| Summary: | 碩士 === 國立東華大學 === 電機工程學系 === 105 === This thesis presents a comparative study on applying two control methods, named as hysteresis-band control and vector control, to a three-phase pulse-width modulation (PWM) rectifier to achieve DC voltage regulation, unity power factor, and AC current harmonic reduction. Besides, in hysteresis-band control, there are software and hardware implementations discussed.
The three-phase PWM rectifier is set up by a full-wave, six power-switch modules, and three boost inductors in the AC line. An inner-loop current controller with power factor correction and an outer-loop voltage controller are performed in the two control methods. The hysteresis-band control method is based on the outer-loop PI voltage controller and the hysteretic current-switching controller to let the amplitude and phase of the AC line current be completely controlled. The vector control is based on a synchronously rotating d-q coordinate frame that the three-phase voltages and currents can be represented by two state variables in the d-q coordinate frame. Then, from the state variables in the d-q frame, the vector control with PI voltage and current controllers are developed.
To demonstrate the performance of the three-phase PWM rectifier with the two control methods, a laboratory prototype of DSP controller-based 800W three-phase rectifier was carried out. Experimental results from the laboratory rectifier are illustrated for comparative analysis on the power factor correction, conversion efficiency, and total harmonic distortion.
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