An IGBT bus circuit with adjustable inductance of converter loop

Abstract

The utility model relates to the field of power electronic test technology, concretely relates to a kind of IGBT bus circuit of adjustable commutation loop stray inductance, including bus capacitor C, the bus capacitor C is shunt in the two ends of DC power supply;Adjustable commutation loop stray inductance L1, the first end of the adjustable commutation loop stray inductance L1 is connected with the first end of the bus capacitor C;First IGBT device IGBT 1, the collector C1 of the first IGBT device IGBT 1 is connected with the second end of the adjustable commutation loop stray inductance L1;Host computer PC, the host computer PC is connected with the adjustable commutation loop stray inductance L1, for issuing adjustment instruction to the adjustable commutation loop stray inductance L1.The utility model introduces adjustable commutation loop stray inductance L1 and host computer PC control framework, realizes the flexible adjustment of commutation loop stray in IGBT module test platform, effectively solves the problem such as poor universality, high cost caused by custom bus structure in traditional test method.

Description

Technical Field

[0001] This utility model relates to the field of power electronics testing technology, specifically to an IGBT bus circuit with adjustable commutation circuit inductance. Background Technology

[0002] Power semiconductor devices, especially insulated-gate bipolar transistors (IGBTs), have become core components in modern energy conversion fields such as new energy vehicle drive systems, photovoltaic inverters, and wind power converters due to their superior performance. When designing and developing IGBT modules, accurate testing of their dynamic switching characteristics (such as turn-on / turn-off time, switching losses, di / dt, dv / dt, etc.) is a crucial step in evaluating device performance, optimizing drive circuits, and ensuring system reliability. Such testing typically needs to be performed in circuits operating under actual conditions or highly simulated conditions, where the commutation circuit's inductance is one of the core parameters affecting switching characteristics.

[0003] However, IGBT modules with different application scenarios and packaging forms have significant differences in internal structure, terminal layout, and application topology, resulting in large differences in the commutation loop inductance presented in actual applications. Currently, the conventional testing method is to customize and build a dedicated bus circuit for a specific model or specific inductance requirements, leading to extremely low test platform versatility. Moreover, each time the model of the device under test is changed or different commutation loop inductances need to be simulated, a dedicated bus structure often needs to be redesigned, manufactured, and assembled, resulting in long testing cycles and high material and engineering costs. Utility Model Content

[0004] To solve the above technical problems, this utility model provides an IGBT bus circuit with adjustable commutation loop inductance.

[0005] The technical problem solved by this utility model can be achieved by the following technical solution:

[0006] An IGBT bus circuit with adjustable commutation loop inductance includes:

[0007] Bus capacitor, which is connected in parallel across the DC power supply.

[0008] An adjustable commutation loop inductor, wherein the first end of the adjustable commutation loop inductor is connected to the first end of the bus capacitor;

[0009] The first IGBT device, wherein the collector of the first IGBT device is connected to the second terminal of the adjustable commutation loop inductance;

[0010] A host computer is connected to the adjustable switching circuit inductor and sends control commands to the adjustable switching circuit inductor.

[0011] Preferably, the adjustable commutation loop has multiple fixed inductance value settings, including 10nH, 20nH, 50nH and 100nH.

[0012] Preferably, the host computer pre-stores mapping data between application conditions and sensing value levels, including:

[0013] Photovoltaic power generation is matched to the 10nH setting;

[0014] New energy vehicles are equipped with a 20nH gear during operating conditions.

[0015] The 50nH range is suitable for medium and low voltage industrial frequency converter operation.

[0016] High-voltage industrial frequency converter is matched with the 100nH range.

[0017] Preferably, the control terminal of the adjustable commutator loop inductance is connected to the host computer.

[0018] Under the first control signal, the adjustable commutator loop noise inductance is selected at the 10nH level;

[0019] Under the second control signal, the adjustable commutator loop inductance is selected at the 20nH level;

[0020] Under the third control signal, the adjustable commutator loop inductance is selected at the 50nH level;

[0021] Under the fourth control signal, the adjustable commutator loop inductance is selected at the 100nH level.

[0022] Preferably, the control terminal of the adjustable commutation loop inductance is connected to the host computer through a mode selection circuit. The mode selection circuit includes multiple independent gear switching switches, and each gear switch is connected in series with the inductor coil group corresponding to the inductance value gear.

[0023] Preferably, the device further includes a second IGBT device, the collector of which is connected to the emitter of the first IGBT device, and the emitter of the second IGBT device is connected to the negative terminal of the DC power supply.

[0024] Preferably, it further includes a load inductor, which is connected between the collector and emitter of the first IGBT device.

[0025] Preferably, the bus capacitor is an electrolytic capacitor or a film capacitor, with its positive terminal connected to the positive terminal of the DC power supply and its negative terminal connected to the negative terminal of the DC power supply.

[0026] Preferably, the host computer communicates with the adjustable commutator loop noise inductance via a wired communication interface or a wireless communication module.

[0027] Beneficial effects: By adopting the above technical solutions, this utility model, through the introduction of adjustable commutator loop inductance L1 and host computer control architecture, realizes flexible adjustment of commutator loop inductance in IGBT module test platform, effectively solving the problems of poor versatility and high cost caused by customized bus structure in traditional test methods. Attached Figure Description

[0028] Figure 1 It is an IGBT bus circuit with fixed inductance in the converter circuit of existing technology;

[0029] Figure 2 This invention relates to an IGBT bus circuit with adjustable commutation circuit inductance. Detailed Implementation

[0030] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0031] It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0032] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but this is not intended to limit the present invention.

[0033] IGBT (Insulated Gate Bipolar Transistor) is a composite fully controllable power semiconductor device that combines the high input impedance of MOSFET and the low on-state voltage drop of BJT. It is widely used in high-frequency and high-power applications such as new energy vehicle drives, photovoltaic inverters, and industrial frequency converters.

[0034] Reference Figure 1 Currently, most mainstream IGBT testing bus circuits on the market employ a fixed stray inductance (commutation loop stray inductance) design. However, the application scenarios for IGBT devices vary significantly. For example, the commutation loop stray inductance for the new energy vehicle industry is approximately 25nH, while that for inverters in the traditional industrial control industry is approximately 50nH. This necessitates that the testing platform can flexibly match the stray inductance value of the target operating condition. Unfortunately, existing bus circuits with fixed commutation loop stray inductance lack versatility. For each new application requirement or device model, a new, customized bus circuit with a specific stray inductance value must be designed, manufactured, and built. This "one scenario, one design" approach suffers from low versatility and high testing costs.

[0035] To solve the above problems, refer to Figure 2 This utility model provides an IGBT bus circuit with adjustable commutation circuit inductance, comprising:

[0036] Bus capacitor C, which is connected in parallel across the DC power supply DC;

[0037] An adjustable commutation loop inductance L1 is provided, with its first end connected to the first end of the bus capacitor C.

[0038] The first IGBT device is IGBT 1, and the collector C1 of the first IGBT device IGBT 1 is connected to the second end of the adjustable commutation loop inductance L1.

[0039] A host computer (PC) is connected to the adjustable commutator loop inductor L1 and is used to send control commands to the adjustable commutator loop inductor L1.

[0040] Specifically, in this embodiment of the invention, an IGBT test bus circuit that flexibly adapts to different application scenarios is provided by introducing an adjustable commutation loop inductance L1 and PC control. This solution abandons the traditional fixed inductance design and adopts an adjustable inductor structure. The commutation loop inductance value is dynamically adjusted via commands from the PC, eliminating the need to customize the bus structure for different testing requirements. This significantly improves the versatility of the test platform, reduces repetitive design and manufacturing costs, and achieves more accurate operating condition simulation.

[0041] In a preferred embodiment of this utility model, the host computer (PC) communicates with the adjustable commutator loop inductor L1 via a wired communication interface.

[0042] Specifically, in this embodiment of the present invention, the host computer PC uses a Universal Asynchronous Receiver / Transmitter (UART), a Serial Peripheral Interface (SPI), and an Integrated Circuit Bus (I2C) to transmit data. 2 C. A wired communication interface, such as a controller area network (CAN) or Ethernet, is established with the adjustable commutator loop inductor L1 to achieve highly reliable remote control. This wired connection method features strong anti-interference capability and stable transmission, making it particularly suitable for testing environments with high communication reliability requirements, such as laboratories and production lines.

[0043] In addition, the host computer PC and the adjustable switching loop inductor L1 can communicate via a wireless communication module.

[0044] Specifically, in this embodiment of the invention, the wireless communication module employs technologies such as Wi-Fi, Bluetooth, or ZigBee to achieve wireless data transmission between the host PC and the adjustable commutator loop inductor L1. This wireless communication method not only reduces the wiring complexity of the test platform but also improves the system's flexibility, making it particularly suitable for field testing or high-power testing scenarios with limited space. It also supports multi-device networking and remote monitoring functions.

[0045] In a preferred embodiment of this utility model, the adjustable commutator loop inductance L1 is provided with multiple fixed inductance value ranges, including 10nH, 20nH, 50nH, and 100nH. The host computer PC pre-stores mapping data between application conditions and inductance value ranges, including:

[0046] Photovoltaic power generation is matched to the 10nH setting;

[0047] New energy vehicles are equipped with a 20nH gear during operating conditions.

[0048] The 50nH range is suitable for medium and low voltage industrial frequency converter operation.

[0049] High-voltage industrial frequency converter is matched with the 100nH range.

[0050] In a preferred embodiment of this invention, the control terminal of the adjustable commutation loop inductance L1 is connected to the host computer PC.

[0051] Under the first control signal, the adjustable commutator loop inductance L1 is selected at the 10nH level;

[0052] Under the second control signal, the adjustable commutator loop inductance L1 is selected at the 20nH level;

[0053] Under the third control signal, the adjustable commutator loop inductance L1 is selected at the 50nH level;

[0054] Under the fourth control signal, the adjustable commutator loop inductance L1 is selected at the 100nH level.

[0055] Specifically, in this embodiment of the invention, when a user inputs a specific application condition (such as "photovoltaic power generation") on the host computer PC, the host computer PC immediately calls the pre-stored mapping relationship database, automatically generates the corresponding control signal, and transmits it to the control terminal of the adjustable commutator loop inductor L1. This enables accurate simulation of different scenarios such as photovoltaic power generation, new energy vehicles, medium and low voltage industrial frequency conversion, and high voltage industrial frequency conversion, thereby significantly improving the flexibility and accuracy of IGBT module testing. At the same time, it avoids the high cost and long cycle problems caused by frequent replacement of customized bus structures in traditional methods, providing an efficient and economical solution for dynamic characteristic testing of power semiconductor devices.

[0056] In a preferred embodiment of this utility model, the control terminal of the adjustable commutation loop inductance L1 is connected to the host computer PC through a mode selection circuit. The mode selection circuit includes multiple independent gear switching switches, and each gear switch is connected in series with the inductor coil group corresponding to the inductance value gear.

[0057] Specifically, in this embodiment of the present invention, the mode selection circuit uses a relay array or semiconductor switching device to realize the rapid on / off control of the switching switches for each gear position. When the host computer PC sends a control signal corresponding to a specific working condition, the corresponding gear switch closes to connect the corresponding inductor coil group to the main circuit, while the other gears remain open, thereby ensuring the accurate switching of the inductance value of the converter circuit. At the same time, the electrical isolation design avoids signal interference, realizing high reliability selection and stable operation of the multi-gear inductors.

[0058] In a preferred embodiment of the present invention, a second IGBT device IGBT 2 is further included. The collector C2 of the second IGBT device IGBT 2 is connected to the emitter E1 of the first IGBT device IGBT 1, and the emitter E2 of the second IGBT device IGBT 2 is connected to the negative terminal of the DC power supply.

[0059] Specifically, in this embodiment of the invention, the circuit further integrates a second IGBT device, IGBT 2, whose collector C2 is directly connected to the emitter E1 of the first IGBT device, IGBT 1, while the emitter E2 is connected to the negative terminal of the DC power supply, forming a complete half-bridge topology. This design not only more realistically simulates the working state of the IGBT module in actual applications, especially the typical working condition of two transistors in series, but also enables the intelligent control of the adjustable commutation loop inductance L1 by the host computer PC, thereby achieving accurate testing of the dynamic characteristics under different switching modes, and thus comprehensively evaluating the performance of the IGBT device in complex application scenarios.

[0060] In a preferred embodiment of the present invention, a load inductor L2 is further included, which is connected between the collector C1 and the emitter E1 of the first IGBT device IGBT1 to simulate the inductance characteristics of an actual load.

[0061] Specifically, in this embodiment of the invention, the introduction of the load inductor L2 effectively simulates the inductive load condition in actual applications, and its inductance value can be precisely configured according to test requirements. The load inductor L2 is connected in parallel with the collector-emitter junction of the IGBT1, providing a freewheeling path when the IGBT1 is turned off, ensuring current continuity during the switching process. Simultaneously, it, together with the adjustable commutation loop stray inductance L1, constitutes a complete dynamic test environment. By adjusting the inductance parameters of the load inductor L2, the current change rate and voltage stress characteristics under different application scenarios can be realistically reproduced, providing accurate test conditions for evaluating key performance indicators such as switching losses and reverse recovery characteristics of the IGBT module under complex operating conditions.

[0062] In a preferred embodiment of this invention, the positive terminal of the bus capacitor C is connected to the positive terminal of the DC power supply, and the negative terminal is connected to the negative terminal of the DC power supply. The bus capacitor C can be an electrolytic capacitor or a film capacitor, etc.

[0063] Specifically, in this embodiment of the invention, the bus capacitor C adopts a parallel DC bus structure. Its positive terminal is directly connected to the positive terminal of the DC power supply, and its negative terminal forms a low-impedance path with the negative terminal of the DC power supply. This design effectively smooths DC bus voltage fluctuations through the charging and discharging characteristics of the capacitor. In terms of specific selection, the bus capacitor C can be an electrolytic capacitor or a film capacitor depending on the application scenario: electrolytic capacitors are suitable for scenarios with high capacitance requirements (e.g., >1000μF) and cost sensitivity, with low equivalent series resistance (ESR) but poor high-frequency characteristics; film capacitors (e.g., polypropylene PP material) are the preferred choice for high-frequency switching scenarios such as new energy vehicles due to their superior withstand voltage (up to several kilovolts), low ESL (<10nH), and long lifespan (>10,000 hours). Their capacitance calculation needs to consider the IGBT switching frequency (f), bus voltage ripple (ΔU), and power loss (P), using the formula C = (P × 2.5%) / (8 × f × U). 2 Determine the minimum tolerance and leave 20%-30% redundancy to cope with instantaneous pulse impacts.

[0064] The above description is only a preferred embodiment of the present utility model and does not limit the implementation method and protection scope of the present utility model. Those skilled in the art should realize that all solutions obtained by equivalent substitutions and obvious changes made based on the description and illustrations of the present utility model should be included within the protection scope of the present utility model.

Claims

1. An IGBT bus circuit with adjustable commutation loop inductance, characterized in that, include: Bus capacitor (C), which is connected in parallel across the two ends of a DC power supply (DC); An adjustable commutation loop inductor (L1) is provided, with its first terminal connected to the first terminal of the bus capacitor (C). The first IGBT device (IGBT 1) has its collector (C1) connected to the second terminal of the adjustable commutation loop inductance (L1). A host computer (PC) is connected to the adjustable switching loop inductor (L1) and sends control commands to the adjustable switching loop inductor (L1).

2. The IGBT bus circuit with adjustable commutator loop inductance according to claim 1, characterized in that, The adjustable commutation loop inductance (L1) is equipped with multiple fixed inductance value ranges, including 10nH, 20nH, 50nH and 100nH.

3. The IGBT bus circuit with adjustable commutator loop inductance according to claim 2, characterized in that, The host computer (PC) pre-stores mapping data between application conditions and sensing value levels, including: Photovoltaic power generation is matched to the 10nH setting; New energy vehicles are equipped with a 20nH gear during operating conditions. The 50nH range is suitable for medium and low voltage industrial frequency converter operation. High-voltage industrial frequency converter is matched with the 100nH range.

4. The IGBT bus circuit with adjustable commutator loop inductance according to claim 3, characterized in that, The control terminal of the adjustable commutation loop inductance (L1) is connected to the host computer (PC). Under the first control signal, the adjustable commutator loop inductance (L1) is selected at the 10nH level; Under the second control signal, the adjustable commutator loop inductance (L1) is selected at the 20nH level; Under the third control signal, the adjustable commutator loop inductance (L1) is selected at the 50nH level; Under the fourth control signal, the adjustable commutator loop inductance (L1) is selected at the 100nH level.

5. The IGBT bus circuit with adjustable commutation loop inductance according to claim 4, characterized in that, The control terminal of the adjustable commutation loop inductance (L1) is connected to the host computer (PC) through a mode selection circuit. The mode selection circuit includes multiple independent gear switching switches, and each gear switch is connected in series with the inductor coil group of the corresponding inductance value gear.

6. The IGBT bus circuit with adjustable commutator loop inductance according to claim 1, characterized in that, It also includes a second IGBT device (IGBT 2), the collector (C2) of the second IGBT device (IGBT 2) is connected to the emitter (E1) of the first IGBT device (IGBT 1), and the emitter (E2) of the second IGBT device (IGBT 2) is connected to the negative terminal of the DC power supply (DC).

7. The IGBT bus circuit with adjustable commutator loop inductance according to claim 1, characterized in that, It also includes a load inductor (L2) that is connected between the collector (C1) and emitter (E1) of the first IGBT device (IGBT 1).

8. The IGBT bus circuit with adjustable commutator loop inductance according to claim 1, characterized in that, The bus capacitor (C) is an electrolytic capacitor or a film capacitor.

9. The IGBT bus circuit with adjustable commutator loop inductance according to claim 1, characterized in that, The positive terminal of the bus capacitor (C) is connected to the positive terminal of the DC power supply (DC), and the negative terminal is connected to the negative terminal of the DC power supply (DC).

10. The IGBT bus circuit with adjustable commutation loop inductance according to claim 1, characterized in that, The host computer (PC) communicates with the adjustable commutator loop inductance (L1) via a wired communication interface or a wireless communication module.

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