Battery pack high-voltage relay functional response fault diagnosis method and device

Abstract

The invention discloses a battery pack high-voltage relay functional response fault diagnosis method and device. The method includes the following steps that: a pre-charge relay pull-in instruction, apre-charge relay disconnection instruction, a main negative relay pull-in instruction, a pre-charge relay pull-in instruction, a main positive relay pull-in instruction and a pre-charge relay disconnection instruction are sequentially transmitted according to a high-voltage electrification process; after the instructions are transmitted, voltage and / or current parameters are collected; and whether high-voltage relays undergo functional response faults is detected according to the parameter values of the collected voltage and / or current parameters or the change conditions of the parameter values, and the types of the faults are distinguished. With the battery pack high-voltage relay functional response fault diagnosis method and device provided by the technical schemes of the invention adopted, the fault problems of the high-voltage relays in a battery pack can be found in time according to the collected voltage and current parameters. The diagnosis method and device of the inventioncan be applied to the detection of the functional response faults of the high-voltage relays of each battery pack in a vehicle provided with a plurality of battery packs.

Description

technical field [0001] The invention relates to the technical field of power batteries, in particular to a method and device for diagnosing functional responsive faults of high-voltage relays of battery packs. Background technique [0002] The power battery is used as the capacity output circuit of the electric vehicle new energy vehicle, and its energy output is realized by switching on and off multiple high-voltage relays, including the main positive relay, the main negative relay and the pre-charging relay. Usually, the fault behavior that the high-voltage relay cannot correctly respond to the relay pull-in command or the relay disconnection command issued by the battery management system is collectively referred to as the functional response fault of the relay. If one or more of the multiple high-voltage relays has a functional response failure, it will affect the energy output of the power battery, thereby affecting the use of new energy vehicles, and even causing safet...

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Problems solved by technology

[0003] However, in the process of implementing the embodiments of the present invention, the inventors found that there are at least the following problems in the prior art: the prior art cannot realize fault detection for each of multiple high-voltage relays at the same time during the high-voltage power-on process , and it is not possible to accurately determine whether the fault type of each relay is a sticking fault or a stuck fault

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