platform according to claim 3, characterized in that: The filter unit (24) consists of a filter capacitor and a smoothing reactor, and its input terminal is electrically connected to the output terminals of two independent rectifier units.

5. The IGBT dynamic test platform according to claim 4, characterized in that: The current control (25) is composed of IGBTs connected in series. Its input terminal is electrically connected to one output terminal of the filter unit (24), and its output terminal is electrically connected to the other output terminal of the filter unit (24) via the unit under test (27). The absorption unit (26) is composed of RC and connected to both ends of the IGBT.

6. The dynamic testing platform for IGBTs according to claim 5, characterized in that: The thermal power supply (28) and thermal voltage sampling and display (29) consist of voltage sampling, analog-to-digital conversion, and computer. The voltage sampling is connected to the analog-to-digital conversion, which converts the analog signal of the sampled voltage into a digital signal and displays it on the computer screen.

7. An IGBT dynamic testing platform according to any one of claims 1-6, characterized in that: The fixture platform (43) consists of a heat sink, a water circuit, an air circuit, and a switch valve; the heat sink and the water circuit constitute a cooling system (41); the air circuit and the switch valve constitute an air circuit system (42); the cooling system (41) and the air circuit system (42) are connected in parallel. During the flow test, the air circuit system is closed, and during the flow interruption test, the air circuit system is opened to blow the cooling water in the heat sink out of the cooling system (41).

8. An IGBT dynamic testing method using the IGBT dynamic test platform according to any one of claims 1-6, for power cycle testing of IGBTs under high-frequency conditions, characterized in that: The unit under test (27) consists of two IGBTs connected in series. Both IGBTs are equipped with a thermistor (8) for testing junction temperature. The two IGBTs are respectively mounted in a fixture platform (43) with cooling function. The set operating current and operating frequency, which are alternately output by the control unit (1), the main circuit unit (2) and the frequency adjustment unit (3), are applied to the two IGBTs. When the junction temperature of one of the IGBTs reaches the set upper limit, the operating current of the IGBT in that line is cut off and the IGBT in that line is cooled so that its junction temperature reaches the set lower limit. Then the set operating current is applied again to make the junction temperature of the IGBT in that line rise. The process of the junction temperature of the other IGBT reaching the set upper and lower limits is reversed. The high-frequency power cycle test is completed by repeating the cycle.

9. The IGBT dynamic testing method according to claim 8, characterized in that: The fixture platform (43) consists of a heat sink, a water circuit, an air circuit, and a switching valve; wherein the heat sink and the water circuit constitute a cooling system (41); the air circuit and the switching valve constitute an air circuit system (42); the unit under test (27) is a single module consisting of two IGBT devices connected in series or a multi-module consisting of several single modules consisting of two IGBT devices connected in series connected in parallel.

10. The IGBT dynamic testing method according to claim 9, characterized in that: The single module consisting of two IGBT devices connected in series is the first module (5) consisting of IGBT1 and IGBT2 connected in parallel. The C pin of IGBT1 is connected to the power supply +, and the E pin of IGBT2 is connected to the power supply -. The E pin of IGBT1 and the C pin of IGBT2 are connected to a common point. The multi-module includes the second module (6) consisting of IGBT3 and IGBT4 connected in series and the third module (7) consisting of IGBT55 and IGBT6 connected in series. The C pins of IGBT3 and IGBT5 are connected to the power supply +, and the E pins of IGBT4 and IGBT6 are connected to the power supply.

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