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This paper presents a reliable microgrid for residential community with modified control techniques to achieve enhanced operation during grid connected, islanded, and resynchronization mode. The proposed microgrid is a combination of solar photovoltaic, battery storage system and locally distributed generation (DG) systems with residential local loads. A modified power control technique is developed such that local load reactive power demand, harmonic currents, and load unbalance are compensated by respective residential local DG. However, active power demand of all local residential load is shared between the microgrid and respective local DG. This control technique also achieves constant active power loading on the microgrid by supporting additional active power local load demand of respective residential DG. Hence, proposed modified power control technique achieves transient free operation of the microgrid during residential load disturbances. An additional modified control technique is also developed to achieve seamless transition of microgrid between grid-connected mode and islanded mode. The dynamic performance of this microgrid during grid-connected, islanded, and resynchronization mode under linear and nonlinear load variations is verified using real-time simulator. [ABSTRACT FROM AUTHOR]

This paper presents real-time implementation of a grid interfaced distributed generation (DG) system with modified current control loop using three phase amplitude adaptive notch filter (AANF) based synchronization tool. A grid current feedback based modified $dq$-current control technique for interfacing inverter is developed in order to achieve constant loading on the grid, transient-free operation, and power factor improvement close to unity power factor (UPF) of the utility grid during sudden load variations. This technique does not require separate calculation of reference reactive component and harmonics component of currents hence reduces control circuit complexity. In addition, it requires only three voltage and three current sensors. Three phase AANF is developed and is used for online extraction of utility voltage phase angle to generate synchronized reference current signals for interfacing inverter. AANF is used because of its adjustable accuracy and amplitude adaptability even under unbalanced voltage sag and swell, frequency variation, and distorted grid conditions. Fast and accurate behavior of three phase AANF improves the dynamic response of entire DG system control performance for sudden load variations. The dynamic behavior of the proposed grid interfaced DG system is experimentally evaluated in maintaining constant loading on grid, transient-free operation, and power factor improvement close to UPF operation of the utility grid, by compensating total reactive power and harmonic current demanded by variable linear as well as nonlinear load. [ABSTRACT FROM PUBLISHER]