Finite element analysis of the asynchronous torque in LSPMSM with non-symmetrical squirrel cage winding

Abstract

The paper focuses on the analysis of the asynchronous torque of the line start permanent magnet synchronous motor (LSPMSM) with the asymmetrical squirrel cage winding. In order to calculate the asynchronous torque the parametrical fieldcircuit models of LSPMSM have been elaborated on. Further, the models have been applied to investigate the impact of squirrel cage asymmetry on the asynchronous torque. The evaluated asynchronous torque vs. rotor speed characteristic of proposed motor with asymmetrical cage has been compared with the characteristics of reference asynchronous motor and LSPMSM with symmetrical cage winding. It has been found that deepening of chosen bars of the cage improves the starting properties of the LSPMSM.

Comprehensive Parameters Identification and Dynamic Model Validation of Interior-Mount Line-Start Permanent Magnet Synchronous Motors

“…L can be replaced by L d if the rotor d-axis is aligned with phase-a or replaced by L q if the rotor d-axis is aligned with phase-a. Accordingly, by using the step response plot, the time constant can be measured, which is then used to calculate L d and L q using Equation (16).…”

“…Based on circuit theory, the equivalent circuit of the tested motor during the test is a resistance-inductance circuit, as shown in Figure 12. Therefore, the current in the circuit can be described by Equation (16) as follows:…”

“…There are a lot of models that describe motor behavior, like the finite element method (FEM) [7,10,[16][17][18][19], d-q reference frame [8][9][10][11][12][20][21][22] and magnetic equation [23,24]. Among these models, the d-q reference frame model provides the optimum combination of analysis time and parameter requirements along with acceptable results from the analysis.…”

Optimization of the rotor geometry of the line-start permanent magnet synchronous motor by the use of particle swarm optimization

“…First component of the penalty term is related to the starting performance of LSPMSM. Regarding to ( Jędryczka et al, 2014) to ensure proper synchronization of LSPMSM the electromagnetic torque at rotor speed about 0.8 of synchronous speed T(s) should be maximized. In studied problem it has been assumed synchronizing torque T(s) should be greater than required value T(s)⩾T z .…”

“…In order to determine the main parameters of LSPMSM i.e. cosφ, η and winding currents, it is necessary to carry out simulations of entire dynamics operation mode ( Jędryczka et al, 2014). The calculations have been executed for rated voltage U ¼ 500 V, load torque equal to T lo ¼ 20 Nm and moment of inertia J ¼ 0.0073156 kg m 2 .…”