The equivalent circuit parameters calculation of induction motors with ring windings

Induction motors with ring windings (IMRW) are designed for the processing of nuclear waste. The stator winding coils are covered with ceramic insulation to allow for long-term operation in conditions of increased radiation. The stator coils are ring shaped, in order to reduce the bend angle. The stator has a specific design consisting of tooth tips located around the axis of rotation and tooth cores placed over the tooth tips in a spiral. The first IMRW prototype was manufactured by UrFU together with “Uralelectromash”. It was designed to the same diameters as an induction motor of a classical design with a power P = 2.2 kW, with a synchronous rotation speed n = 1000 rpm. The fundamentally new armature design involves the search for new solutions for determining machine parameters, such as inductances, electromagnetic torques. The article discusses a method of equivalent circuit parameter calculation for IMRW using the “ANSYS Maxwell” in 3D mode. In order to determine stator winding leakage inductances, a static analysis of the model with the rotor removed was used. Mutual inductance is defined as the difference between stator winding phase impedance and leakage inductance. The active resistance of the magnetizing circuit and the impedance of the motor can be determined using the IMRW no-load and short-circuit characteristics obtained in ANSYS Maxwell. The paper also provides an example of calculating the mechanical characteristics of a motor using the analytical method (AM).This involves the use of equivalent circuit parameters, and the finite element method (FEM). The use of FEM for calculating the mechanical characteristics implies the analysis of IMRW in a dynamic mode. This allows the electromagnetic torque to be determined at a user-specified rotor speed. In conclusion, a comparative analysis of the parameters of a classic engine and IMRW engine, of the same size, is given. Recommendations are given for further improvement of the design of IMRW engines.