Diagnosis system and method for electric vehicle battery pack insulation resistance detection circuit

Abstract

The invention provides a diagnosis system and method for an electric vehicle battery pack insulation resistance detection circuit. According to the diagnosis system and method, a first known measuringresistor and a third known measuring resistor are connected in parallel with the insulation resistor of the positive pole terminal of a battery pack; a second known measuring resistor and a fourth known measuring resistor are connected in parallel with the insulation resistor of the negative pole terminal of the battery pack; a first switch is connected in series with the first known measuring resistor; a second switch is connected in series with the second known measuring resistor; a third switch is connected in series with the third known measuring resistor; a fourth switch is connected inseries with the fourth known measuring resistor; a fifth known measuring resistor is connected in parallel with the insulation resistor of the positive pole terminal of the battery pack; a fifth switch is connected in series with the fifth known measuring resistor; a sixth known measuring resistor is connected in parallel with the insulation resistor of the negative pole terminal of the battery pack; and a sixth switch is connected in series with the sixth known measuring resistor. The diagnosis system and method of the invention can perform diagnosis when the insulation detection circuit fails, and can improve the reliability of insulation data.

Description

technical field [0001] The invention relates to the technical field of automobiles, and more particularly, to a diagnosis system and method for an electric vehicle battery pack insulation resistance detection circuit. Background technique [0002] Energy shortages, oil crises and environmental pollution are intensifying, which have a huge impact on people's lives and are directly related to the sustainable development of the country's economy and society. All countries in the world are actively developing new energy technologies. As a new energy vehicle with reduced oil consumption, low pollution, and low noise, electric vehicles are considered to be an important way to solve the energy crisis and environmental degradation. Hybrid vehicles take into account the advantages of pure electric vehicles and traditional internal combustion engine vehicles at the same time. On the premise of meeting the requirements of vehicle power and mileage, it effectively improves fuel economy...

AI Technical Summary

Problems solved by technology

The structure of the active detection circuit is complex, the cost is high, and the development is difficult. More and more solutions use the passive method to perform insulation detection.

However, when the battery high-voltage system has a large parasitic capacitance to the car body, due to the charging and discharging effect of the capacitance, the passive method detection circuit cannot accurately and effectively measure the insulation resistance value

[0004] The insulation detection method commonly used at present does not have a self-diagnosis function. When the insulation detection circuit itself fails, the fault information cannot be obtained, and the reliability of the insulation data cannot be judged in time.

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