**2. Configuration of DPGS and its control**

The configuration of Distributed Power Generation System depends on input power sources (wind, solar etc) and different hardware configurations are possible. The basic structure of DPGS is shown in fig.1. The system consists of renewable energy sources, two back-to-back converters with conventional pulse width modulation techniques, grid filter, transformer and utility grid [1].

The input-side converter, controlled by an input side controller, normally ensures that the maximum power is extracted from the input power source and transmits the information about available power to the grid-side controller.

The main objective of the grid-side controller is to interact with the utility grid. The gridside controller controls active power sent to the grid, control of reactive power transferred between the DPGS and the grid, control of the DC-link voltage, control of power quality and grid synchronization. Gird filter and transformer eliminates harmonics is inverter output voltage and ensures proper synchronization of inverter with grid.

Fig. 1. General structure of distributed power generating system
