Pre-charging device of motor controller

Abstract

The invention provides a pre-charging device of a motor controller. The pre-charging device is applied to the motor controller of an electric vehicle. The pre-charging device comprises a power battery, a supporting capacitor, a contactor and a pre-charging circuit, wherein the contactor and the pre-charging circuit are arranged between a positive electrode of the power battery and a positive electrode of the supporting capacitor; the pre-charging circuit comprises a sequential control circuit and a pre-charging path; the pre-charging path comprises first and second pre-charging paths consisting of two MOS (Metal Oxide Semiconductor) transistors; the sequential control circuit is used for controlling sequential switch-on of the two MOS transistors. Through sequential switch-on of the first and second pre-charging paths, the supporting capacitor is charged. The pre-charging time is effectively shortened to facilitate driving; a conventional relay is substituted by using the MOS transistors, so that the performance is more stable and reliable.

Description

technical field [0001] The invention relates to a motor controller of an electric vehicle, in particular to a pre-charging device of the motor controller. Background technique [0002] In power electronics, when charging a capacitor, due to a sudden change in the voltage across the capacitor, an instantaneous large current will be generated at the beginning of charging. This current may cause high-voltage breakdown of the capacitor, and may also cause damage to the drive motor controller. damage to the circuit. Therefore, a pre-charging circuit is usually added to the high voltage or high current. Its main function is to limit the large current impact on the supporting capacitor when the power is turned on. It is mainly to slowly charge the supporting capacitor to a certain level before the main contactor is turned on. Voltage. For the inside of the drive motor controller, the pre-charging device can slow down the impact of high current on the internal circuit of the drive...

AI Technical Summary

Problems solved by technology

[0004] For the current electric buses and electric tourist buses, due to the weight of the body, the output capacity of the motor controller is required to reach more than 100 kVA to ensure the normal driving of the vehicle. Due to the large output capacity of the motor controller, the corresponding support capacitance The capacity must also be increased. If this invention is applied to this large-capacity motor controller, it will inevitably increase the pre-charging time and cause inconvenience to driving vehicles; Under the action of current, it will inevitably cause contact oxidation, damage, etc., resulting in the failure of the main contactor contacts to pull in and affect the normal driving of the vehicle.

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