Coordinated Predictive Control of a Wind/Battery Microgrid System

This paper presents the operation and controller design of a microgrid consisting of a direct drive wind generator and a battery storage system. A model predictive control strategy for the ac-dc-ac converter of wind system is derived and implemented to capture the maximum wind energy as well as provide desired reactive power. A novel supervisory controller is presented and employed to coordinate the operation of wind farm and battery system in the microgrid for grid-connected and islanded operations. The proposed coordinated controller can mitigate both active and reactive power disturbances that are caused by the intermittency of wind speed and load change. Moreover, the control strategy ensures the maximum power extraction capability of wind turbine while regulating the point of common coupling bus voltage within acceptable range in both grid-connected and islanded operations. The designed concept is verified through various simulation studies in EMTDC/PSCAD, and the results are presented and discussed.