%0 Journal Article %T Survey on Microgrid: Power Quality Improvement Techniques %A Chitra Natesan %A Senthil Kumar Ajithan %A Priyadharshini Palani %A Prabaakaran Kandhasamy %J ISRN Renewable Energy %D 2014 %R 10.1155/2014/342019 %X Microgrid became one of the key spot in research on distributed energy systems. Since the definition of the microgrid is paradigm of the first time, investigation in this area is growing continuously and there are numerous research projects in this moment all over the world. The increased infiltration of nonlinear loads and power electronic interfaced distribution generation system creates power quality issues in the distributed power system. In this paper, a comprehensive survey on microgrid to improve the power quality parameters is taken as the main objective. Furthermore, the detailed investigations are explored in this paper for the enhancement of power quality issues with the help of an optimization technique, filters, controllers, FACTS devices, compensators, and battery storage. 1. Introduction Microgrid [1] may be defined as an agglomeration of distributed generation (DG) units usually linked through power electronic based devices (voltage source inverter) to the utility grid. DG units can be built with nonconventional energy sources such as fuel cells, wind turbines, hydroelectric power, and solar energy. Microgrid can function either tied to the grid or isolated from the grid. The impact of power quality hitches is concerning while linking microgrid to the main grid and it could become a foremost area to investigate. If unbalance in voltage is alarming, the solid state circuit breaker (CB), connected between the microgrid and utility grid, will open to isolate the microgrid. When voltage unbalance is not so intense, CB remains closed, resulting in sustained unbalance voltage at the point of common coupling (PCC). Generally power quality problems are not new in power system, but rectification methodology has increased in recent years. Maintaining a near sinusoidal power distribution bus voltage at rated magnitude and frequency is referred to as electric power quality. In addition, the energy supplied to a customer must be interrupted from the reliability perception. Voltage unbalance, harmonic content, increased reactive power demand, and frequency deviation are the foremost power quality hitches which affect the utility grid. Generally, current harmonic and voltage-frequency imbalance increase losses in AC power lines. A synchronous reference frame based current control loop and conventional PI regulator are used for voltage-frequency regulation [2, 3]. Voltage unbalance has been mitigated by indirect current control technique in [4]. DGs are capable of offering high flexibility to robustness along with versatile control of active and %U http://www.hindawi.com/journals/isrn.renewable.energy/2014/342019/