Method of identifying open-circuit voltage and direct-current internal resistance of battery based on constant current experiment

Abstract

The invention provides a method of identifying open-circuit voltage and direct-current internal resistance of a battery based on constant current experiment, and belongs to the technical field of batteries. The method comprises: performing constant current experiment at different ambient temperatures, performing fitting or interpolation on same working current with SOC (state of charge) and terminal voltage data under different battery temperatures to obtain identification value of the working current relative to the SOC and terminal voltage data under the specified battery temperature by making use of the characteristic that parameters of a direct-current internal resistance model are of continuous monotonous relationship with working current and battery temperature; performing fitting or interpolation on the same SOC with battery temperatures and terminal voltage data of different working currents so as to obtain a terminal voltage and working current relational expression, using the relational expression to identify terminal voltage of a part where the working current is 0, and adding a constant to correct the terminal voltage to obtain open-circuit voltage; using the obtained terminal voltage and the open-circuit data to solve direct-current internal resistance. Compared with traditional methods, the method of the invention has suitable experimental quantity and high identification precision and is more suitable for engineering application.

Description

Technical field [0001] The invention belongs to the technical field of batteries, and in particular relates to a method for identifying open circuit voltage and DC internal resistance of a battery based on a constant current experiment. Background technique [0002] In order to ensure the safe and efficient operation of battery energy storage systems, battery energy storage systems are equipped with battery management systems to manage batteries. In the battery management system, the development of battery model and its parameter identification are the basis for other work and are of great significance. [0003] There are many forms of battery models. Among them, the equivalent circuit model is the most commonly used model in current battery management systems due to its simple structure, easy understanding and online implementation. Among the equivalent circuit models, the DC internal resistance model has the simplest structure and is widely used. The DC internal resistance mode...

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Problems solved by technology

[0031] The purpose of the present invention is to solve the time-consuming problem in the identification method of open circuit voltage E; the problem of inaccurate identification results in the original identification method of DC internal resistance R; the workload of experiments and data processing in the improved identification method of DC internal resistance R is greatly increased and the identification accuracy Issues still to be improved

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