IGBT parallel drive circuit

Abstract

The utility model provides an IGBT parallel drive circuit, relates to the field of power semiconductor devices, and solves the problem of drive consistency in parallel connection of IGBTs in the prior art. The circuit comprises at least one driving core and a plurality of adapter plates, the plurality of adapter plates are connected with the driving core in parallel, and each adapter plate is correspondingly connected with one IGBT module; the driving core is used for providing a unified driving signal for each adapter plate connected with the driving core in parallel, each adapter plate is used for providing driving current and gate protection for one IGBT module correspondingly connected with the adapter plate, and each adapter plate comprises a signal terminal, a plurality of common-mode filters, a push-pull circuit and a gate driving circuit; according to the utility model, the switching delay nonuniformity caused by the existing driving circuit can be reduced, the adverse effect of the parallel operation of the IGBTs is reduced, a plurality of parallel IGBT modules are successfully driven, and the cost reduction effect is realized.

Description

Technical Field

[0001] The utility model relates to the field of power semiconductor devices and is applied in the driving process of IGBTs. Specifically, it relates to a parallel driving circuit for IGBTs. Background Art

[0002] With the development of power electronics technology, IGBTs, as important power semiconductor devices, play a key role in various industrial applications, especially in fields such as energy storage systems, renewable energy power generation, and electric vehicle charging stations. IGBTs are favored for their high voltage withstand capacity, large current-carrying capacity, and fast switching characteristics.

[0003] However, commercially available IGBT modules on the market are usually designed and manufactured according to preset current ratings, such as 400A, 800A, etc. Although this hierarchical design method can meet the needs of most standardized applications, it has limitations in certain specific scenarios. For example, in applications that require non-standard current ratings such as 100A, 200A, 300A, 500A, 700A, etc., if a larger-rated IGBT module is directly used, it will result in a waste of current capacity, thereby increasing unnecessary costs. This is particularly prominent in a market environment with extremely strict cost control.

[0004] To overcome the above problems, a common solution is to use multiple IGBTs with small current ratings in parallel. This method can, to a certain extent, solve the problem of current rating mismatch and can achieve the required current rating by flexibly combining different numbers of small-current IGBTs, thereby reducing costs. However, using IGBTs in parallel also brings a series of new technical challenges and limitations:

[0005] Current sharing problem: There may be parameter differences (such as inconsistent on-resistance) between parallel IGBTs, which will lead to uneven current distribution among the IGBTs, thereby affecting the reliability and stability of the entire system.

[0006] Thermal management problem: When parallel IGBTs work, they generate heat. If the heat dissipation design is improper, it will cause local overheating, affecting the life and performance of the IGBTs.

[0007] Drive consistency: The drive circuit of parallel IGBTs needs to ensure that the drive signals of each IGBT are consistent to avoid current imbalance caused by switching delay.

[0008] Protection mechanism: When a certain IGBT fails, an effective protection mechanism is required to prevent the failure from further expanding and avoid damage to other IGBTs.

[0009] In summary, although the parallel use of low-current IGBTs can effectively reduce costs and meet the requirements of specific current ratings, a series of technical problems also need to be solved to ensure the reliability and efficiency of the system. Summary of the Invention

[0010] Based on the current situation in the background technology, the purpose of the present invention is to solve the problem of drive consistency existing in the parallel connection of IGBTs in the prior art. Therefore, an IGBT parallel drive circuit is proposed. The present invention uses a method of one drive core plus multiple adapter boards to drive all the parallel-connected IGBT modules. On this basis, each of the parallel-connected IGBT modules is made independent of each other, making the gate protection more effective. The present invention can reduce the unevenness of switching delay caused by the gate drive circuit, reduce the adverse effects of the parallel operation of IGBTs, successfully drive multiple parallel-connected IGBT modules, and achieve the cost reduction effect.

[0011] The present invention adopts the following technical solutions to achieve the purpose:

[0012] An IGBT parallel drive circuit includes at least one drive core and multiple adapter boards. The multiple adapter boards are connected to the drive core in parallel, and each adapter board is correspondingly connected to an IGBT module. The drive core is used to provide a unified drive signal to each adapter board connected in parallel with it, and each adapter board is used to provide drive current and gate protection to an IGBT module correspondingly connected to it.

[0013] Specifically, the drive core includes a signal interface, an isolated power supply, and a drive optocoupler. The signal interface is used to connect multiple adapter boards in parallel. The isolated power supply is used to provide an independent power supply isolated from the main circuit for the drive core. The drive optocoupler is used to provide electrical isolation between the signal interface and the adapter board.

[0014] Specifically, each adapter board includes a signal terminal, multiple common-mode filters, a push-pull circuit, and a gate drive circuit. The signal terminal is used to connect to the drive core. The common-mode filters are used to filter out interference on the connection line between the adapter board and the IGBT module. The push-pull circuit is used to provide drive current to the corresponding IGBT module. The gate drive circuit includes an IGBT drive resistor and is used to provide gate protection to the corresponding IGBT module.

[0015] Specifically, the signal terminal of the adapter board is connected to the corresponding IGBT module through four circuit connection lines. A common-mode filter is provided on each circuit connection line, and the four circuit connection lines together constitute a push-pull circuit and a gate drive circuit.

[0016] The four circuit connection lines include the first circuit connection line, the second circuit connection line, the third circuit connection line, and the fourth circuit connection line; the first circuit connection line leads out the positive power supply terminal of the push-pull circuit, the second circuit connection line leads out the negative power supply terminal of the push-pull circuit, the third circuit connection line leads out the detection terminal of the IGBT desaturation detection circuit, and the fourth power connection line forms part of the push-pull circuit and the gate drive circuit and is connected to the IGBT module.

[0017] In summary, due to the adoption of this technical solution, the beneficial effects of the present utility model are as follows:

[0018] The present utility model adopts a method of one drive core cooperating with multiple adapter boards. All parallel IGBT modules are uniformly driven by a single drive core, reducing the problem of inconsistent switching times caused by uneven delays in the drive circuit and improving the stability and reliability of the system. At the same time, in order to improve the effectiveness of gate protection, the present utility model integrates the gate protection circuit (such as gate resistors, TVS, RGE, CGE, etc.) on the adapter board, adjacent to the gate of the IGBT. This design helps to reduce the inductance of the gate loop, thereby reducing the switching loss and improving the response speed to transient voltages and currents, enhancing the safety and service life of the IGBT.

[0019] The present utility model integrates the push-pull circuit on the adapter board, providing independent drive current and gate protection circuit for each IGBT, realizing the lightweight design of the drive circuit and reducing the difficulty of device selection. By integrating the push-pull circuit and the gate protection circuit on the adapter board and ensuring the complete symmetry of the circuits between the adapter boards, the present utility model can ensure the consistency of the drive circuits between the parallel IGBT modules, further reducing the influence of uneven switching delays and improving the overall performance of the system.

[0020] The drive scheme proposed by the present utility model enables each IGBT to have an independent drive and protection circuit, which is not only convenient for maintenance and fault location, but also can easily increase or decrease the number of parallel IGBTs according to actual needs, improving the flexibility and scalability of the system. By adopting a centralized drive scheme and optimizing the specific layout design of the gate drive circuit, the present utility model can reduce the overall cost while ensuring the system performance. Description of the Drawings

[0021] Figure 1 It is a schematic diagram of the IGBT parallel connection structure of the present utility model;

[0022] Figure 2 It is a schematic diagram of the connection of the signal terminals of the adapter board in the present utility model;

[0023] Figure 3 It is one of the schematic diagrams of the four circuit connection lines of the adapter board in the present utility model;

[0024] Figure 4 This is the second schematic diagram of the four circuit connection lines of the adapter board in the present utility model. Detailed implementation manners

[0025] To make the objectives, technical solutions and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are some but not all of the embodiments of the present utility model. Usually, the components of the embodiments of the present utility model described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations.

[0026] Therefore, the following detailed description of the embodiments of the present utility model provided in the accompanying drawings is not intended to limit the scope of the claimed present utility model, but merely represents selected embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the scope of protection of the present utility model.

[0027] Embodiment

[0028] As Figure 1 shown, an IGBT parallel drive circuit includes at least one drive core and a plurality of adapter boards. The plurality of adapter boards are connected to the drive core in parallel, and each adapter board is correspondingly connected to an IGBT module; the drive core is used to provide a unified drive signal to each adapter board connected in parallel therewith, and each adapter board is used to provide drive current and gate protection to an IGBT module correspondingly connected therewith.

[0029] The above structural design of this embodiment can be applied to the parallel connection of multiple IGBT modules, such as the parallel connection of 2, 3 or preferably 4 IGBT modules. When multiple IGBT modules are connected in parallel, the symmetry of the structure needs to be considered for relevant circuit design to ensure a good current sharing effect.

[0030] In this embodiment, the drive core includes a signal interface, an isolated power supply and a drive optocoupler; the signal interface is used to connect multiple adapter boards in parallel, the isolated power supply is used to provide an independent power supply isolated from the main circuit (i.e., the application circuit where the IGBT module is located, such as a high-voltage circuit) for the drive core, and the drive optocoupler is used to provide electrical isolation between the signal interface and the adapter board. The signal interface of the drive core and the multiple adapter boards are connected by twisted pair cables, and the adapter board and the corresponding IGBT module are connected by welding, and the adapter board can be directly welded on the IGBT module.

[0031] In this embodiment, each adapter board includes signal terminals, multiple common-mode filters, a push-pull circuit, and a gate drive circuit; the signal terminals are used to connect to the drive core, the common-mode filters are used to filter out interference on the connection line between the adapter board and the IGBT module, the push-pull circuit is used to provide drive current to the corresponding IGBT module, and the gate drive circuit includes an IGBT drive resistor and is used to provide gate protection to the corresponding IGBT module. Similarly, the signal terminals of the adapter board and the drive core are connected by twisted pair cables, which can reduce interference during signal transmission to a certain extent.

[0032] Figure 2 The schematic diagram of the signal terminal J1 is shown. Usually, one adapter board is used to connect one IGBT module. However, for the case where the device is usually divided into an upper IGBT and a lower IGBT during use, the signal terminal J1 can have two sets of signal outputs and corresponding connected circuit structures to connect to the corresponding IGBT.

[0033] This embodiment combines Figure 3 and Figure 4 to introduce in detail the specific circuit structure when connecting one IGBT module or connecting one upper / lower IGBT. The signal terminal J1 of the adapter board is connected to the corresponding IGBT module through four circuit connection lines. A common-mode filter is provided on each circuit connection line, and the four circuit connection lines together constitute a push-pull circuit and a gate drive circuit.

[0034] In this embodiment, the four circuit connection lines include a first circuit connection line, a second circuit connection line, a third circuit connection line, and a fourth circuit connection line; each circuit connection line forms an intermediate point and is grounded through its respective common-mode filter, that is Figure 3 、 Figure 4 the intermediate point E0_1 and the ground GND0 in

[0035] As Figure 3 shown, the first circuit connection line includes a first common-mode filter L1, a solid-state capacitor C1, and a chip capacitor C2 connected in sequence starting from the signal terminal; the positive power supply terminal of the push-pull circuit is led out from the side of the chip capacitor C2 away from the solid-state capacitor C1; the second circuit connection line includes a second common-mode filter L2, a solid-state capacitor C3, and a chip capacitor C4 connected in sequence starting from the signal terminal; the negative power supply terminal of the push-pull circuit is led out from the side of the chip capacitor C4 away from the solid-state capacitor C3. The functions of the capacitors C1, C2, C3, and C4 are to form the power supply filter capacitors of the push-pull circuit.

[0036] As Figure 3As shown, the third circuit connection line includes a third common-mode filter, a chip resistor R1, a diode D1, and a diode D2 connected in sequence starting from the signal terminal; the third circuit connection line independently forms an IGBT desaturation detection circuit, and a detection terminal of the IGBT desaturation detection circuit is led out from the side of the diode D2 far from the diode D1.

[0037] Combined Figure 3 with Figure 4 , the fourth circuit connection line includes a fourth common-mode filter, a chip resistor R7, a chip resistor R3, and an IGBT drive resistor connected in sequence starting from the signal terminal; the IGBT drive resistor is connected to the IGBT module; the IGBT drive resistor is composed of a chip resistor R2, a chip resistor R4, and a chip resistor R6 connected in parallel; between the IGBT drive resistor and the IGBT module, a chip resistor R5 and a TVS diode D3 for providing gate protection are also connected in parallel to the IGBT module; the chip resistor R7 is used to provide a damping effect; an NPN transistor Q1 and a PNP transistor Q2 are also connected in parallel at the chip resistor R3, the bases of the NPN transistor Q1 and the PNP transistor Q2 are both connected to the same side of the chip resistor R3, the emitters of the NPN transistor Q1 and the PNP transistor Q2 are both connected to the other side of the chip resistor R3, the collector of the NPN transistor Q1 is the positive power supply terminal of the push-pull circuit, and the collector of the PNP transistor Q2 is the negative power supply terminal of the push-pull circuit; the IGBT drive resistor, the chip resistor R5, and the TVS diode D3 together form a gate drive circuit.

[0038] In this embodiment, the four common-mode filters L1 to L4 can filter out the interference generated on the transmission line and maintain the consistency of the signals received by multiple modules. The NPN transistor Q1, the PNP transistor Q2, and the chip resistor R3 form a push-pull circuit to provide a large current for driving the IGBT module. The chip resistor R5 and the TVS diode D3 for providing gate protection help balance the emitter voltage in case of a short circuit, avoid oscillation, and the chip resistor R5 helps limit the circulating current, damp oscillation, and achieve dynamic current sharing. The chip resistor R7 for providing a damping effect is a small-value resistor that can reduce the ringing phenomenon generated during the rising edge.

[0039] In summary, the IGBT parallel drive solution provided by the present utility model not only solves the problems of drive consistency and protection mechanism in traditional parallel technologies, but also effectively improves the reliability and efficiency of the system, while successfully reducing costs, and has good practical value and application prospects.

Claims

1. An IGBT parallel drive circuit, characterized in that: It includes at least one driver core and multiple adapter boards, which are connected to the driver core in parallel, and each adapter board is connected to an IGBT module accordingly; the driver core is used to provide a unified drive signal to each adapter board connected in parallel with it, and each adapter board is used to provide drive current and gate protection to an IGBT module connected to it accordingly.

2. The IGBT parallel drive circuit according to claim 1, characterized in that: The driver core includes a signal interface, an isolated power supply and a driver optocoupler; the signal interface is used to connect multiple adapter boards in parallel, the isolated power supply is used to provide the driver core with an independent power supply isolated from the main circuit, and the driver optocoupler is used to provide electrical isolation between the signal interface and the adapter board.

3. The IGBT parallel drive circuit according to claim 2, characterized in that: The signal interface of the driver core is connected to multiple adapter boards by twisted pair cables, and the adapter boards are connected to the corresponding IGBT modules by welding.

4. The IGBT parallel drive circuit according to claim 1, characterized in that: Each adapter board includes a signal terminal, multiple common-mode filters, a push-pull circuit and a gate drive circuit; the signal terminal is used to connect the drive core, the common-mode filter is used to filter out interference on the connection line between the adapter board and the IGBT module, the push-pull circuit is used to provide drive current to the corresponding IGBT module, and the gate drive circuit includes an IGBT drive resistor and is used to provide gate protection to the corresponding IGBT module.

5. The IGBT parallel drive circuit according to claim 4, characterized in that: The signal terminals of the adapter board are connected to the driver core using twisted pair cables.

6. The IGBT parallel drive circuit according to claim 4, characterized in that: The signal terminals of the adapter board are connected to the corresponding IGBT modules through four circuit connection lines, each of which is provided with a common mode filter, and the four circuit connection lines are combined to form a push-pull circuit and a gate drive circuit.

7. The IGBT parallel drive circuit according to claim 6, characterized in that: The four circuit connection lines include a first circuit connection line, a second circuit connection line, a third circuit connection line and a fourth circuit connection line; each circuit connection line forms an intermediate point through its own common mode filter and is grounded.

8. The IGBT parallel drive circuit according to claim 7, characterized in that: The first circuit connection line includes a first common mode filter L1, a solid capacitor C1 and a chip capacitor C2 which are connected in sequence from the signal terminal; the positive power terminal of the push-pull circuit is led out on the side of the chip capacitor C2 away from the solid capacitor C1; the second circuit connection line includes a second common mode filter L2, a solid capacitor C3 and a chip capacitor C4 which are connected in sequence from the signal terminal; the negative power terminal of the push-pull circuit is led out on the side of the chip capacitor C4 away from the solid capacitor C3.

9. The IGBT parallel drive circuit according to claim 8, characterized in that: The third circuit connection line includes a third common mode filter L3, a chip resistor R1, a diode D1 and a diode D2 which are connected in sequence from the signal terminal; the third circuit connection line alone constitutes an IGBT desaturation detection circuit, and a detection end of the IGBT desaturation detection circuit is led out on the side of the diode D2 away from the diode D1.

10. The IGBT parallel drive circuit according to claim 8, characterized in that: The fourth circuit connection line includes a fourth common mode filter L4, a chip resistor R7, a chip resistor R3, and an IGBT driving resistor connected in sequence from the signal terminal; the IGBT driving resistor is connected to the IGBT module; the IGBT driving resistor is composed of a chip resistor R2, a chip resistor R4, and a chip resistor R6 connected in parallel; between the IGBT driving resistor and the IGBT module, the IGBT module is also connected in parallel with a chip resistor R5 and a TVS tube D3 for providing gate protection; the chip resistor R7 is used to provide a damping effect; in the chip resistor R3 is also connected in parallel with an NPN transistor Q1 and a PNP transistor Q2. The bases of the NPN transistor Q1 and the PNP transistor Q2 are connected to the same side of the chip resistor R3, and the emitters of the NPN transistor Q1 and the PNP transistor Q2 are connected to the other side of the chip resistor R3. The collector of the NPN transistor Q1 is the positive power supply terminal of the push-pull circuit, and the collector of the PNP transistor Q2 is the negative power supply terminal of the push-pull circuit. The gate drive circuit is composed of the IGBT drive resistor, the chip resistor R5 and the TVS tube D3.

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