Motor controller busbar capacitor charge-discharge circuit

Abstract

The invention discloses a motor controller busbar capacitor charge-discharge circuit which comprises a power battery, a pre-charge resistor, a power switching device, a main control chip, a busbar capacitor, a power switching circuit and a discharge resistor; the power battery is electrically connected with the pre-charge resistor, the pre-charge resistor is electrically connected with the power switching device, the power switching device is electrically connected with the busbar capacitor, the busbar capacitor is electrically connected with the power switching circuit, and the power switching circuit is electrically connected with the discharge resistor; the main control chip is in control connection with the power battery, the power switching device and the busbar capacitor, and the power battery is electrically connected with the power switching circuit. The problem that pre-charge inside the controller is invalid is solved by the aid of the motor controller busbar capacitor charge-discharge circuit, safer and more effective busbar capacitor charge-discharge can be realized, busbar normally-hanged parallel connection high-power discharge resistance can be removed by the aid ofthe design of the discharge circuit, and the discharge speed is accelerated.

Description

technical field [0001] The invention belongs to the field of discharge circuits, and relates to a motor controller, in particular to a motor controller bus capacitor charging and discharging circuit. Background technique [0002] There are two main ways to realize the charging and discharging of the bus capacitor of the existing motor controller. One is to use the thermistor inside the controller to increase the power resistance of the pre-charging method. The thermistor is mainly a PTC thermistor. Due to the positive temperature coefficient characteristic of PTC, there may be cases where the battery cannot be charged, resulting in the failure of the pre-charging circuit. The discharge is mainly achieved by a high-power resistor connected in parallel to the bus capacitor, and the discharge resistor is often hung on the DC bus capacitor to generate power loss. [0003] The other is that there is an auxiliary pre-charging circuit outside the controller. The VCU or BMS of the ...

AI Technical Summary

Problems solved by technology

[0002] There are two main ways to realize the charging and discharging of the bus capacitor of the existing motor controller. One is to use the thermistor inside the controller to increase the power resistance of the pre-charging method. The thermistor is mainly a PTC thermistor. Due to the positive temperature coefficient characteristics of PTC, there will be cases where the power cannot be charged, resulting in the failure of the pre-charging circuit

The discharge is mainly realized by a high-power resistor connected in parallel to the bus capacitor, and the discharge resistor is often hung on the DC bus capacitor to generate power loss

[0003] The other is that there is an auxiliary pre-charging circuit outside the controller. The VCU or BMS of the vehicle controls the pre-charging relay to pre-charge the bus capacitor of the controller. The controller does not perform any operation. The heat accumulation in the pre-charging resistance and the load cut-off of the relay will result in damage to the pre-charging resistance or burning of the pre-charging relay

The above two methods have disadvantages, especially when the controller bus capacitor is connected in parallel with a high-power resistor, the passive discharge speed is slow, and unnecessary power loss will be generated.

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