Voltage control of a squirrel-cage self-excited induction generator using Youla-parameterization-based control

Abstract

This paper addresses the regulation of the DC-bus voltage in a small wind energy conversion system intended to supply remote households or operate as a backup power source. The system employs a squirrel-cage self-excited induction generator connected to a DC load through a power electronic interface. To accurately represent the generator behavior under self-excitation conditions, an experimental magnetization curve is developed and incorporated into the system model. A current regulator based on the Youla parameterization approach is designed to control the direct and quadrature current components within a vector-control framework. The proposed control strategy aims to ensure stable DC-bus voltage regulation while improving current quality. Simulation studies carried out in MATLAB/Simulink demonstrate the effectiveness of the proposed model and control strategy. In closed-loop operation, the proposed controller accurately tracks reference values and effectively reduces current harmonic distortion. Compared with conventional proportional–integral (PI)- and RST-based Voltage-Oriented Control schemes, the proposed Youla-based controller achieves improved dynamic performance by achieving the lowest current THD 1.03% under speed variations, outperforming the PI controller (THD = 1.10%) and the RST controller (THD = 2.23%). These results confirm the suitability of the proposed approach for autonomous wind energy systems operating in isolated environments.