Wind energy conversion system using perturb & observe-based maximum power point approach interfaced with T-type three-level inverter connected to grid
S Pranupa, A. T. Sriram, S. Nagaraja Rao
Abstract
Abstract In this paper, the performance of a permanent magnet synchronous generator (PMSG)-based wind energy conversion system (WECS) supplied to an uncontrolled rectifier-fed boost converter (BC) interfaced with a three-phase T-type three-level inverter (TLI) has been analysed. The proposed WECS involves three converters, namely an uncontrolled rectifier that is used for conversion from AC to DC; a BC supplied by a PMSG-fed rectifier used to enhance the voltage gain; and a grid-connected three-phase T-type TLI is proposed to eliminate power-quality issues with synchronization of grid voltage and current. The main goal of this research is to model and control the grid-connected T-type TLI using a d–q synchronous frame for wind energy for regulating the DC-link voltage and transferring the generated wind power from the BC to the grid. Furthermore, the perturb & observe (P&O)-based maximum power point (MPP) approach is recommended to keep track of the MPP for a BC that is supplied from a PMSG-based WECS under constant and variable wind speeds. The proposed PMSG-based WECS interfaced with grid-connected T-type TLI using d–q control has been computationally modelled, simulated and validated with constant and variable speeds using MATLAB® and Simulink®. It is confirmed that the P&O-based MPP approach ensures maximum power for varying wind speeds, and the total harmonic distortion of the T-type TLI grid current value is 3.18%, which is within IEEE-519 limits. Furthermore, with grid synchronization, the power factor of the T-type TLI is maintained at unity to avoid power-quality issues.