Analysis of PI and PR controllers for distributed power generation system under unbalanced grid faults

Abstract

It is the general trend to increase the electricity production using distributed power system (DPGS), which is based on renewable energy sources such as wind, solar, fuel cell etc. These systems are to be properly controlled in order to provide reliable power to the utility network. For that power electronics converters are used as an interfacing device between DPGS and utility network. In case of unbalanced fault, the major problem in distributed power generation system is the phase unbalance which causes the power quality problem along with grid instability. This paper discuses the implementation of two different controllers namely Proportional — integral (PI) and proportional resonant (PR) controllers in order to obtain the control of grid side converter during single phase to ground fault. The analysis includes the grid current harmonic distortion along with the variation of active and reactive power during the fault condition. The system is simulated using MATLAB software and simulation results demonstrate the effectiveness of both the controller.