Method and system for predicting insulation resistor fault of electric car

Abstract

The invention discloses a method and system for predicting an insulation resistor fault of an electric car, and the method comprises the steps: building the system through employing a synchronous voltage sampling circuit, a control unit, a whole vehicle controller, a first bias resistor, a second bias resistor, an electronic switch K1, and an electronic switch K2; measuring a nominal voltage of a serial battery pack of the electric car and the nominal voltages of all cell modules; and calculating the equivalent parallel insulation resistance and the equivalent voltage source voltage of the system. The resistance values of all cell modules in the serial battery pack of the electric car are compared with the equivalent parallel insulation resistance, thereby achieving the on-line diagnosis of an insulation fault and the on-line positioning of the insulation fault. A plurality of equivalent parallel insulation resistance values of the system at different moments are calculated, and a curvilinear equation of time change with the equivalent parallel insulation resistance values is fitted, thereby achieving the prediction of occurrence remaining time of insulation faults of all stages.

Description

technical field [0001] The invention relates to the field of fault diagnosis, in particular to a method and system for predicting insulation resistance faults of electric vehicles. Background technique [0002] Electric vehicles have become the focus and focus of global development. In order to meet the demand for high-power electric drives, electric vehicles generally use high-voltage DC power supplies. High-voltage safety has become the key technology that needs to be solved first in the application of electric vehicles, which has a very important impact on the safety of the vehicle itself, the safety of drivers and passengers, and the safety of the vehicle operating environment. Among them, insulation fault is an important content of electric vehicle high voltage safety management. However, the existing electric vehicle high-voltage safety management system has the problem of lack of functionality to realize the prediction and location of insulation faults. Generally, ...

AI Technical Summary

Problems solved by technology

Its disadvantage is that it cannot locate the insulation fault, nor can it predict the insulation fault that will occur but has not yet occurred

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