Research On PWM Rectifier Based On The Space Voltage Vector

With the development of power electronics, people has realized that the rectifying system with lower power factor can bring harmonic pollution and induce the power line problem, and therefore it is necessary to improve the power factor for the rectifying system. PWM rectifier is the basic solution of harmonic pollution, because it has no harmonic influence on the power line.For the general inverter, when the motor speed is reducing or the motor is braking, the DC pump voltage is usually consumed by the method of dynamic braking, because the energy can't flow bidirectionally through diode rectifier. However, the dynamic braking has many limitations. PWM rectifier can make the regenerating energy flow into the power line, which extends the applied field of inverter.The mathematical model, working principle and cunent converting mode of PWM rectifier are analyzed in detail in this paper when the power line is balanced. The design method of three-phase inductor and DC capacitor is studied, and the self-adaptive PI regulator is disigned. The constant-frequency PWM control scheme with two-phase modulation, based on space vectors, is proposed. The validity of the control scheme is verified by the experiments with TMS320LF2407A DSP.Besides, A novel two-arm three-level neutral-point-clamped switching mode PWM rectifier is proposed, the mathematical model and the working mode of the rectifier are derived, and the constant-frequency PWM control method is analyzed in detail. The validity of the novel PWM rectifier and its control scheme is verified by simulation with PSIM and MATLAB, respectively.