Ontario in 21st century is progressing rapidly to source a bulk of its energy supply from green and renewable energy sources, including wind energy. However there are technical challenges. A significant limiting factor in the large-scale integration of wind energy is the inherent intermittent nature of wind supply. The purpose of the research project is to develop appropriate control systems to integrate energy storage into the Ontario electricity grid given that energy storage constitutes a fundamental component of a modernized electricity grid. The challenges are multiple. Given that wind generators driven by wind have an output that is intermittent and highly variable, as a result the power supply voltages on distribution lines change at a rapid rate. This research develops a control strategy for the flywheel system to inject or draw real power to or from the connected line on a voltage command, thereby mitigating voltage swings created by variable and intermittent power supply from wind generators.