The propagation of nonlinear loads and distributed power generation systems can cause power quality problems such as harmonic distortion, system imbalance, and resonance problems. Shunt active power filters are used to eliminate these power quality problems. A recently proposed control scheme for a shunt active power filter utilized a time-domain transformation to extract positive and negative sequence components of the system voltages and currents. These components are used in a modified version of instantaneous reactive power theory to calculate the reference currents for a three-phase inverter. Changes in the system operating conditions can cause the system frequency to vary, which can impact the performance of the time-domain transformation. Proposed in this paper is a frequency adaptive control scheme to compensate for frequency variations. Several simulation and experimental tests have been performed to validate the operation of the proposed frequency adaptive control scheme.

中文翻译：

---

三相并联有源电力滤波器频率自适应控制方案

非线性负载和分布式发电系统的传播会引起谐波失真、系统不平衡和谐振问题等电能质量问题。并联有源电力滤波器用于消除这些电能质量问题。最近提出的并联有源电力滤波器的控制方案利用时域变换来提取系统电压和电流的正序和负序分量。这些组件用于瞬时无功功率理论的修改版本，以计算三相逆变器的参考电流。系统操作条件的变化会导致系统频率发生变化，这会影响时域转换的性能。本文提出了一种频率自适应控制方案来补偿频率变化。