Design Of Hall Current Sensor For Electric Vehicle Application

Current detection is an important function of power control unit of electric vehicles.And its performance is directly related to the stability and reliability of electric vehicles.The current detection method based on series resistance has some shortcomings,such as high power loss,temperature drift affecting accuracy and isolation difficulty,which limits the further improvement of electric performance of electric vehicles.In contrast,the current detection method based on Hall current sensor has the advantages of low loss,stable performance,self-isolation and strong overload ability,and has gradually become the mainstream current detection method in electric vehicles.Firstly,the working principle of Hall current sensor is analyzed,and the main factors affecting the key performance of Hall current sensor are studied in depth.The response time of the core is modeled and analyzed.According to the model,the core's response time is predicted to be 0.9~2.4?s.Secondly,the design of Hall current sensor is completed.Hall integrated circuit A1363 and MLX91209 which can meet the electrical performance requirements are selected.The material of magnetic core was studied and the core was made of silicon steel 23JGSD085.The influence of core geometry is analyzed in detail and verified by finite element simulation.The size of air gap is 5mm,cross-sectional area is 5×8 mm~2 and window area is 23×9 mm~2 in the case of measuring range800A.The structure materials of Hall current sensor are compared and PA66-GF30 is chosen as the structure material.By using DFMA(design for manufacture and assembly)design method,this paper focuses on the detailed design of different structure parts And a new type of magnetic core grounding method is proposed for the electromagnetic compatibility design of Hall current sensor.Then,three experimental platforms are built to test the DC,response and temperature characteristics of Hall current sensor.The test results show that the designed Hall current sensor has good performance with measuring range of 800A,accuracy(±1.0%),linearity(±0.5%)and response time(5.4?s),which can meet the design requirements.Finally,the assembly and testing process of Hall current sensor is analyzed by means of automatic production line.The detailed analysis and design of the position,layout,rhythm and traceability of the automatic production line are emphasized.The results show that the designed automatic production line has a beat time of about 4 minutes and a high balance rate(92.8%).And its traceability system can meet the requirements of product records.