Research on the Temperature Field of High-Voltage High Power Line Start Permanent Magnet Synchronous Machines with Different Rotor Cage Structure

Abstract

For line start permanent magnet synchronous machines (LSPMSMs), the eddy current loss in the rotor, which has of significant effects on rotor working temperature, may cause thermal demagnetization to permanent magnet. Therefore, this paper addresses an investigation on the temperature distribution in LSPMSM based on a 6 kV, 315 kW prototype with solid starting cage bar. Firstly, the loss distributions, obtained from a 2-D transient electromagnetic field calculation, are determined as the distributed heat source in thermal analyses. Then, the fluid-thermal coupled analyses are performed, by which the temperature distributions in the machine are determined. Meanwhile, the calculated motor performance is verified via comparison with the measured results. The calculation results show that the temperatures in the rotor core and permanent magnets are relatively high. To find the solution for reducing the rotor working temperature, a rotor air slot structure was proposed in this analysis. The theoretical calculation indicates that the rotor working temperature reduction is obvious with the rotor air slot in the machine. Therefore, the operating situation of solid rotor LSPMSM could be improved effectively with the proposed rotor thermal solution, which also benefits the machine reliability and safety.

Influence of Single/Dual Ventilation Path on Fluid Field and Temperature Field of HVLSSR-PMSM with Air-Cooled Hybrid Ventilation Systems

“…Energies 2018, 11, 1343 4 of 15 (1) The influences of displacement current and the skin effect of the stator windings are ignored.…”

“…The flow of air in the motor needs to satisfy the energy conservation equation, mass conservation equation, and momentum conservation equation. The mathematical equations of the fluid-thermal coupling of the motor are shown as follows [1]: To calculate the flow of air in a turbulent state, the fluid flowing is calculated by the standard k-ε model [1]:…”

“…To calculate the flow of air in a turbulent state, the fluid flowing is calculated by the standard kε model [1]:…”

“…The high -voltage line -start solid rotor permanent magnet synchronous motor (HVLSSR-PMSM) has attracted much attention as a candidate for heavy duty applications such as pumps for cooling system in power plants, large air compressor for mines, and fans, due to their inherent advantages of high efficiency, high power factor, high starting torque, and low starting current [1,2]. In the actual operation of solid rotor permanent magnet (PM) synchronous motor, the rotor eddy current loss is considerably large.…”

Multifield Calculation and Analysis of Excitation Winding Interturn Short Circuit Fault in Turbo-Generator

“…It is vital to accurately judge the generator aging by calculating the temperature distribution under main insulation normal operation and fault operation. In addition, the calculation and analysis of temperature fields are often applied in research fields, such as induction motors and permanent magnet motors [29][30][31][32][33]. Therefore, the change in generator temperature and stress fields after fault are important fault features that are worthy of study.…”