Research On Battery Parameter Measurement System Based On Synchronous Sampling

With the rapid development of social economy and science and technology,the concept of low carbon has been deeply rooted in the hearts of the people.Power batteries,due to their applications in electric vehicles,urban rail transit and energy storage,have attracted more and more attention and gradually become the research focus of the modern era.The widespread application of power battery makes the demand of power battery surge.After mass production of power batteries is completed,the battery needs to be tested before leaving the factory.It is required that the output voltage,current,battery capacity,SOC status and battery parameters of the power battery can be accurately measured.In this thesis,a power battery parameter measurement system is designed for the test of power battery.This thesis,by introducing several common equivalent circuit models,and according to the daily battery research needs of the parameters,have designed a power battery parameter measurement system,detailed introduction of the system’s overall flow and function.By comparing the existing sampling measurement device,to achieve power battery parameters measurement,this thesis designed the high accuracy multi-channel synchronous measurement device.The synchronous measuring device can synchronously measure the multi-channel voltage signal;current signal and the ampere-hour integral data of the measured current in this period with high precision,controls the charge-discharge machine through CPU;communicate with other devices at high speed through Ethernet,including the transmission of measurement data through Ethernet and the demand of receiving the client written by the upper computer;controlled the charge-discharge machine by CAN communication.This thesis introduces the overall design,hardware circuit design and software design of the measuring device in detail.In this thesis,the synchronous sampling device is tested systematically by using the static and then dynamic testing method.Through testing,it is verified that the measurement of voltage,current and current ampere-hour integral data of the power battery by the synchronous sampling device can meet the requirements of precision and frequency.The SOC state of the power battery can be estimated by the ampere-hour integral results obtained by measurement.Through the experiment of corresponding working conditions,the relationship between the OCV-SOC of the power battery was measured.Through the recursive least square method with forgetting factor and MATLAB simulation to carry out online parameter identification simulation,the feasibility of this method is verified.This thesis introduced the process of realizing the designed function of the power battery parameter measurement system.