Performance assessment of two active power filter control strategies in the presence of non-stationary currents

TL;DR

This paper evaluates two active power filter control strategies for mitigating harmonics and reactive power in non-stationary, unbalanced loads using a hybrid EMD and p-q theory approach, validated through experimental comparison.

Contribution

It introduces a novel hybrid control strategy combining EMD with modified p-q theory for improved harmonic and disturbance separation in APF systems.

Findings

The hybrid EMD and p-q control outperforms conventional methods in harmonic mitigation.

The proposed approach effectively isolates non-stationary disturbances.

Experimental results confirm enhanced power quality with the new control strategy.

Abstract

This paper describes an active power filter (APF) control strategy, which eliminates harmonics and compensates reactive power in a three-phase four-wire power system supplying non-linear unbalanced loads in the presence of non-linear non-stationary currents. Empirical Mode Decomposition (EMD) technique developed as part of the Hilbert-Huang Transform (HHT) is used to singulate the harmonics and non-linear non stationary disturbances from the load currents. The control strategy for the APF is formulated by hybridizing the so called modified p-q theory with the EMD algorithm. A four-leg split-capacitor converter controlled by hysteresis band current controller is used as an APF. The results obtained are compared with those obtained with the conventional modified p-q theory, which does not possess current harmonics or distortions separation strategy, to validate its performance.