Multi-time-scale short-circuit resistance estimation method for series battery pack

Abstract

The invention discloses a multi-time-scale short-circuit resistance estimation method for a series battery pack. According to the method, a multi-time-scale short-circuit resistance estimation conceptis proposed for the first time, the concept comprises a short-time-scale estimation part and a long-time-scale estimation part which are used for obtaining a hard short-circuit resistance value and asoft short-circuit resistance value respectively, and quantitative diagnosis of two types of short-circuit faults of a hard short circuit and a soft short circuit is achieved at the same time. The method specifically comprises the following steps: measuring and acquiring voltage and current measured values of a battery; performing short-time-scale short-circuit resistance estimation, estimating ahard short-circuit resistance value, and converting the hard short-circuit resistance value to long-time scale estimation when a scale conversion condition is met; and performing long-time scale short-circuit resistance estimation, and estimating a soft short-circuit resistance value. Therefore, the real-time diagnosis capability of the battery management system is further improved. According tothe method, only the single battery with the highest voltage and the single battery with the lowest voltage in the series battery pack are selected for analysis, calculation complexity is greatly reduced, practical application is easy, and the method has important significance in battery pack short-circuit resistance estimation and fault diagnosis.

Description

technical field [0001] The invention belongs to the technical field of battery fault diagnosis and estimation, and relates to a multi-time-scale short-circuit resistance estimation method of series battery packs. Background technique [0002] The battery management system (BMS, Battery Management System) is considered to be one of the most important components in electric vehicles and mobile robots. Its function is to ensure that the battery is in proper working condition and prolong its service life. The first priority of battery applications should be safety. To ensure safety, it is necessary to monitor or estimate the battery state, corresponding battery state of charge (SOC, State of Charge) estimation, health state estimation, battery balancing, inconsistency, etc. have been extensively studied. With the development of electric vehicles and mobile robotics, high-energy-density batteries are required to extend the driving range. When the energy density continues to inc...

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Problems solved by technology

[0005] Although the diagnostic effect of the above method is generally good, the existing method fails to realize the joint estimation of hard short circuit and soft short circuit resistance, and when the two short circuits occur at different positions of the battery pack, effective positioning and diagnosis cannot be achieved.

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