T-type three-level power module for motor controller and vehicle

Abstract

The application provides a T-type three-level power module applied to a motor controller to solve the problems of the existing full SiC T-type three-level power module in terms of loss, efficiency, cost and heat dissipation. The module comprises a first capacitor, a second capacitor, a vertical bridge circuit with three vertical bridge arms, a horizontal bridge circuit with three horizontal bridge arms and a neutral point; two ends of the first capacitor are connected with a positive electrode of a bus and the neutral point respectively, and two ends of the second capacitor are connected with a negative electrode of the bus and the neutral point respectively; each horizontal bridge arm of the horizontal bridge circuit comprises two second switch tubes connected in reverse, and the connection points of the two second switch tubes are output ends of the corresponding vertical bridge arms; each vertical bridge arm of the vertical bridge circuit comprises two first switch tubes connected in series, and the connection points of the two first switch tubes are output ends of the corresponding horizontal bridge arms; the first switch tube adopts an IGBT switch tube; and the second switch tube adopts an SIC switch tube.

Description

Technical Field

[0001] This application relates to the field of vehicle motor controllers, specifically a T-type three-level power module for use in a motor controller and a vehicle. Background Technology

[0002] Existing traditional T-type three-level IGBT modules, such as Figure 1 Or use SiC modules Figure 2 Problems and drawbacks of existing technologies: all IGBT modules have high losses and low efficiency; all SiC modules have high costs and high prices. Summary of the Invention

[0003] This application provides a T-type three-level power module for use in motor controllers to solve the problems of insufficient loss, efficiency, cost and heat dissipation in existing all-IGBT three-level solutions.

[0004] The technical solution of this application is as follows: This application provides a T-type three-level power module for use in a motor controller, including: 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 an IGBT switching transistor; the second switching transistor is a SiC switching transistor.

[0005] Each vertical bridge arm of the horizontal bridge circuit also includes two diodes connected in reverse series, and the diodes are SiC diodes.

[0006] This application also provides a vehicle including the aforementioned T-type three-level power module used in a motor controller.

[0007] The beneficial effects of this application are as follows: Based on the loss distribution characteristics of the T-type three-level topology, the vertical bridge arm with high voltage, high current, and low switching frequency retains IGBTs to take advantage of their on-state voltage drop and cost. The horizontal bridge arm with high-frequency commutation and concentrated losses, as well as the neutral point path, are replaced with SiC switching transistors + SiC diodes, utilizing their extremely low switching losses and fast recovery characteristics. In principle, this achieves: a significant reduction in midpoint commutation loss, an increase in overall switching frequency, and a reduction in the size of magnetic components, while maintaining the cost and current carrying capacity of the IGBT section. Ultimately, this achieves a "high efficiency-low cost" tradeoff, with improved efficiency, reduced heat dissipation pressure, and only a slight increase in cost. Attached Figure Description

[0008] 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 a prior art T-type three-level power module; Figure 3 This is a circuit diagram of the T-type three-level power module 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; Figure 5 This is a schematic diagram of the switching loss and CLTC overall efficiency test results in the embodiments of this application. Detailed Implementation

[0009] Reference Figure 3 This application provides a T-type three-level power module for use in a motor controller, 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 an IGBT switching transistor; the second switching transistor is a SiC switching transistor.

[0010] Each vertical bridge arm of the horizontal bridge circuit also includes two diodes connected in reverse series, and the diodes are SiC diodes.

[0011] By leveraging the loss distribution characteristics of the T-type three-level topology, the vertical bridge arm with high voltage, high current, and low switching frequency retains IGBTs to utilize their on-state voltage drop and cost advantages. Meanwhile, the horizontal bridge arm with high-frequency commutation and concentrated losses, as well as the neutral point path, are replaced with SiC switching transistors and SiC diodes, utilizing their extremely low switching losses and fast recovery characteristics. In principle, this achieves: a significant reduction in midpoint commutation losses, an increase in overall switching frequency, and a reduction in the size of magnetic components, while maintaining the cost and current carrying capacity of the IGBT section. Ultimately, this achieves a "high efficiency-low cost" tradeoff, with improved efficiency, reduced heat dissipation pressure, and only a slight increase in cost.

[0012] The vertical bridge circuit consists of three vertical bridge arms, each composed of two first-phase switching transistors connected in series. The upper end is connected to P, the lower end to N, and the midpoint is connected to the corresponding phase winding of the motor. The first-phase switching transistors are IGBTs, which utilize their mature technology and low cost to handle the voltage and current of the main power path.

[0013] The cross-bridge circuit consists of three cross-bridge arms, each composed of two second switching transistors connected in reverse series. One end of each arm is connected to the output terminal of the corresponding vertical bridge arm, and the other end is connected to the neutral point O. The second switching transistors are SiC MOSFETs, which utilize their high switching speed to achieve midpoint clamping and reduce high-frequency commutation losses.

[0014] The cross-bridge arm also contains two SiC Schottky diodes connected in reverse series, which together with the SiC MOSFET form a bidirectional freewheeling path to prevent reverse recovery charge and suppress voltage overshoot.

[0015] During operation, the vertical bridge arm IGBTs conduct complementaryly according to the modulation strategy, outputting positive, zero, and negative levels; the horizontal bridge arm SiC MOSFETs selectively conduct according to the current direction, so that the midpoint O forms a freewheeling loop in the zero-level stage. The IGBTs are responsible for low-frequency high-current conduction, while the SiC devices are responsible for high-frequency switching. The two functions are divided and work together to complete the three-level commutation.

[0016] This hybrid solution reduces on-state costs using IGBTs and reduces switching losses using SiC without requiring additional heat sinks, making it suitable for motor drive systems that require both efficiency and cost.

[0017] After all IGBT modules underwent bench calibration testing, such as Figure 4 After loss simulation, it was found that under CLTC operating conditions, the conduction loss of T-tubes accounted for the majority, with IGBT and Diode having particularly large conduction losses. The calculation showed that the overall efficiency of the electronically controlled CLTC was only about 97.4%.

[0018] like Figure 5 As shown, after adopting the hybrid T-type three-level module, the conduction loss of SiC and SiC diodes is significantly lower than that of IGBT and Si diodes under the small current of CLTC. Therefore, after loss simulation, the overall efficiency of the hybrid T-type three-level CLTC is 98.6%, which is higher than that of the pure IGBT solution.

[0019] This application also provides a vehicle including the aforementioned T-type three-level power module based on SiC and IGBT hybrid connection used in a motor controller.

[0020] 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 used in a motor controller, 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 an IGBT switching transistor; the second switching transistor is a SiC switching transistor.

2. The T-type three-level power module for 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 SiC diodes.

3. A vehicle, characterized in that, Includes the T-type three-level power module for use in a motor controller as described in any one of claims 1-2.

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