Control laws for sliding mode speed control of variable speed drives

This paper presents an investigation of various control laws to study the characteristics of sliding mode speed control (SLMSC), and to overcome some disadvantages of SLMSC such as steady state speed chattering and error. It is demonstrated that, by the appropriate choice of a suitable control law, a robust, fast and accurate SLMSC performance, with reduced steady state chattering and error, can be achieved in a practical variable speed drive system. Digital simulation and experimental results based on a self-controlled synchronous motor (SCSM) are presented to substantiate the analysis.