Insulation monitoring device and monitoring method of power cell of electric vehicle

Abstract

The invention discloses an insulation monitoring device and method of a power cell of an electric vehicle. The insulation monitoring device comprises an electricity leakage detection circuit, a microprocessor, a signal generator and a signal collector, wherein the signal generator is connected with the chassis of the electric vehicle and the signal collector is connected with a sampling resistor. The signal generator is used for generating low-frequency voltage signals, and the signal collector is used for collecting voltage signals on the sampling resistor and transmitting the voltage signals to the microprocessor through a signal conditioning circuit; because the current flowing through the sampling resistor is the sum of the leakage current of the high-voltage system of the power cell and current generated by a low-frequency voltage signal transmitted by the signal generator, the microprocessor calculates an insulation resistance of a high-voltage system of a power cell on the chassis of the electric vehicle according to a current variation value; and when the insulation resistance of the high-voltage system of the power cell on the chassis of the electric vehicle is reduced to a preset response value, the microprocessor drives an alarming device to open and reminds a user to quickly carry out fault diagnosis, therefore ensuring the regular operation of the power cell and avoiding the potential safety hazard due to drop of insulation.

Description

[0001] technical field [0002] The invention relates to the detection of the insulation of a power battery of an electric vehicle, in particular to an insulation monitor and a monitoring method of the power battery of an electric vehicle. Background technique [0003] At present, the commonly used electric vehicle power battery insulation detection circuit generally adopts the terminal voltage method, the resistance method and the symmetrical voltage method. The short-circuit fault inside the battery, the symmetrical voltage method cannot measure when positive and negative symmetrical faults occur inside the power battery, and the ability to resist leakage capacitance interference is poor. Contents of the invention [0004] The technical problem to be solved by the present invention is to provide an insulation monitor and monitoring method for the power battery of an electric vehicle, which monitors the insulation performance between the high voltage system of the power b...

AI Technical Summary

Problems solved by technology

[0003] At present, the commonly used electric vehicle power battery insulation detection circuit generally adopts the terminal voltage method, the resistance method and the symmetrical voltage method. Short circuit fault inside the battery, the symmetrical voltage method cannot measure when positive and negative symmetrical faults occur inside the power battery, and the ability to resist leakage capacitance interference is poor

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