Device and method for detecting state of main circuit relay in DC power supply system

Abstract

The invention discloses a device and a method for state detection of a main loop relay of a direct-current power supply system. The device comprises current-limiting resistors, disconnecting switches and current detecting circuits, the current-limiting resistors, the disconnecting switches and the current detecting circuits are sequentially connected in series to form detecting branch circuits, and the detecting branch circuits are connected to two ends of a main contact of the main loop relay in a cross manner. The method is used for detecting the state of the main loop relay by the aid of the device for state detection of the main loop relay of the direct-current power supply system. The device is simple in circuit structure, can perform online real-time detection of the state of the main loop relay of the direct-current power supply system, can reliably detect the state of the main loop relay and precisely judges whether the relay is in the normal state or fault state, and thereby power output of a power supply device is well controlled, and personal and equipment safety is guaranteed beneficially.

Description

technical field [0001] The invention relates to a main circuit relay state detection device and method, in particular to a main circuit relay state detection device and method of a DC power supply system. Background technique [0002] With the increasing tension of fossil energy, the application requirements of energy saving and environmental protection are getting more and more attention. Therefore, various efforts to develop pure electric vehicles or hybrid vehicles in recent years are aimed at reducing energy consumption and pollution to the living environment. [0003] At present, the power supply system used in hybrid electric vehicles and pure electric vehicles is usually composed of multiple battery packs in series, and the DC bus voltage is as high as hundreds of volts, which is far beyond the safe voltage that the human body can bear. Once the high-voltage system fails , it is very dangerous for operation or maintenance personnel. The output and shutdown of the hi...

AI Technical Summary

Problems solved by technology

[0004] At present, for relay state detection, it is mainly to collect the current in the relay coil as the basis for whether the relay is working normally, but this method can only detect whether the controller or the battery management system (BMS) controls the relay, and cannot really judge Whether the main contact of the relay is open or closed, it cannot be clearly judged whether the relay is in a normal state or a fault state

For example, in the case of relay main contacts sticking (relay sticking, that is, at the moment of high-voltage contact, the main contacts of the relay generate an arc before contact, and the high-temperature arc burns the contacts, resulting in the phenomenon that the contacts cannot be disconnected normally), The disconnection of the relay is controlled by the main controller CPU of the DC system or the battery management system (BMS), but the controller cannot judge whether the relay is stuck, and the work reliability is poor. The staff often mistakenly think that the relay has disconnected the high-voltage power supply. If the staff At this time, when touching the high-voltage busbar for maintenance or installation, it will cause danger to people or equipment.

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