Power Quality Improvement of Micro Grid by Using DVR

Power quality is defined as the degree of voltage, current, frequency and waveform of power system under designed specification of the system. While transmitting the power from one end (generation) to another (load) utility has to face some power quality issues such as voltage sag, voltage swell, harmonics, inter-harmonics, voltage imbalance, voltage fluctuation, short duration voltage variation, long duration voltage variation, transient, power frequency variation, waveform distortion etc. These power quality issues directly effect on the efficiency of the power system and performance of the load equipment’s. Problems like voltage sag, voltage swell occurs due to sudden removal of large load from the system, energization of large capacitor bank or system fault like single-line-to-ground fault. These types of problems directly effect on equipment performance and accuracy, especially on sensitive equipment’s as computer, medical instruments, some electronic devices etc. To mitigate voltage sag, voltage swell problem in power system various devices are used such as DVR (dynamic voltage restorer) Key Words: Voltage sag, Voltage swell, Power quality, MATLAB simulation, Single-phase AC system, Single-phase AC load.