Active discharge circuit and power electronic equipment

Abstract

The embodiment of the invention discloses an active discharge circuit and power electronic equipment. The active discharge circuit is used for discharging a direct current bus capacitor connected between a positive bus and a negative bus in a driving device. The active discharge circuit comprises a control unit, a switch tube and a discharge resistor, and the switch tube and the discharge resistorare connected in series and then are connected with the direct current bus capacitor in parallel; the active discharge circuit also comprises a driving branch circuit. The control unit is connected to the control end of the switch tube through the driving branch, and when the control unit outputs a discharge signal or the control unit fails, the driving branch drives the switch tube to be switched on in a preset mode according to the voltage at the two ends of the direct-current bus capacitor so as to prevent the discharge resistor from being burnt out.

Description

technical field [0001] Embodiments of the present invention relate to the field of electronic power, in particular to an active discharge circuit and power electronic equipment. Background technique [0002] The motor controller is the key unit in the electric vehicle. In the motor controller, the DC bus capacitor is used as the input of the inverter, and the inverter outputs three-phase AC to drive the permanent magnet synchronous motor, thereby driving the electric vehicle to run normally. When parking, vehicle collision or controller failure, the contactor between the bus capacitor and the battery will be disconnected. Since there is still high voltage on the bus capacitor, if it is not released in time, it will bring safety risks to personnel. For the sake of safety, in the above cases, the voltage at both ends of the DC bus capacitor is generally reduced to below 60V through an active discharge circuit. Commonly used active discharge circuit forms include bridge arm th...

AI Technical Summary

Problems solved by technology

[0004] The embodiment of the present invention aims at the problems that when the DC bus capacitor is connected in parallel at both ends of the discharge resistor, the power to the discharge resistor is very high, and the resulting discharge resistor has a large volume, high cost, and large space for heat dissipation, and provides an active discharge circuit and power electronics

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