Electric automobile power battery major loop circuit relay failure detection circuit and method

Abstract

The invention puts forward an electric automobile power battery major loop circuit relay failure detection circuit and method. The circuit comprises a whole vehicle interface circuit, a normally close low voltage relay, a current-limiting resistor, a high voltage optical coupler, a voltage dividing resistor, an isolating amplifier and a power source module, wherein one end of a contact point of the normally close low voltage relay is connected with an anode of a low voltage storage battery while the other end of contact point of the normally close low voltage relay is connected with a control end of the high voltage optical coupler via the current-limiting resistor, and one end of a low voltage relay wire coil is connected with an ACC gear power source while the other end is connected with a cathode of the low voltage storage battery; electricity is supplied to the isolating amplifier and the power source module via the low voltage storage battery, and two ends of a voltage dividing resistor circuit are respectively connected onto a downstream part of a main positive contactor contact point and an upstream part of a main negative contactor contact point. The electric automobile power battery major loop circuit relay failure detection circuit and method are simple in wire connection, convenience of whole vehicle arrangement can be realized, and main positive and negative contactor adhesion faults of a power battery can be detected off-line in a low power consumption and high reliability manner. After the whole vehicle is powered on, the detection circuit is invalidated, and effects exerted on other detection methods can be reduced.

Description

technical field [0001] The invention relates to the field of electric vehicles, in particular to a power battery main circuit relay fault detection circuit and a detection method of the electric vehicle. Background technique [0002] The power battery is the power source of electric vehicles and has certain online fault detection functions. The main positive contactor and the main negative contactor of the power battery realize the high-voltage power supply of the power battery to the motor and other auxiliary machines. The high-voltage circuit cannot be disconnected, and the power battery will continue to discharge through the motor controller. After the power battery is powered off, the fault detection cannot be realized. If the fault cannot be detected by a certain detection device and the relevant personnel are notified in time to deal with it, it may cause severe power feeding to the power battery and cause damage to the power battery. At the same time, due to the adh...

AI Technical Summary

Problems solved by technology

However, in the process of power off after parking, that is, when the key is from ON→ACC→OFF, the driver will generally power off quickly, so that the fault prompt issued by the fault detection device of the whole vehicle cannot be found.

Images