Detection method of electric automobile insulating performance

Abstract

The invention relates to a detection method of electric automobile insulating performance. According to the method, a relay 1 and a relay 2 are employed to connect with an anode and a cathode of a direct current bus respectively, voltage division resistors R1 and R1' are in series connection between the relay 1 and a ground (i.e. automobile body), voltage division resistors R2 and R2' are in series connection between the relay 2 and the ground, direct current source 1 injects a direct current signal to a circuit through a diode d1 and a resistor R3, and a direct current source 2 injects a direct current signal to the circuit through a diode D2 and a resistor R4. Four voltage sampling circuits are provided on the R1', R2', R3 and R4 resistors respectively. Through combining the above circuit with specific sampling and calculating steps, insulating performance detection is realized. According to the invention, a method of injecting direct current by a power source is employed to carry out detection, detection precision is high, resistance of the voltage division resistors can be selected to be a large value, influence on vehicle insulating performance in measurement is small, and normal working of an original vehicle system is not interfered.

Description

technical field [0001] The invention relates to the technical field of electric vehicles, in particular to a method for detecting the insulation performance of electric vehicles. Background technique [0002] Out of energy and environmental considerations, electric vehicles have been rapidly developed due to their energy saving and environmental protection. In order to achieve a certain voltage level, multiple batteries are often used in series in electric vehicles, and the voltage range is between 300-500V. In the actual operation of electric vehicles, the working environment is relatively complex, vibration and wear, changes in temperature and humidity, liquid corrosion and other reasons will cause the decline in insulation performance and endanger the personal safety of people in the car. Therefore, insulation detection technology is an important technology related to personal safety of electric vehicles. [0003] At present, insulation measurement methods are mainly di...

AI Technical Summary

Problems solved by technology

The disadvantage of this method is that the detection system requires high precision, and the resistance value of the resistance connected in series to the detection system should not be too large, otherwise the measurement accuracy will be affected

Due to the small resistance value, the series connected resistor itself reduces the insulation performance of the electric vehicle

In addition, when the insulation performance of the positive and negative busbars is reduced at the same time, this method cannot be detected.

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