Nonlinear cooling optimization method for power battery of new energy automobile

Abstract

The invention provides a nonlinear cooling optimization method for a power battery of a new energy automobile. Firstly, a lithium ion battery concentrated mass thermal model under a new energy automobile liquid cooling condition is established, and the model considers the change of battery internal resistance along with temperature and the change of a heat transfer coefficient along with the flowrate of cooling liquid, so that the requirement on battery temperature influence factor analysis in the cooling process can be met; secondly, a nonlinear cooling optimization strategy which comprisesthe design of a steady-state control law, the design of a reference variable feedforward control law and the design of an error feedback control law is proposed. The method guarantees the accuracy ofthe model, facilitates the research of the overall performance of the lithium ion battery and related influence factors, guarantees the steady-state closed-loop performance of the system, facilitatesthe enlargement of the engineering application range of the controller, can effectively adjust the temperature of the battery, prevents thermal runaway, and guarantees the safety of the power batteryof the electric vehicle.

Description

technical field [0001] The invention relates to the technical field of new energy vehicle batteries, in particular to a nonlinear cooling optimization method for new energy vehicle power batteries. Background technique [0002] With the development of society, the problems of energy shortage and environmental pollution have become more and more serious. New energy vehicles have gradually become the mainstream of the future development of the automobile industry because of their clean and efficient characteristics. Power battery is the core component of new energy vehicles. With the continuous improvement of people's requirements for the mileage of new energy vehicles, its energy density is also increasing. During the charging and discharging process of high current, the power battery of the car will accumulate a lot of heat. If If the heat is not dissipated in time, the temperature of the battery will increase sharply, and the capacity and cycle life of the battery will also...

AI Technical Summary

Problems solved by technology

This kind of hysteresis adjustment is a typical switch adjustment. It uses a fixed coolant flow rate to dissipate heat for the battery. It cannot adjust the coolant flow rate according to the actual heat dissipation requirements of the battery. Excessive heat dissipation, resulting in energy waste, and frequent opening and closing of the cooling device is likely to cause damage to the cooling device

In the process of adjusting the cooling of the battery by the finite state machine and PID, its parameters must be continuously adjusted, relying on expert experience, and the optimization effect is far from being achieved without experience, especially in electric vehicle power batteries. It is difficult to obtain empirical rules

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