An Integrated System of Wound Rotor Induction Motor Soft Starting and Doubly-fed Speed Adjusting

An integrated system of wound rotor induction motor soft starting and doubly-fed speed adjusting was proposed. It consists of variable reactance converter, electronic power inverter, controller and wound rotor induction motor. The hardware design of the integrated system was illustrated in detail. When soft starting, variable reactor technique was adopted. While doubly-fed speed adjusting, double closed-loop controlling was applied to the system. Also the software programming flowchart was proposed. The principle of vector control was used in soft design. In addition, the simulation of the system was made using Matlab/Simulink, including the simulation of soft starting and speed adjusting. Finally, the experiment of soft starting and speed adjusting was done. The results proved that the integrated system can realize both soft starting and speed adjusting and its performance price ratio is better than frequency converter.