Electrically-driven special vehicle distributed capacitance testing device

Abstract

The invention belongs to the technical field of special vehicle comprehensive power system high-voltage safety protection, and particularly relates to an electrically-driven special vehicle distributed capacitance testing device which comprises a precise current source, a reference voltage source, an electronic switch, a voltage comparator, an electronic switch control unit and a single-chip microcomputer. The device enables the reference voltage source to charge the distributed capacitor through switching the electronic switch, discharges the distributed capacitor through the precision current source, records the discharge time of the distributed capacitor through the single-chip microcomputer, and obtains the capacitance value of the distributed capacitor according to a capacitance calculation formula. The circuit realizes the distributed capacitance detection function of the electrically-driven special vehicle, can measure the distributed capacitance value of the vehicle, and provides a basis for the duration of applying insulation detection excitation voltage to an on-vehicle insulation detection device. And meanwhile, an electric leakage subcircuit of the vehicle caused by distributed capacitance is effectively evaluated, the electric shock risk of personnel is reduced, and the safety of personnel and equipment on the vehicle is effectively ensured.

Description

technical field [0001] The invention belongs to the technical field of high-voltage safety protection of comprehensive power systems of special vehicles, and in particular relates to a distributed capacitance testing device for electric-driven special vehicles. Background technique [0002] With the vigorous development of vehicle power battery technology, electric actuation technology, and vehicle-mounted high-power power generation technology, electric-driven special vehicles are widely used in various fields of social production and life. However, different from traditional vehicles, the internal electrical equipment of electric drive vehicles is mainly driven by motors, and the main control method is high-frequency PWM chopper control. This results in a complex electromagnetic environment inside the vehicle. In order to improve the anti-electromagnetic interference capability of the equipment, Y capacitors are usually installed between the high-voltage bus and the shell ...

AI Technical Summary

Problems solved by technology

[0004] However, if the distributed capacitance or Y capacitance on the vehicle is too large, it will have a certain impact on the accuracy of insulation resistance detection, and false alarms or no alarms may occur.

At the same time, when the insulation of the single busbar is lowered to the shell, a leakage circuit will be formed through the distributed capacitance or Y capacitance, and there is a potential risk of electric shock

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