等效无限长有源电力滤波器在环形配电网中的应用

Study on Applications of Infinite Active Power Filters in Closed-loop Distribution Power Systems

随着高科技园区等用户对供电可靠性要求的提高,环形配电网成为一种发展趋势。与射线型配电网相似,由功率因数校正电容和系统自身电感导致的谐波谐振现象,使得环形配电网中的谐波污染问题成为人们关注的焦点之一。该文针对环形配电网中谐波谐振现象,基于将环形配电网等效为射线型配电网的基本思想,提出一种在环形配电网中点安装等效无限长有源电力滤波器(infinite active power filter,I-APF)的谐波抑制方案。相比于在环形配电网中点安装阻性有源电力滤波器(resistive active power filter,R-APF)的传统方案,该方案不仅能够获得更好的谐波抑制效果;同时,该方案对于安装位置的改变、电容的改变和非线性负载的改变,均具有更好的适应性和谐波抑制效果。仿真分析和实验结果均验证了该方案的正确性和有效性。

With the increasing demand for electric-power reliability in high-tech parks or in metropolitan areas, the closed-loop distribution power system has become a trend. The harmonic resonance caused by capacitors for power factor correction and system inductors may lead to significant voltage distortion along the feeder. This paper proposes an infinite active power filter（I-APF） to damp out the harmonic resonance. The I-APF is installed at the middle point of the closed-loop distribution feeder, which is equivalent to a radial feeder. Compared with the traditional resistive active power filter（R-APF）, the proposed strategy has better capability of harmonic damping, especially in response to variation of non-linear loads or resonant capacitors. The proposed strategy can also accomplish harmonic suppression effectively, even if the installation location of I-APF deviates from the middle point. Both simulation and experiment results have been provided to validate the proposed strategy.