Studies of Electric-drive Control System for the Two-wheel Electric Vehicle

　　Studies of Electric-drive Control System for the Two-wheel Electric Vehicle
　　Aiming at the Rare Earth Permanent Magnetic (REPM) brushless synchronous motor (SM) of a two-wheel electric vehicle, two kinds of control technologies are studied separately under sine-wave and square-wave working modes. Based on a comprehensive analysis of the working principle, speed regulating control method and characteristics of the sine-wave and square-wave brushless motors, the drive system construction and control circuit design of both a Block Ceramic Magnets 36VDC electric bicycle and a 96VDC electric motorcycle are proposed in this paper.In this paper special integrated intelligent chipsets together with cheap EEPROM are chosen as the core control unit, and steady SPWM pulse signals can be derived to construct a 36VDC sine-wave drive system through this technology. The peripheral circuit is simple and concise in comparison with analog system; it can also prevent the unsteady situation of traditional SPWM signal generating method through microprocessor program. Besides, special PWM regulating chipsets and logic hardware elements are used to construct a 96VDC square-wave drive system, which adopts a wide-range input voltage switch power supply to provide power supply to the system, and brings negative off-current feedback into the brushless motor drive system, in this way the reliability of a high-power square-wave drive system can be improved, and the prototype system is steady with a 30A load current at most.Through comparison of the above two system test results, it can be concluded that: for brushless REPM synchronous motors with the same structure, both sine-wave drive system control technology and square-wave drive system technology have advantages and disadvantages at the same time. Sine-wave drive system adopts variable frequency http://www.chinamagnets.biz/Ceramic/Block-Ceramic-Magnets.php speed regulating method, thus the motor is steady, and when weak magnetic speed regulating method is used, the motor can also operate with very high speed and constant power, but it’s prone to out-of-step; While the square-wave drive system adopts PWM voltage regulating and speed regulating method, thus the motor has better control characteristics, harder mechanical characteristics and a bigger startup torque. The vehicle can speed up very quickly,