A Reduced-Part Soft-Switching Three-Phase AC Voltage Regulator

• Main Authors: Min-Lun Tsai, 蔡旻倫
• Other Authors: Maoh-Chin Jiang
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/3yfybp

碩士 === 國立宜蘭大學 === 電機工程學系碩士班 === 101 === This thesis presents a reduced-part soft-switching three-phase ac voltage regulator. This study includes a soft-switching three-phase five-arm ac voltage regulator, a three-phase five-arm series compensation voltage regulator and a soft-switching three-phase four-arm ac voltage regulator. The proposed ac voltage regulators can solve the unusual voltage situations such as under-voltage, over-voltage, voltage sag, voltage swell and three-phase unbalanced source and load. The proposed voltage regulators can maintain a stable output voltage and the input current can achieve unity power factor. The proposed voltage regulator combines a three-phase rectifier with a three-phase inverter in a common dc-link. Besides using simple resonant units, all main switches are operated at zero-voltage-switching (ZVS) turn-on. Also, all auxiliary switches are operated at zero-current-switching (ZCS) turn-off. Rather than the conventional three-phase six-arm ac voltage regulator, the proposed five-arm and four-arm ac voltage regulator can reduce the number of main switches. Moreover, the reduction in the number of main switches not only can simplify the control circuit but also can increase the system reliability. In addition, a simple feed forward controller, based on the energy balance concept, is proposed to control the voltage of energy-storage capacitors. Since the energy change in the energy-storage capacitors can be fast compensated, the transient performance of the proposed voltage regulator can be improved. After all, some simulation and experimental results are presented to verify the feasibility of the proposed reduced-part soft-switching three-phase ac voltage regulator.