Identification method for lumped thermal parameters of lithium ion battery

Abstract

The invention discloses an identification method for lumped thermal parameters of a lithium ion battery. The identification method for the lumped thermal parameters is based on an lumped thermal equivalent circuit and special signal stimulation and by combination with a mathematical algorithm; according to the method, temperature rise of the battery is simulated based on the lumped thermal equivalent circuit; a thermal time constant in the environment is obtained by a temperature change experiment; a functional relation between impedance and temperature is established according to impedance at different temperatures; and by applying sine alternating current with single frequency and amplitude, relatively high accuracy of a battery thermal model is ensured; according to a battery temperature rise model and the functional relation between impedance and temperature, temperature change of the battery under special stimulation is circulated; and an actually-tested battery temperature is approached through a search iterative algorithm, so as to identify specific heat capacity and heat resistance of the battery. According to the method, complex test equipment, such as a heat insulating calorimeter, an isothermal calorimeter and other expensive thermal test equipment are not needed; and in addition, the method has the advantages of simplicity and reliability in identifying thermal parameters of the lithium ion battery, easy realization of engineering and the like.

Description

Technical field [0001] The invention relates to the technical field of battery thermal parameter measurement, in particular to a method for identifying the lumped thermal parameters of a lithium ion battery, especially a method for measuring the lumped thermal parameters of a lithium ion battery by combining sinusoidal current heating and air cooling. Background technique [0002] The dual pressure of energy shortage and environmental pollution has boosted the rapid development of electric vehicles. Lithium-ion batteries (lithium batteries) have the advantages of high cell voltage, high energy density, long life, no memory effect and no pollution, and become the power of electric vehicles. The battery of choice for drive. [0003] The accurate identification of thermal parameters of lithium-ion batteries is the key to battery thermal management. The existing thermal parameter identification methods generally rely on thermal testing equipment such as calorimeters, such as adiabatic ...

AI Technical Summary

Problems solved by technology

[0006] In view of the defects existing in the prior art, the purpose of the present invention is to provide a method for identifying lumped thermal parameters of lithium-ion batteries, which can improve the specific heat capacity test in the prior art, which relies on expensive equipment, is difficult to test online, and is difficult to accurately estimate thermal conductivity. question

Images