Real-Time Particle Swarm Optimization based Parallel Hybrid Active Power Filter under Variable Load Conditions

In electrical distribution system, nonlinear loads draw reactive power and / or undesired harmonic currents from ac source along with the fundamental current. Various power quality compensators are being considered as potential candidate for solving such power quality problems not only in ideal supply but also in distorted supply conditions. This paper presents a new method for harmonic and reactive power compensation using a Particle Swarm Optimization (PSO) algorithm for Parallel Hybrid Active Power Filter (HAPF) for power quality improvement under dynamic loading and non-ideal mains conditions. The PSO comprises two similar swarm group (swarm size-25), and it has been designed to extract fundamental frequency components from non-sinusoidal and unbalanced currents instead of conventional low pass filter. The reactive power compensation is done without sensing load currents, which gives simplicity in control with less number of current sensors. The performance of the parallel HAPF with the proposed particle swarm optimization compensation algorithm is found to be considerably effective and adequate to compensate harmonics and reactive power. The experimental results show excellent behavior of PSO based controller and performances of parallel HAPF under various load conditions.