Research Of Three-phase Voltage Source PWM Rectifier Based On Voltage Space Vector Control

Traditional diodes uncontrollable rectifiers and SCR phase-controlled rectifiers could bring harmonic current pollution into the grid, and deteriorate the power factor of system. PWM rectifiers replace the semi-controlled and non-controlled switches with full-controlled ones such as MOSFET and IGBT, which are controlled by pulse width modulation (PWM) technology. PWM rectifiers could run in four quadrant, and make the grid-side current sinusoidal, accordingly realize "green power conversion".At first, the working principles of three phase voltage source rectifier was analyzed, and then its mathematical model in synchronous rotating d-q coordinate system was set up by coordinate transformation. Through the comparison of several different control strategies, concerning the performance requirements of the system, active and reactive current double closed loop control strategy based on instantaneous reactive power theory was selected with the grid voltage orientation. Digital PI adjustor was designed. Inductor on AC side and capacitor on DC side were also designed according to the dynamic and stable performance of the three phase voltage source rectifier.In the thesis, the principle of space vector pulse width modulation was described. A simplified SVPWM algorithm was proposed, which directly calculated the position of reference voltage vector and operation time of space voltage vectors in various sectors according to the components of reference voltage vector in the two-phase stationary coordinate system. The simulation model was established in MATLAB/SIMULINK environment, by which the dynamic and stable performance of the system were emulated and analyzed. Simulation results indicated that the system could run under unity power factor and the energy could flow bilaterally, which verified the correctness and feasibility of the theoretical analysis.For the characteristics of PWM rectifiers, which are easy for digital realization, the hardware and software of the three phase voltage source rectifier were studied and designed. DSP TMS320F2812 was used as the controller. The main circuit, control circuit, driver and protection circuit of the rectifier were deeply analyzed, including their principles and design methods. Relevant components were selected and their working principles were introduced. Hardware circuits were designed in PROTEL. In CCS integrated environment, Software was designed and debugged. Experimental platform of control system based on DSP was built up and relevant experiments were carried out, experimental results verified the feasibility of the control algorithm further.