The Influence of Stator Winding Turns on the Steady-State Performances of Line-Start Permanent Magnet Synchronous Motors

Abstract

The variation of stator winding turns will directly affect the key parameters of a motor, such as winding resistance and winding reactance, which further affect the steady-state performance of the motor. In order to get excellent steady-state performance from line-start permanent magnet synchronous motors (LSPMSMs) under different load powers, taking an 11 kW LSPMSM as an example, the finite element method (FEM), combined with the steady-state phasor diagram and torque angle characteristic, are used in this paper for the optimal design of the stator winding turns of the prototype. The correctness of the model is verified by comparing the experimental data with the calculated data. First, the influences of different stator winding turns on the no-load, back-induced electromotive force (EMF), as well as on inductance and overload ability are studied, and the variation mechanism is obtained. In addition, from the perspective of the torque angle characteristic, the influence of the change in synchronous inductance caused by the number of turns on the steady-state power angle is studied. Second, the variation of the current and power factors with turn number is obtained by studying the steady-state power angle and end voltage. Based on the coupling relationship between the no-load back EMF and the power angle, the mechanism of non-linear variation of current and power factor is revealed. Finally, the variation of the number of turns on the core loss and eddy current loss is analyzed under various operating conditions, and the variation mechanism is revealed, based on the armature reaction theory.

Optimization of Low-Power Line-Start PM Motor Using Gray Wolf Metaheuristic Algorithm

“…Changes in the phase current in the function of load torque depends on values of U/E, where U is the phase voltage and E0 is back-inducted EMF. A detailed analysis of these phenomena is presented in [27]. Measurements of the prototype were performed in case of supplying by rated value of line voltage equal V N = 400 V. The influence of the load torque on the motor functional parameters, as a motor efficiency power factor, as well as the phase current, was examined.…”

“…Changes in the phase current in the function of load torque depends on values of U/E, where U is the phase voltage and E 0 is back-inducted EMF. A detailed analysis of these phenomena is presented in [27]. Table 4 contains a comparison of the functional parameters in steady-state operation for the primary induction motor and line-start permanent magnet synchronous motor for constant load torque Tl equal rated torque.…”

Parametric Analysis for Performance Optimization of Line-Start Synchronous Motor with Interior Asymmetric Permanent Magnet Array Rotor Topology

“…Ψ qr = L qr i dr + L mq i qs (10) The coupling between the electrical system and the mechanical system is represented by the torque equation and the mechanical equation. The electromagnetic torque T el developed by the motor can be expressed as:…”

“…Yet, the proper design of cage winding and the magnets is essential, as the magnets produce the breaking torque that lowers the motor's starting torque and prolongates the motor starting; however, their improper design results in failure of motor synchronization [5][6][7][8][9]. Not only are the magnets responsible for motor operating regimes, starting and steady-state; the stator winding turns also affect the winding resistance, current and the power factor [10]. Another aspect of motor operation is the material of the squirrel cage winding, which is usually aluminum or copper that affects the motor starting and the temperature distribution [11].…”

Line-Start Synchronous Motor a Viable Alternative to Asynchronous Motor

“…Consequently, the copper losses in rotor winding are nullified. The design of the LSSPMM, influence of the various motor parameters like the number of the stator winding turns, rotor configuration or voltage unbalance, on the operating characteristics of the motor have been the subject of investigation during recent years [1]- [10]. The other authors focus on the cogging torque reduction and improvement of the motor performance during starting and at the steady-state operation [11]- [14].…”