Adaptive active filter for interfacing wind-power DGs to distribution systems

Wind-power distributed generation (DG) converters may inject considerable amount of harmonics into their connected distribution systems that could exceed its connected utility tolerance or IEEE 1547 Std. limits. This paper presents a new adaptive harmonics detection active (AHDA) filter that is designed to suppress harmonics produced by wind DG converters. The AHDA filter consists of an inverter of industrial-proven configurations, controlled using a new adaptive noise cancellation (ANC) algorithm and implemented with state-of-the-art digital signal processing technology. The ANC algorithm is based on a novel noise cancellation theory that was originally created for image signal processing but not for power engineering. This paper presents a practical formulation of the ANC algorithm for harmonics elimination at utility-DG interfaces, with significant simplification of the original complex formulation for noise cancellations. Hardware and software implementations of the AHDA filter are detailed. Simulation and experimental results are provided to demonstrate the effectiveness of the AHDA filter.