Design and control process of SEPIC converter for maximum power extraction in wind energy conversion systems

Operating point of a given wind energy conversion system (WECS) changes due to variations in wind velocity and applied load. As a consequence, mode of operation of the dc-dc converter, which implements maximum power point tracking (MPPT) control algorithm, shuttles between continuous conduction mode (CCM) and discontinuous conduction mode (DCM). Moreover, conventional design process of a converter for CCM operation and control system design principles, which are primarily focused for the regulation of its output voltage, are not applicable for MPPT control implementation. This paper presents the design process of single-ended primary inductor converter (SEPIC) for CCM operation throughout the operating range of a small-scale WECS and discusses the digital redesign process of DSP-based digital control system for effective MPPT control algorithm implementation. TMS320F28335 DSP controller based experimental setup is used for the evaluation of the proposed controller configuration.