Calculation and compensation of PCC voltage variation using a grid connected inverter of a wind turbine in a weak grid

In a hybrid power system where wind power generators are installed in a weak grid, the prediction, investigation and compensation study about the power quality is necessary. Especially, the voltage variation is one of the most important issues for the application of high penetration of wind farm in a week grid. As part of an experimental program to evaluate wind turbine generator performance on the isolated diesel power system, a simplified model for voltage deviation calculation is developed and tested according to the installation capacity of wind power. A method of voltage compensation is proposed using the reactive power output which can be calculated analytically. Results of calculation and compensation algorithm are compared to mitigate the voltage variation problem. As a result the prediction error of the voltage variation at PCC (Point of Common Coupling) was tower than 10% of the actual value. The voltage variation is effectively compensated using the proposed method and the required increase of the inverter capacity for the compensation is calculated.