Electric-vehicle battery pack direct-current ground-insulation resistance detection device and method

Abstract

The invention discloses an electric-vehicle battery pack direct-current ground-insulation resistance detection device and method, which are used for detection of a ground-insulation resistance value of an electric-vehicle high-voltage system. The device and the method include a signal loop, a pulse generation unit, a drive unit, a sampling unit, a processor and the like. The pulse generation unitgenerates a current, the current flows through a measured insulation resistor into a battery pack, and then flows through diodes, a current limiting resistor and a sampling resistor to return to the pulse generation unit, and a current loop is constructed. The sampling unit collects a voltage value on the sampling resistor, and carries out signal processing. The processor outputs a pulse drive signal, and the pulse signal is formed by chopping on a driving power source; and at the same time, the processor receives a voltage signal of the sampling unit for analog / digital conversion, and finallycalculates equivalent resistance of the battery pack to the ground through the voltage value of sampling. The method and the device can realize detection of a ground-insulation resistance value of any position inside the battery pack and fault position locking without impacts on a vehicle body system.

Description

technical field [0001] The invention relates to the technical field of electric vehicle battery packs, in particular to a device and method for detecting DC-to-ground insulation resistance of electric vehicle battery packs. Background technique [0002] With the increasing energy crisis and environmental pollution, the development of high-efficiency, energy-saving, and zero-emission clean electric vehicles has become an inevitable trend in the development of the domestic and foreign automobile industries. With the requirements of the national standard GB / T18384.3-2015 for personal electric shock protection, all electric vehicle manufacturers have regarded the insulation safety performance of high-voltage power battery packs as the top priority. [0003] The working process of the traditional bias resistance switching detection method for the insulation resistance of the high-voltage power battery pack of pure electric vehicles is unreliable, cannot respond to the ground insu...

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Problems solved by technology

[0005] Aiming at the deficiencies of the prior art, the present invention provides a DC-to-ground insulation resistance detection device and method of an electric vehicle battery pack, which solves the problems in the working process of the bias resistance switching detection method of the current high-voltage power battery pack insulation resistance of pure electric vehicles. Unreliability, unable to respond to the ground insulation fault that occurs inside the power battery pack, and at the same time has a strong dependence on the DC high voltage of the battery pack, and cannot realize zero-voltage or low-voltage detection

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