Loss analysis of line start permanent magnet synchronous motor with Time-Stepping Finite Element Method

In order to analyze the loss of Line Start permanent magnet (LSPM) motor, the loss calculation model, which is based on field-circuit-motion coupled Time-Stepping Finite Element Method (T-S FEM), are established in this paper. Taking a 22kW LSPM motor as an example, the iron losses and rotor copper loss are calculated under different supply voltage and load conditions. It is found that, under no-load condition, iron loss increases with an increasing voltage but rotor copper loss firstly decreases and then increases. Meanwhile, under rated voltage condition, iron loss basically remains constant as the load increasing, however, the rotor copper loss with rated load condition may be 4 times of the one with no-load condition, close to 1 % of rated output power.