Lithium ion power battery safety degree estimation method and estimation device based on adaptive Kalman filtering

Abstract

The invention discloses a lithium ion power battery safety degree estimation method and an estimation device based on adaptive Kalman filtering, and belongs to the technical field of battery safety degree estimation. The invention aims to solve the problem that the safety of the power battery cannot be quantitatively expressed and evaluated in the prior art. The method comprises the steps of constructing an equivalent model of a battery; acquiring load current and load voltage of the battery, obtaining polarization voltage and internal electromotive force of the lithium battery of the equivalent model through the equivalent model, and obtaining an SOC percentage maximum value and optimal voltage through adaptive Kalman filtering; acquiring the temperature of the battery, and performing Kalman filtering on the temperature to obtain a temperature estimated value; subjecting the optimal battery SOC, the optimal voltage and the temperature estimation value to fuzzy control to generate thebattery safety degree; according to the invention, quantitative real-time representation of the battery safety degree is realized.

Description

technical field [0001] The invention relates to the field of battery safety degree estimation, in particular to a lithium-ion power battery safety degree estimation method and estimation device based on an adaptive Kalman filter. Background technique [0002] With the acceleration of the commercialization of electric vehicles in the global market, the demand for high-power and high-energy power batteries has increased rapidly, and the safety of batteries has attracted more and more attention. Especially in recent years, news of accidents such as spontaneous combustion and explosion of lithium batteries have occurred from time to time, and the safety of lithium batteries has received more and more attention. At present, my country's lithium battery is still in the initial stage of technology research and development, and there are still many problems in terms of safety. [0003] Safety accidents come from thermal runaway, and there are two main causes of thermal runaway, one...

AI Technical Summary

Problems solved by technology

[0003] Safety accidents come from thermal runaway, and there are two main causes of thermal runaway, one is mechanical and electrical causes (caused by accidents such as acupuncture and collisions), and the other is electrochemical causes (overcharge, fast charge, spontaneous short circuit, etc.) , the thermal runaway of the battery cell is transmitted to the adjacent cells, and then spreads over a large area, eventually leading to safety accidents

The development of thermal runaway also has a certain stage. According to relevant data, the initial temperature of SEI film decomposition is about 100 degrees Celsius to 130 degrees Celsius. This temperature is also regarded as the starting point of a series of thermal runaway temperatures, and the temperature reaches 300 degrees Celsius. When the temperature of the battery reaches the peak, the temperature of the battery will rise sharply. If no corresponding safety measures are taken, there is no doubt that the battery will cause irreparable damage to the user when the temperature reaches the peak.

However, how to achieve real-time and accurate safety estimation has always been a bottleneck problem in the design process of lithium-ion power battery packs.

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