Research On Vehicle BLDCM Control System

Due to the energy security and environmental protection and other reasons, new energy vehicles with little emissions has a wide range of energy sources and energy efficiency advantages. Our country regards new energy automotive industry as a basic national policy. During the 13th Five-Year, the electric drive must be regarded as the core technology to develop, and the electric vehicle power system technology platform must be developed. The new energy automobile industry should realize the industrialization of electric vehicle. Motor and its control system is one of the key components of electric vehicles, becomes one of the hot spots among the world automobile companies and research institutions. BLDCM has the advantages of low production cost, simple production process, high efficiency, high reliability and fast dynamic response characteristics, which has been widely used in the field of new energy vehicles. According to the requirements and characteristics of electric vehicles, this paper designed the control system of BLDCM and studied its different control methods.Firstly, this paper introduced the development status of electric vehicles and vehicle motor, several driving motors of electric vehicles were compared. The electric vehicle BLDCM structure and working principle was introduced and the mathematical model was established. The motor position detection technology, Two-Two conduction control strategy, vector control and field weakening control were elaborated, which were the bases of the motor control system hardware designing and software control strategies developing.Secondly, in the aspect of hardware designing, this paper introduced the process of drawing control board circuitry using Cadence software.32-bit Infineon automotive processor was used as the main control chip, the output PWM drive circuitry, rotating drive circuitry, power supplying circuitry and CAN bus communication circuitry were drew. In addition, the overcurrent, over temperature and overvoltage alarm circuitry were also added. In the aspect of software designing, according to the characteristics of AUTOSAR software architecture, the software control system with the function of protecting was developed, the two-two conduction mode and neural network control strategy were adopted.Finally, on the experimental platform of D&V power dynamometer, the test bench of the BLDCM control system was set up. The control interface of BLDCM system was developed by using VB language. According to the test results, PWM_ON_PWM had better control effect than H_PWM_L_PWM, and the vector control was better than the two methods. Under the same conditions, the constant power Flux-Weakening control test data showed that the control effect of vector control method was better than the current lead angle method, the torque was more stable, but the output torque was smaller. It also proved that the developed BLDCM control system in this paper had high reliability.