Dynamic Startup Characteristics Analysis of Single-winding Pole Changing Line-start Canned Solid-Rotor Induction Motor with Squirrel-cage

The canned induction motors are widely used in nuclear equipment due to its high reliability and good mechanical properties. However, the complex distribution of electromagnetic field in the rotor makes it difficult to analytical calculate its performance. This paper presents a method for calculating and analyzing the dynamic startup characteristics of a single-winding pole changing canned solid-rotor induction motor with squired-cage (CSRIMSC). Using the 2D-multilayer electro-magnetic theory, the equivalent circuit of the CSRIMSC is determined while considering the magnetic saturation and skin effect. Then, the branch analysis and multi-loop model combined with the state-space method is used to analyze the dynamic characteristics of the whole startup and pole changing process, in which the pole switching process is the most important part. The mutual leakage inductances of each branch of rotor side and the current and flux variation of parallel branches in stator side will be taken into consideration.