Sliding Mode and Terminal Sliding Mode Control of Cascaded Doubly Fed Induction Generator

Classical structure of Doubly Fed Induction Generators (DFIGs) is not completely adapted in high-speed regions due to their brushes and slip rings. So in the Cascaded DFIGs (CDFIGs), the rotor windings of a given DFIG are supplied by another wound rotor induction machine leading to a complete brushless structure. This paper presents and compares Sliding Mode Control (SMC) and Terminal Sliding Mode Control (TSMC) methods to control the output voltage of CDFIG. The SMC and TSMC methods are identified as strong controllers with large stability and robustness margins. In this paper, the SMC and TSMC methods are evaluated and compared to the conventional Voltage Oriented Control (VOC) in terms of output voltage change, prime over speed’s variation, and nonlinear load. Simulation and experimental results using a TMS320F28335 based prototype system show that the SMC and TSMC techniques are more robust against parameter variations and uncertainties, and TSMC offers improved dynamic response.