SiC and gan hybrid t-type three-level power module and vehicle
Patent Information
- Application Number
- CN202522317995.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-31
- Publication Date
- 2026-09-22
- Estimated Expiration
- 2035-10-31
AI Technical Summary
[0008]本申请提供了一种运用于电机控制器的基于SiC和GAN混联的T型三电平功率模块，以解决现有的全SiC T型三电平方案在损耗、效率、成本及散热方面不足的问题
通过把 T 型三电平拓扑中的横臂开关（T 管）改为 GaN 器件，竖臂仍保留 SiC器件：竖臂承担高电压，利用 SiC 的高耐压与高温能力；横臂只承受一半母线电压，却需频繁换流，改用 GaN 后，其低 Qg、低 Coss 和零反向恢复电荷把中点钳位过程的开关损耗和驱动损耗显著压低，同时 GaN 的横向结构无需额外反并二极管即可实现双向导通，使整机在保持三电平低谐波、低 dv/dt 优势的前提下，进一步降低损耗、减少器件数量、缩小散热体积，并缓解高频下 SiC 全桥方案成本与热集中问题，从而以混联方式同时达到高效率、高功率密度与低成本的目标。
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Figure CN224790556U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of vehicle motor controllers, specifically a T-type three-level power module based on a hybrid SiC and GAN and a vehicle. Background Technology
[0002] The T-type three-level topology is widely used in photovoltaic inverters, energy storage converters, and motor drives due to its high number of output levels and low harmonics. Combined with... Figure 1 The common approach is to combine the two-level bridge arm with the bidirectional midpoint clamping branch and use a full SiC power module in order to reduce the size of passive devices by utilizing the high-frequency characteristics of SiC devices.
[0003] However, the all-SiC module still has the following shortcomings in the T-type three-level circuit: 1. High switching losses The T-type topology requires at least four SiC devices to participate in commutation in each phase. The large number of devices results in a higher total switching energy than the two-level or NPC topology, leading to a significant increase in losses at high frequencies.
[0004] 2. Limited efficiency improvement The SiC MOSFET body diode in the clamping branch still needs to periodically freewheel. Although the reverse recovery charge is lower than that of silicon devices, it still generates additional tail current during the three-level commutation process, which limits the further improvement of the overall efficiency.
[0005] 3. High cost Each phase requires at least four 1200 V SiC MOSFET chips. The large number of devices and the higher unit price of SiC chips compared to silicon IGBTs of the same specifications result in a high proportion of power device costs.
[0006] 4. High heat dissipation pressure When multiple chips are connected in parallel, the heat density is concentrated, and the reduction in module thermal resistance is limited. This requires increasing the size of the heat sink, which offsets the size advantage brought by high frequency.
[0007] Therefore, the existing all-SiC T-type three-level solution still needs improvement in terms of loss, efficiency, cost, and heat dissipation. Summary of the Invention
[0008] This application provides a T-type three-level power module based on a hybrid SiC and GAN configuration for use in motor controllers, in order to solve the problems of insufficient loss, efficiency, cost and heat dissipation in existing all-SiC T-type three-level solutions.
[0009] The technical solution of this application is as follows: This application provides a T-type three-level power module based on SiC and GAN hybrid connection for use in motor controllers, including: a first capacitor (C1), a second capacitor (C2), a vertical bridge circuit with three vertical bridge arms, a horizontal bridge circuit with three horizontal bridge arms, and a neutral point (O). The two ends of the first capacitor (C1) are connected to the positive terminal and the neutral point (O) of the busbar, respectively, and the two ends of the second capacitor (C2) are connected to the negative terminal and the neutral point (O) of the busbar, respectively. The two ends of each vertical bridge arm of the vertical bridge circuit are connected to the positive and negative poles of the busbar, respectively, and the output end of each vertical bridge arm of the vertical bridge circuit is connected to the motor. One end of each horizontal bridge arm of the horizontal bridge circuit is connected to the output terminal of a vertical bridge arm, and the other end is connected to the neutral point (O). Each horizontal bridge arm of the horizontal bridge circuit includes two second switches connected in reverse series. The connection point of the two second switches is the output terminal of the corresponding vertical bridge arm. Each vertical bridge arm of the vertical bridge circuit includes two first switching transistors connected in series, and the connection point of the two first switching transistors is the output terminal of the corresponding horizontal bridge arm; The first switching transistor is a SiC switching transistor; the second switching transistor is a GaN switching transistor.
[0010] Each vertical bridge arm of the horizontal bridge circuit also includes two diodes connected in reverse series, and the diodes are GaN Schottky diodes.
[0011] This application also provides a vehicle including the aforementioned T-type three-level power module based on a hybrid SiC and GAN configuration used in a motor controller.
[0012] The beneficial effects of this application are as follows: By replacing the horizontal arm switch (T-transistor) in the T-type three-level topology with a GaN device, while retaining the SiC device in the vertical arm, the vertical arm bears the high voltage, utilizing the high voltage withstand and high temperature capability of SiC. The horizontal arm only bears half of the bus voltage but requires frequent commutation. After switching to GaN, its low Qg, low Coss, and zero reverse recovery charge significantly reduce the switching and driving losses in the midpoint clamping process. At the same time, the lateral structure of GaN can achieve bidirectional conduction without additional anti-parallel diodes. This allows the entire system to further reduce losses, reduce the number of devices, and shrink the heat dissipation volume while maintaining the advantages of low harmonics and low dv / dt of the three-level topology. It also alleviates the cost and heat concentration problems of the SiC full-bridge solution at high frequencies, thus achieving the goals of high efficiency, high power density, and low cost in a hybrid configuration. Attached Figure Description
[0013] Figure 1 This is a circuit diagram of a prior art T-type three-level power module; Figure 2 This is a circuit diagram of the T-type three-level power module in the embodiments of this application; Figure 3 This is a schematic diagram of the switching loss and CLTC overall efficiency test results in the embodiments of this application; Figure 4 This is a schematic diagram of the switching loss and CLTC overall efficiency test results in the embodiments of this application. Detailed Implementation
[0014] Reference Figure 2 This application provides a T-type three-level power module based on SiC and GAN hybrid connection for use in motor controllers, including: a first capacitor C1, a second capacitor C2, a vertical bridge circuit with three vertical bridge arms, a horizontal bridge circuit with three horizontal bridge arms, and a neutral point O. The two ends of the first capacitor C1 are connected to the positive terminal of the busbar and the neutral point O, respectively; the two ends of the second capacitor C2 are connected to the negative terminal of the busbar and the neutral point O, respectively. The two ends of each vertical bridge arm of the vertical bridge circuit are connected to the positive and negative poles of the busbar, respectively, and the output end of each vertical bridge arm of the vertical bridge circuit is connected to the motor. Each horizontal bridge arm of the horizontal bridge circuit is connected at one end to the output terminal of a vertical bridge arm, and at the other end to the neutral point O. Each horizontal bridge arm of the horizontal bridge circuit includes two second switches connected in reverse series. The connection point of the two second switches is the output terminal of the corresponding vertical bridge arm. Each vertical bridge arm of the vertical bridge circuit includes two first switching transistors connected in series, and the connection point of the two first switching transistors is the output terminal of the corresponding horizontal bridge arm; The first switching transistor is a SiC switching transistor; the second switching transistor is a GaN switching transistor.
[0015] Each arm of the cross-bridge circuit also includes two diodes connected in reverse series, which are GaN Schottky diodes.
[0016] By forming a complete three-phase T-type three-level topology between the DC side, AC side, and neutral point, and through the partitioning of device types, comprehensive optimization of loss, cost, and power density is achieved. The positive terminal of the first capacitor C1 is connected to the positive terminal P of the DC bus, and the negative terminal is connected to the neutral point O; the positive terminal of the second capacitor C2 is connected to the neutral point O, and the negative terminal is connected to the negative terminal N of the DC bus; C1 and C2 are connected in series to form a capacitor voltage divider branch, providing the midpoint potential for the T-type three-level circuit.
[0017] The vertical bridge circuit consists of three vertical bridge arms, corresponding to the U, V, and W phases of the motor, respectively. The upper end of each vertical bridge arm is connected to the positive terminal P of the DC bus, and the lower end is connected to the negative terminal N of the DC bus. The midpoint terminal of the vertical bridge arm is directly used as the output terminal of that phase for connecting the motor windings.
[0018] Each vertical bridge arm consists of two first switching transistors (SiC) connected in series, and the connection point of the two transistors forms the output terminal of that phase; the first switching transistor is a SiC switching transistor, which uses its vertical withstand voltage structure to withstand the full bus voltage.
[0019] The horizontal bridge circuit comprises three horizontal arms, each corresponding to one of the three vertical bridge arms. The first end of each horizontal bridge arm is connected to the output of the corresponding vertical bridge arm, and the second end is uniformly connected to the neutral point O, thus providing a midpoint current path during three-level commutation. Each horizontal bridge arm consists of two anti-tandem second switching transistors (GaN), and the connection point of the two transistors forms the output of that phase. The second switching transistors are GaN transistors, utilizing their lateral device structure to achieve fast turn-on and turn-off. The horizontal bridge circuit comprises three horizontal arms, each corresponding to one of the three vertical bridge arms. The first end of each horizontal bridge arm is connected to the output of the corresponding vertical bridge arm, and the second end is uniformly connected to the neutral point O, thus providing a midpoint current path during three-level commutation. Each horizontal bridge arm consists of two anti-tandem second switching transistors, and the connection point of the two transistors forms the output of that phase. The second switching transistors are SiC transistors, utilizing their vertical withstand voltage structure to withstand bidirectional voltage stress during midpoint clamping.
[0020] The SiC switch in the vertical bridge arm is responsible for voltage blocking and low-frequency commutation of the main power path, reducing conduction losses; the GaN switch in the horizontal bridge arm is responsible for bidirectional clamping at the midpoint and high-frequency commutation, reducing switching and drive losses. Through the above partitioning, a hybrid strategy of "SiC for high-voltage segments and GaN for high-frequency segments" is achieved, avoiding the problems of a large number of devices and superimposed losses in the all-SiC solution, while reducing the withstand voltage pressure of the pure GaN solution at the 1200 V level.
[0021] During three-level modulation, the two SiC switches in the vertical bridge arm operate complementaryly according to the "positive-zero-negative" level requirements; the two GaN switches in the horizontal bridge arm selectively conduct according to the current direction, providing a low-impedance loop at the midpoint O during the freewheeling phase, thus completing level clamping. Since the horizontal bridge arm only handles the midpoint current, its conduction time is relatively short, resulting in a limited proportion of conduction losses for the SiC devices, while the GaN devices can fully leverage their high-speed advantage to perform the main commutation task.
[0022] The above structure maintains the advantages of low harmonics and low dv / dt of T-type three-level circuits, while leveraging the respective advantages of SiC and GaN in terms of frequency band and voltage withstand characteristics to reduce the overall number of devices, lower drive and switching losses, and balance cost control with power density improvement.
[0023] like Figure 3 In this embodiment, the switching losses of the switching transistor and its diode account for 13.89%, and the overall efficiency of the CLTC is 98.9%. By using GaN as the switching transistor, the switching losses of both the transistor and its diode are significantly reduced, such as... Figure 4 The difference is negligible, and the overall efficiency of CLTC is 99.3%, indicating an improvement in efficiency.
[0024] By replacing the horizontal arm switch (T-transistor) in the T-type three-level topology with a GaN device, while retaining the SiC device in the vertical arm, the vertical arm bears the high voltage, utilizing the high voltage withstand and high temperature capability of SiC. The horizontal arm only bears half of the bus voltage but requires frequent commutation. After switching to GaN, its low Qg, low Coss, and zero reverse recovery charge significantly reduce the switching and driving losses in the midpoint clamping process. At the same time, the lateral structure of GaN can achieve bidirectional conduction without additional anti-parallel diodes. This allows the entire system to further reduce losses, reduce the number of devices, and shrink the heat dissipation volume while maintaining the advantages of low harmonics and low dv / dt of the three-level topology. It also alleviates the cost and heat concentration problems of the SiC full-bridge solution at high frequencies, thus achieving the goals of high efficiency, high power density, and low cost in a hybrid configuration.
[0025] This application also provides a vehicle including the aforementioned T-type three-level power module based on a hybrid SiC and GAN configuration used in a motor controller.
[0026] It should be understood that the application of this application is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims. Those skilled in the art can understand that implementing all or part of the processes of the above embodiments and making equivalent changes according to the claims of this application still fall within the scope of this application.
Claims
1. A T-type three-level power module based on a hybrid SiC and GAN configuration for use in motor controllers, characterized in that, include: A first capacitor (C1), a second capacitor (C2), a vertical bridge circuit with three vertical arms, a horizontal bridge circuit with three horizontal arms, and a neutral point (O). The two ends of the first capacitor (C1) are connected to the positive terminal and the neutral point (O) of the busbar, respectively, and the two ends of the second capacitor (C2) are connected to the negative terminal and the neutral point (O) of the busbar, respectively. The two ends of each vertical bridge arm of the vertical bridge circuit are connected to the positive and negative poles of the busbar, respectively, and the output end of each vertical bridge arm of the vertical bridge circuit is connected to the motor. One end of each horizontal bridge arm of the horizontal bridge circuit is connected to the output terminal of a vertical bridge arm, and the other end is connected to the neutral point (O). Each horizontal bridge arm of the horizontal bridge circuit includes two second switches connected in reverse series. The connection point of the two second switches is the output terminal of the corresponding vertical bridge arm. Each vertical bridge arm of the vertical bridge circuit includes two first switching transistors connected in series, and the connection point of the two first switching transistors is the output terminal of the corresponding horizontal bridge arm; The first switching transistor is a SiC switching transistor; the second switching transistor is a GaN switching transistor.
2. The T-type three-level power module based on SiC and GAN hybrid connection used in motor controllers according to claim 1, characterized in that, Each vertical arm of the horizontal bridge circuit also includes two diodes connected in reverse series, which are GaN Schottky diodes.
3. A vehicle, characterized in that, Includes the T-type three-level power module based on SiC and GAN hybrid connection used in motor controllers as described in any one of claims 1-2.