A vehicle insulation detection circuit and method

Abstract

The invention provides a vehicle insulation detection circuit and method. The vehicle insulation detection circuit comprises a ground end connected to the ground wire of a vehicle; a first detection circuit connected to the positive electrode of a power battery, connected to ground via the ground end, and provided therein with a first energy storage element connected between the positive electrodeand the ground end; and a second detection circuit connected to the negative electrode of the power battery, connected to ground via the ground end, provided therein with a second energy storage element connected between the negative electrode and the ground end. According to the embodiments of the present invention, the energy storage elements are disposed in the first detection circuit and thesecond detection circuit so that the total voltage can be kept stable during voltage measurement. When a bridge arm is closed, an artificial decrease in insulation resistance can be avoided during a test.

Description

technical field [0001] The invention relates to the technical field of circuit design, in particular to a vehicle insulation detection circuit and method. Background technique [0002] Battery design is the key to restricting the development of electric vehicles, and the insulation of batteries to ground is the main factor affecting the safety of electric vehicles. The insulation performance of the battery is not only related to the normal operation of the vehicle system and electronic equipment, but more importantly, it is related to the safety of the driver's life and property. [0003] How to accurately detect the insulation resistance of electric vehicle power batteries in real time is of great significance for improving the safety of electric vehicles. Therefore, considering the reliability and safety of electric vehicles, it is of great significance to study the insulation monitoring and automatic diagnosis of the high-voltage system of pure electric vehicles. In rel...

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Problems solved by technology

[0004] However, the injection of AC signals in the signal injection method not only increases the ripple coefficient of the DC power supply system and affects the quality of power supply, but also the AC signal is affected by the distributed capacitance of the circuit, and the final detection accuracy is not high.

In the active insulation resistance detection method, the instantaneous high voltage has a great impact on the circuit, the circuit structure is complex, and there are also problems with the stability of the PWM (Pulse Width Modulation, Pulse Width Modulation) wave.

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