Least Mean Squares and Recursive Least Squares Algorithms for Total Harmonic Distortion Reduction Using Shunt Active Power Filter Control

Abstract

This paper deals with the use of least mean squares (LMS, NLMS) and recursive least squares (RLS) algorithms for total harmonic distortion (THD) reduction using shunt active power filter (SAPF) control. The article presents a pilot study necessary for the construction of our own controlled adaptive modular inverter. The objective of the study is to find an optimal algorithm for the implementation. The introduction contains a survey of the literature and summarizes contemporary methods. According to this research, only adaptive filtration fulfills our requirements (adaptability, real-time processing, etc.). The primary benefit of the paper is the study of the efficiency of two basic approaches to adaptation ((N)LMS and RLS) in the application area of SAPF control. The study examines the impact of parameter settings (filter length, convergence constant, forgetting factor) on THD, signal-to-noise ratio (SNR), root mean square error (RMSE), percentage root mean square difference (PRD), speed, and stability. The experiments are realized with real current and voltage recordings (consumer electronics such as PC source without power factor correction (PFC), HI-FI amplifier, etc.), which contain fast dynamic transient phenomena. The realized model takes into account a delay caused by digital signal processing (DSP) (the implementation of algorithms on field programmable gate array (FPGA), approximately 1–5 μs) and a delay caused by the reaction time of the proper inverter (approximately 100 μs). The pilot study clearly showed that the RLS algorithm is the most suitable for the implementation of an adaptive modular inverter because it achieved the best results for all analyzed parameters.

Digital Circuit for Seamless Resampling ADC Output Streams

“…Linear interpolators wait for the subsequent sample of the input stream x(n + 1) to compute the value of any sample at a time instant in the midst. Specifically, they compute it by adding to x(n) a term equal to t times the time derivative, which is estimated as first forward difference [32,33].…”

Integration of CFA 2 FB control scheme with modified shunt active line conditioner ( MSALC ) connected distribution system for mitigation of harmonics

“…The filter main operation is the regulation of voltage and the control of power factor. Further, some of the merits are 25 : reduction of harmonics and three-phase neutral return current, improvement of power factor, impact minimization upon the distribution system, voltage regulation and eliminate risk of resonance. [30][31][32][33][34]…”

Design of a Measuring System for Electricity Quality Monitoring within the SMART Street Lighting Test Polygon: Pilot Study on Adaptive Current Control Strategy for Three-Phase Shunt Active Power Filters

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