Integration of DC power source in micro-grid using VSI with PLL technique

The looming energy crisis is becoming the greatest challenge to the world today. As a consequence of this there is an increasing attention for alternative renewable energy resources. In future, renewable energy sources will be integrated with energy storage and it will require a proper converter for integrating with the grid. In order to achieve this, various power electronics topologies have to be incorporated between the grid and the renewable source(s). This paper presents the simulation and experimental implementation of DC power source integration in micro-grid using single phase `Voltage Source Inverter' (VSI) with `Phase Locked Loop' (PLL) topology. Firstly the appropriateness of the PLL technique for the micro-grid synchronization is analyzed under the normal condition, harmonic condition and the non-harmonic (e.g. impulse) condition of a power system using Matlab Simulink®. Then the design and experimental implementation steps of the grid-tied VSI are discussed in details. In this work, a VSI with PLL technique is presented with simulation and experimental results for integrating with 230V/50Hz low voltage grid.