M R Sindhu

Photovoltaic based adaptive shunt hybrid filter for power quality enhancement

Power electronic controller based power system equipment are widely used in industrial, commercial and residential sectors. These controllers help in energy saving, but they introduce different power quality issues such as harmonic distortions in current and voltage, voltage sag/swell etc. These power quality issues cause malfunctioning of associated circuits. This paper presents an adaptive shunt hybrid filter where voltage support for DC link capacitor is provided by solar photovoltaic source which improves the power quality by eliminating current harmonics, and improving the power factor. With the help of suitable control algorithm, the filter achieves capability of real power pumping to the grid in addition to harmonic and reactive compensation. The simulation results are carried out with three phase non-linear loads under balanced and/or unbalanced source/load conditions. The results obtained are satisfactory which depicts the effectiveness of the control algorithm and improvement in the power quality with Solar Photo Voltaic integration.

Dynamic Harmonic and Reactive Power Compensation with an Adaptive Shunt Active Filter for Variable Speed Induction Motor Drive

Variable speed drives are mostly preferred in industries, while considering energy saving, smooth control, flexible operation and fast response. On the other hand, this equipment generates dynamic harmonic distortions in source currents and draws variable reactive power demand depending on variation in load condition. These distortions propagate throughout the system and affect all the loads connected to the point of common coupling. Hence a dynamic harmonic and reactive compensator is necessary to enhance power quality to meet current and voltage distortion limits at point of common coupling as per IEEE standard. The most common choice for adjustable speed drives in industries is three phase voltage source inverter based induction motor drives which uses PWM technique for voltage, frequency and current control. This paper presents harmonic analysis of an induction motor drive in an industrial plant and development of adaptive dynamic harmonic and reactive compensator to improve power quality. A digital controller which is programmed with adaptive Artificial Neural Network (ANN) based control algorithm is used for controlling shunt active filter. The simulation and experimental results show that the adaptive shunt active filter provides effective harmonic and reactive compensation in the system under steady state and dynamic load conditions.