A Separate Frequency Tuning Active Filter for Harmonic Resonance Suppression in Radial Distribution Power Systems

• Main Authors: Jian Cheng Li, 李健成
• Other Authors: S. Y. Tseng
• Format: Others
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/92514703949760974775

碩士 === 長庚大學 === 電機工程學研究所 === 97 === Recently, severe voltage distortion resulting from harmonic resonances between power factor correction capacitors and system inductors has been a critical issue in distributed power system. Conventional active filters operating as similar conductance for all harmonic frequencies cannot effectively resolve this problem due to the so-called “whack-a-mole” phenomenon. Therefore, voltage distortion may still be significant and even become worse along the feeder. This thesis presents a discrete frequency tuning active filter to suppress the harmonic resonance in the radial distributed power system. The active filter is installed at the end of the line to operate as variable conductance for each harmonic frequency according to corresponding harmonic voltage distortion. Based on this algorithm, the individual conductance command is autonomously and separately adjusted to damper harmonic resonances in response to variation of both nonlinear loading and resonant capacitors. The peak and rms current of the proposed active filter will be significantly reduced compared with conventional approaches. Therefore, harmonic voltage distortion can be maintained below an allowable level throughout the feeder with low kVA capacity of the active filter. Design considerations of the active filter and a ten-bus radial line are evaluated to verify the theoretical analysis, and a prototype circuit in the laboratory is also designed and implemented to validate the effectiveness of the proposed method.