This paper describes different power quality problems in distribution systems and their solutions with power electronics based equipment. A hybrid power filter in combined system of shunt passive and series active power filter has been designed and simulate with Matlab/Simulink. This filter is a three level PWM voltage source inverter and we use a fuzzy logic controller algorithm to control the...

Two energy hybrid filter systems were considered which reduce level of higher mains current harmonics. An advantage of such system is low demanded active filter power because in complements only passive filter operation. The first considered system has inverter switched on in series with shunt passive filter. Through optimization of control parameters it is able to eliminate specific higher mai...

The change in system voltage and frequency with changing load creates problem in power system stability. For the sake of system stability and reliability, the reactive power compensation is essential for flexible AC transmission system (FACTS). The variation of reactive power causes impact on the generating units, lines, circuit breakers, transformers, relays and isolators. However the reactive...

ABSTRACT In this paper, we apply the PQ theory with shunt active power filter in an unbalanced and distorted power system voltage to compensate the perturbations generated by non linear load. The power factor is also improved in the current source. The PLL system is used to extract the fundamental component of the even sequence under conditions mentioned of the power system voltage.

ABSTRACT This paper presents a new algorithm for harmonic estimation in power systems. It utilizes separable least squares (SLS) technique to estimate the magnitude and phase angle of the harmonics by analyzing the waveform. As well as hybrid techniques have been utilized in this paper to estimate harmonics, real coded genetic algorithm (RCGA) and particle swarm optimization (PSO) utilized to e...

The term ‘power quality’ [1-2] refers to the purity of the voltage and current wave-form, and a power quality disturbance is a deviation from the pure sinusoidal form. Harmonics superimposed on the fundamental are one cause of such deviations. Power quality problems [1-2] like voltage harmonics, voltage flickers, voltage sags and voltage swells, current harmonics, current unbalance, reactive cu...

Nowadays with increasing use of numerous nonlinear loads, voltage and current harmonics in power systems are one of the most important problems power engineers encounter. Many of these nonlinear loads, because of their dynamic natures, inject time-varying harmonics into power system. Common techniques applied for harmonics measurement and assessment such as FFT have significant errors in presen...