Design of dual function solar inverter to mitigate power quality events in weak grids

Power distribution in weak grid areas has a large number of power quality problems which include sag, swell, flicker etc. Each of the power quality issue has negative effect on the life and operation of sensitive loads like television, power drives, displays, lighting loads. This paper presents dual function solar inverter to mitigate power quality events in solar distributed generation system connected with weak grid. The proposed system will not only mitigate power quality problems of the weak grid but will also integrate solar modules with the grid and will thus reduce the effective cost of the grid connected solar systems. Suitable control scheme, detailed operation under voltage sag along with switching pattern is presented. Different voltage sag and swell events have been simulated by the developed MATLAB/SIMULINK model. The results of simulation verify the ability of the proposed system to mitigate voltage sag/swell events. The effect of DC-link capacitor size on the performance of dual function solar inverter is also presented.