| Global energy shortages and environmental pollution are becoming increasingly fierce.Various countries in the world are actively seeking solutions to these two major crises.The rapid expansion of the traditional fuel vehicle is one of the major causes.Electric Vehicles(EVs)use electricity as energy source and can achieve low or even zero emission of exhaust gas.The replacement of traditional fuel vehicles by EVs is a key approach to solve the above problems.Power batteries who provide energy are the core components of EVs.The rapid development of the battery industry puts forward higher requirements on the quality and quantity of power batteries.Whether it is to develop better batteries or better use of batteries,battery testing occupies a pivotal position.Looking at battery test equipment at home and abroad,the main high-precision products are monopolized by foreign leading companies.The domestic battery testing industry started late,and the test equipment technology is backward.In particular,the power battery data acquisition equipment is far from the international leading level.Aiming at the problems of slow acquisition speed,low precision and poor synchronization in current power battery data acquisition equipments,this paper has designed and developed a set of power battery high-precision data synchronization acquisition system.The main works of this thesis are listed as follows:(1)The functional requirements of the system are analyzed and the ideas of system construction are expound.The system is divided into several modules according to its function.The structure of the hardware and the framework of the software are designed.(2)Hardware implementation circuits for each functional module of the system are designed,including cell voltage acquisition,cell temperature acquisition,battery voltage acquisition,battery current acquisition and data communication.The working principle,functional structure and device selection of each circuit are introduced in detail.In order to increase the system's accuracy and precision,each module uses high-precision sensor,high precision low temperature-drift devices,24-bit high-resolution analog-to-digital converters(ADCs),and analog filter circuits.The Field-Programmable Gate Array(FPGA)is used as the controller and a parallel real-time control system architecture is built to achieve the system working in parallel.Functional simulation of critical circuits is performed to ensure the effectiveness of the design.(3)A variety of digital filters are researched to filter out noise in the acquired data.According to the principle of each digital filter,the MATLAB program is programmed to process sampling result data,and the obtained filtering result is analyzed.An adaptive Kalman filter is designed to achieve the output signal reflects the battery state more faithfully.After that,various filters are compared around the filter performance and the difficulty of FPGA implementation.(4)Based on the design of the hardware circuit,the control software is designed.According to each module's features,their software flows are designed.FPGA implementation of digital filters is completed.(5)In order to verify the validity of the high-precision data acquisition system designed in this paper,an experimental platform is built and experiments including battery cell voltage acquisition,cell temperature acquisition,battery voltage acquisition and battery current acquisition are done.The experimental results show that the system designed in this paper can fully realize the expected functions and have excellent performance.The power battery high-precision data acquisition system designed in this paper has the advantages of modular scalability,fast sampling speed,high precision and accuracy and strict sampling synchronization.The system is advanced,practical,and has significant scientific merit.It can be widely used in various tests of the power battery.It is of great significance to promote the development of the power battery test industry... |
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