Finite element analysis of transient electromagnetic‐thermal phenomena in a squirrel cage motor

Abstract

Purpose -The purpose of this paper is to elaborate the method and algorithm for the analysis of electromagnetic and thermal transients in a squirrel cage induction motor. Design/methodology/approach -The paper presents the special software for transient finite element (FE) analysis of coupled electromagnetic-thermal problems in a squirrel cage induction motor. The software has been prepared and is successfully applied in the design of special squirrel cage motors, e.g. the motors working in cryogenic conditions. A time-stepping FE method and transients analysis of an induction motor has been applied. The nonlinearity of the magnetic circuit, the movement of the rotor and the skewed slots have been taken into account. The results of computations have been compared with measurements. Findings -The method presented and the elaborated specialised software for FE analysis of electromagnetic and thermal transients are used to determine the dynamic performance of the squirrel-cage induction motor. The results of simulations compared with measurements confirm the adequacy of this approach to the analysis of coupled electromagnetic-thermal problems.Research limitations/implications -3D effects have only been taken into account by quasi-3D techniques (e.g. the multi-slice for the skewed rotor slots). Practical implications -The software developed can be useful in the analysis and design of squirrel cage motor, especially motors working in cryogenic conditions. Originality/value -The paper offers appropriate software for transient analysis of coupled electromagnetic and thermal problems in squirrel cage motors with skewed slots.

An Enhanced Dynamic Simulation Model of a Hybrid Magnetic Bearing Taking Account of the Sensor Noise

“…Additionally, the circuit equations can assimilate an inverter supply system [3], the distorted voltage-excited sources [8], as well as those from capacitors [9]. Moreover, this type of model facilitates coupling between the electromagnetic and thermal fields [10]. Contemporary software dedicated to the calculation of magnetic field distributions (e.g., Ansys Maxwell 3D, Comsol) allows performing the simulations of transients based on the field-circuit directly coupled FEM [4]; it is even possible to incorporate (into the simulation model) the required control loops essential to achieve magnetic levitation [7].…”

FE analysis of current displacement phenomena in a squirrel cage motor working at cryogenic temperature

“…Each section concerns a different position of the rotor with respect to the stator [1][2][3][4][5][6]. In presented model the windings segmented into elementary conductors associated with disks [4,6].…”

“…The time discretization leads to the following system of non-linear algebraic matrix equations [1,2] ( ) ( ) (9) where n denotes the number of time-steps, ∆t is the time-step length.…”

“…Reliability design calculations strongly depends on the accuracy with which the applied mathematical model representation the phenomena in a considered machine. Thus, in a consideration is necessary to take a full account of the movement of the rotor, nonlinear properties of magnetic materials, influence of temperature on electric, magnetic and thermal properties of the materials, eddy-current distribution in the rotor bars and skewed slots [1][2][3]. This problem is especially important during the analysis and design of a special squirrel cage motor, e.g.…”

Design and Damping Analysis of a New Eddy Current Damper for Aerospace Applications

“…The computation procedure is applied to an eddy current braking system of a high velocity train and the resulting braking forces are compared to measurements. Baranski et al (2011) perform the transient electromagnetic finite element analysis of the eddy current damper for a last stage steam turbine blading and carry out parameter studies to calculate its equivalent damping factors. Laborenz et al (2011) offer special software and elaborate its algorithm for transient finite element (FE) analysis of coupled electromagnetic-thermal problems in a squirrel cage induction motor.…”