High order sliding mode control of permanent magnet synchronous generator-based wind energy conversion systems

As renewable energy resources such as wind become more prolific, the challenges in utilizing these resources to their full efficiency come to the forefront of power system engineers. Although the sustainability of such alternative energy resources is attractive, the ability to obtain satisfactory efficiency has been difficult until recent advances in nonlinear control technologies. The subject of this paper pertains to sliding mode control and its application in nonlinear electrical power systems as seen in wind energy conversion systems. Due to the robustness in dealing with unmodeled system dynamics, sliding mode control has been widely used in electrical power system applications. This paper presents first and high order sliding mode control schemes for permanent magnet synchronous generator-based wind energy conversion systems. Application of these methods for control using dynamic models of the d-axis and q-axis currents, as well as those of the high speed shaft rotational speed show a high level of efficiency in power extraction from a varying wind resource. Computer simulation results have shown the efficacy of the proposed sliding mode control approaches.