Optimization of Distributed Generation System

The proportional-integral (PI) and neuro controllers of a voltage source cascaded converter with two additional loops for smooth change of islanding and resynchronization operation in a distributed-generation (DG) system is presented in this paper. The first loop is the frequency control loop which is enfolded on the real power set point of the cascaded controller of the voltage source converter to reduce the frequency variation during the change from the grid mode to standalone mode. The second loop is the resynchronization loop which minimizes the phase shift of the AC voltage of the DG unit with the utility grid AC voltage during islanding operation leading to successful grid reconnection event. When the DG unit is connected to grid, produce harmonics problem which can be controlled using PID and neuro controller. THD level for both controller are compared. The comparisons result proves that THD level for neuro controller is smaller than PID controller which is simulated using MATLAB software.
KEY WORDS: Distributed generation (DG), gridsideconverter, pro-portional-integral (PI)