Modular Design and Realization of a Dynamic Voltage Restorer

• Main Authors: Hong-chieh Chang, 張弘杰
• Other Authors: F. S. Pai
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/91813297925433360396

碩士 === 國立臺南大學 === 電機工程研究所 === 98 === The Dynamic Voltage Restorer (DVR) is an inverter that injects a set of ac output voltages in series with the incoming distribution supply voltage such that the voltage sag problem can be effectively solved. It is based on the field experience reported in the survey that the utilization of DVR did alleviate the voltage-sag problems, which has attracted considerable interests over the past few years. In this thesis based on the paradigm of the cascade inverter technique, a new approach to control the dynamic voltage restorer will be proposed. In the method, the required series voltage for the sag correction is first decoupled by the vertical and horizontal component referred to the phase of load current. The vertical and horizontal voltage component is then generated and compensated via the different reactive and active power module. In this case, as the super capacitor-aided reactive power module can output a large amount of the compensation power, the proposed system will take full advantages of less real power injection during the DVR operation, mitigating a severe and long duration voltage sag with a significantly smaller energy demand from the cascaded inverter. The method proposed in this thesis will be examined under various scenarios. The results help consolidate the feasibility and practicability of the approach for the applications considered.