Effective supervisory controllers designed for optimal energy management in permanent magnet synchronous generator wind turbine with battery storage

Abstract

Optimal control of large-scale wind turbine has become a critical issue for the development of renewable energy systems and their integration into the power grid to provide reliable, secure, and efficient electricity. In this article, a new supervisory control system for the optimal management and robust operation of a wind turbine generator and a battery energy storage system is presented. The proposed coordinated controller can mitigate both active and reactive power disturbances due to the intermittency of wind speed and load change. Moreover, the control strategy ensures the maximum power extraction capability of direct-drive wind turbine. This supervisory controller is made up of three subsystems. The first one is used to track the maximum power point for variable wind speeds; the control algorithm employs a fuzzy logic controller and a second-order sliding mode controller to effectively meet this target. The task of the second one is to maintain the required DC-link voltage level. This is achieved by controlling the bidirectional power flow in the storage batteries using DC–DC converter. Whereas in the last, a second-order sliding mode controller is investigated to achieve smooth regulation of grid active and reactive power quantities, which provides better results in terms of attenuation of the harmonics present in the grid courant compared with the conventional first-order sliding mode controller. Extensive simulation studies under different conditions of wind speed are carried out in MATLAB/Simulink, and the results confirm the effectiveness of the new supervisory control system.