The Research On Drive And Charging Device For Electric Vehicle

Facing the increasingly serious energy crisis, environment pollution, climate change, vigorously develop to electric Vehicle, as a representative of the new energy vehicles, is our country realize the energy strategic transformation of social and economic sustainable development. Choose high performance, high efficiency of the motor and its drive system and how to realize the electric vehicle is fast charging electric vehicle of rapid promotion effect two important aspects. Relative to the vector control, direct torque control in its structure, reliability and dynamic and static performance are many advantages, plus the permanent magnet synchronous motor torque motor with high efficiency, high density, overload ability strong, small volume, light quality, power densities etc, and so will direct torque control used in electric vehicle with permanent magnet synchronous motor for electric vehicle electric drive technology development to have the important meaning.This paper first to permanent magnet synchronous motor as electric Vehicle drive motor, established the mathematical model of permanent magnet synchronous motor, and calculates the stator voltage and magnetic flux equations, torque equation and motion equation. On the basis of the permanent magnet synchronous motor further analysis of direct torque control strategy. In the traditional way of existing in the control of magnetic chain, the torque ripple of the defect, this paper will space vector pulse width modulation (SVPWM) technology into the permanent magnet synchronous motor of the direct torque control system, and achieving the stator flux vector modulation and the precision of the smooth electromagnetic torque control. On paper, the mathematical model and direct torque control of basic theory analysis, construction of these two kinds of direct torque control corresponding control structure diagram, and the corresponding simulation.This paper mainly is the third chapter electric vehicle electric drive system hardware design of the control system are presented and the software flow chart.To solve the problem of the electric vehicle fast charging, this paper designs a voltage source PWM rectifier based on three-phase and reversible DC/DC converter the reversible charging pile. PWM converter can realize unit power factor, energy two-way flow and output voltage. The electric vehicle in charge is equivalent to load, PWM converter working in rectifying state, control the voltage current net side waveform phase and the sine wave, power factor for1, the output voltage stability, DC/DC converter working in buck chopped mode, then absorbs energy from the power grid storage battery; Electric Vehicle as energy storage unit connection with power grid, three-phase VSR work in inverter, and keep the inverter output voltage and current of the grid synchronous, DC/DC converter working in boost the chopper mode, then the battery back to send energy PWM converter DC side, again through the PWM rectifier feedback power grid.The end of the article on the experimental study of PWM converter is presented, and the end, the results show that the system realized the unit power factor, the output voltage stability.