A method for online detection of multiple faults in a power battery pack

Abstract

The invention discloses an on-line detection method for multiple faults of a power battery pack. In a battery pack composed of n battery cells or parallel modules connected in series, 2n voltage sensors are used to cross-measure the voltage to obtain and collect voltage signals; Diagnose whether there is a sensor failure and a contact point failure. After confirming that there is no sensor failure or contact point failure in the battery system, determine whether the battery itself has a short circuit or overcharge / discharge failure. The present invention can be easily grafted with other fault diagnosis methods such as battery short circuit, overcharge / discharge, etc. The present invention can eliminate voltage measurement problems and contact point resistance problems, ensure the accuracy of input, and increase the accuracy of fault diagnosis results sex.

Description

technical field [0001] The invention relates to an on-line detection method for multiple faults of a power battery pack. Background technique [0002] Lithium-ion batteries have the characteristics of high energy density and high power density, so they have been widely used in electric vehicles. The battery management system (Battery Management System, BMS) is the "brain" of the power battery system, which manages hundreds of A battery pack composed of thousands of battery cells, but at the system level, the power battery system still has many potential defects, the first of which is safety issues, and advanced fault diagnosis technology is the core guarantee to ensure the safe operation of the power battery system and the reliable operation of BMS . The fault types of lithium-ion batteries mainly include: sensor faults (measurement faults), battery faults (abnormal internal resistance, overvoltage, undervoltage, overcurrent), contact resistance faults (contact point faults...

AI Technical Summary

Problems solved by technology

[0007] In order to solve the above problems, the present invention proposes a multi-fault online detection method for a power battery pack. The present invention can solve the problem of fast and accurate diagnosis of different fault types and fault points existing in the battery, wherein the measurement circuit is designed through cross-type voltage measurement, And use the corresponding fault diagnosis method to identify the types and fault points of various faults (battery self fault, sensor fault, contact point fault), realize the redundancy of the battery voltage signal, ensure the reliability of the voltage signal, and realize the contact point The detection of resistance voltage division can effectively identify connection point faults and sensor faults. After eliminating sensor faults and connection point faults, other self-faults of the battery can be further diagnosed through the obtained battery measurement parameters.

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