A rapid detection method for body insulation

Abstract

The invention discloses a quick detection circuit and method for body insulation, which detects the voltage at both ends of a first capacitor, and after the first capacitor is fully discharged, closes the first switch to detect the voltage at both ends of the first resistor, and calculates the current passing through the first resistor, Calculate the voltage across the fourth resistor, the parallel resistance of the third resistor, the fifth resistor, and the fourth resistor; when the voltage value of the first resistor is less than the set voltage value, close the second switch and retest the first resistor Calculate the voltage at both ends of the first resistor and the voltage at both ends of the fourth resistor, and calculate the parallel resistance value of the fourth resistor and the fifth resistor; when the parallel resistance value exceeds the set resistance value, the first relay switch and the second relay switch The electric switch is allowed to be closed; when the parallel resistance value does not exceed the set resistance value, the first relay switch and the second relay switch are prohibited from being closed; Safety accidents caused by leakage of internal electrical components.

Description

technical field [0001] The invention relates to the field of insulation detection, in particular to a rapid detection method for vehicle body insulation. Background technique [0002] An electric vehicle is a mechatronic product, and its power battery, motor, auxiliary charging device and other components need to consider high-voltage insulation issues. At the same time, the environmental conditions used by electric vehicles are relatively harsh, such as high-intensity bumps and vibrations, acid-base gas corrosion, and large temperature changes. In such an environment, the insulation materials of electric vehicle components will age or even be damaged, resulting in leakage. The voltage value of the power battery pack of an electric vehicle is above 300 volts, far exceeding the human body safety voltage of 36 volts, so once a leakage occurs and cannot be detected in time, it will cause life danger to the driver or passengers. Insulation detection mainly judges the insulation...

AI Technical Summary

Problems solved by technology

At the same time, the environmental conditions used by electric vehicles are relatively harsh, such as high-intensity bumps and vibrations, acid-base gas corrosion, and large temperature changes. In such an environment, the insulation materials of electric vehicle components will be aged or even damaged, resulting in leakage.

The voltage value of the power battery pack of an electric vehicle is above 300 volts, far exceeding the human body safety voltage of 36 volts, so once a leakage occurs and cannot be detected in time, it will cause life danger to the driver or passengers

Insulation detection mainly judges the insulation by detecting the insulation resistance of the object to be tested. The existing insulation resistance measurement methods include: AC signal injection method and unbalanced bridge method; the AC signal injection method is affected by the load of the power battery in the electric vehicle. Affected by the instability of the load after the power battery works, the measurement of the AC signal injection method is inaccurate; the measurement method of the unbalanced bridge needs to set up a high-voltage circuit to pressurize the component to be measured.

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