Numerical Simulation of the Line-Start Permanent Magnet Synchronous Motor

Abstract

This thesis reports on a detailed numerical simulation of a line-start permanent magnet synchronous motor (LSPMSM) using two-dimensional finite element analysis (FEA) in ANSYS Maxwell 2D. The main goal is to show that adding Y33 hard-ferrite permanent magnets to the rotor of a standard 3 kW, 4-pole, 400 V, 50 Hz asynchronous induction motor allows it to run synchronously at 1500 RPM. This design meets the IEC IE4 Super Premium efficiency class, which is a standard set by the International Electrotechnical Commission that indicates very high energy efficiency for electric motors. This study simulated and compared two motor models: The baseline 000 ASM (Asynchronous Induction Motor) was compared with the new 001 SM (Line-Start Permanent Magnet Synchronous Motor), which uses Bestway Magnet Y33 ferrite permanent magnets in an interior permanent magnet (IPM) setup measuring 40 mm by 10 mm. The 001 SM reached synchronisation at a steady speed of 1499.3 RPM with a slip of 0.076%. It delivered a peak starting torque of 167.26 N·m, which is 34.6% higher than the baseline. It's steady-state efficiency was 94.26%, compared to 88.66% for the baseline ASM, a 5.60 percentage point improvement, meeting the IE4 Super Premium efficiency class. A key comparison was made between Y33 Ferrite and Neodymium-Iron-Boron (NdFeB) permanent magnets in the same LSPMSM design. The NdFeB simulation failed to synchronise. due to magnetic locking caused by a large negative braking torque of −406.2 N·m, which is 4.37 times higher than with ferrite. These results show that using Y33 ferrite magnets is essential for this line-start application. The finite element mesh had 2088 triangular elements for the 001 SM and 2530 elements for the 000 ASM. Both models used one-quarter symmetry and a time step of 0.0001 seconds over a 1.0-second transient.