Study On Induction Motor Drive Controller For Elecrtric Vehicle

With the development of the social economy,environmental pollution and energy crisis are becoming more critical issues.It has been planned that to handle these problems by adopting the development of electric cars as an effective approach.Electric cars have their special requirements for the electric motor and its control system,which have significant research value.Alternate-current(AC)motor control system has been most widely used for its low cost,high reliability and excellent speed regulation.Thus,the researches on AC asynchronous motor control system are of great significance.During the past decade,semiconductor industry has been developed rapidly.Power converters based on power electronic devices have been widely adopted in motor speed regulation systems.By using power electronic inverters,a DC source can be transformed into AC source with variable magnitudes and frequencies,which can be applied to AC motor to achieve speed regulation.Vector control technology is one of the most widely used motor drive technologies.The core of motor is to decouple the stator current into two DC parts by the coordination of transformations to achieve the decoupled control of the flux and torque of a AC motor.Thus,the AC motor can be equivalent to a DC motor during the control design process.This project is based on the space vector pulse width modulation technology,realizing an equivalent sinusoidal voltage supplied to the motor.To tackle the calculation error in traditional flux observers,a voltage and current mixed flux observer model is used in this paper.The control system also applies the decoupling control with improved PI,realization of AC motor with DC control,optimal control parameters and algorithm dynamic regulation are considered to meet the vehicle full range speed regulation requirement.The hardware setup takes TMS320F2808 chip DSP of American TI company as the control core to construct control circuit.The system also includes the power electronic converter,three phase AC motor,sampling circuit and the power supply circuit board.For software design,C language has been emplored to achieve the mixed flux observer model and space vector pulse width modulation to accomplish the purpose of speed control.The simulation and experimental results show that the hardware and software designed are in line with the actual needs and the proposed system has the characteristics of high reliability,small size and high power density.