A Filter-Less Time-Domain Method for Reference Signal Extraction in Shunt Active Power Filters

Current distortion degrades power quality and affects system performance, especially for sensitive loads that require pure sinusoidal waves. Owing to its excellent dynamic response, a well-designed active filter (APF) can achieve total harmonic (THD) within the acceptable limits defined by IEEE 3002 standards through compensating distortions. The APF consists of two main modules: reference signal extraction module modulation module. This paper adapts matrix pencil method, well-known model-based parameter estimation technique, problem extraction. Contrary conventional time-domain methods such as synchronous frame (SRF) reactive theory (PQ theory) rely on low-pass filters in their implementations, proposed method does not use filter. However, it extracts first decomposing load current into constituent frequency components, then subtracting sine wave synthesized from obtained fundamental component current. Results simulated data MATLAB/Simulink confirm higher accuracy fast response time extracting signal.