Implementation of proportional-resonant controller in an autonomous distributed generation unit

The control of interfacing inverter in a renewable energy generation is critical for an autonomous generation unit as the voltage stability in such a system is solely determined by the interfacing inverter. Traditional voltage controlled inverters implement PI controllers to track the reference voltage. However, the PI controllers require dc quantities to provide zero steady state error. Moreover, the performance of a single PI controller may be inadequate for a system with nonlinear loads. This paper presents the implementation of Proportional Resonant controller which provides zero steady state error with sinusoidal reference signal. Also, PR controllers may offer better performance and less computational complexity for system with nonlinear loads. The proposed PR implementation has been tested using MATLAB/SIMULINK based simulation studies.