Torque Ripple Minimizing of Uniform Slot Machines with Delta Rotor via Subdomain Analysis

Abstract

Since the slot opening is large in the uniform slot machine, the torque ripple generated by overlapping or misaligning with the rotor cavity is remarkably large in the case of interior permanent magnet (IPM) machine. In this work, it is observed that the magnitude of torque ripple depends strongly on the phase difference between air-gap field harmonics: The ripple is minimized when the two dominant harmonic components cancel each other. Based on this fact, a condition is developed to minimize torque ripple by adjusting the q-flux channel width and d-flux barrier width. The torque ripple minimizing solution is found from a level chart made by subdomain time-stepping analysis. Finite element analysis (FEA) also gives a very similar minimizing solution. A prototype machine is manufactured, and its performances are validated through experiments.

High-Speed Design with Separated Tapering for Reducing Cogging Torque and Torque Ripple of a 3 kW Dry Vacuum Pump Motor for the ETCH Process

“…This tapering method in which Lst and Lct, are applied simultaneously is defined as separated tapering. The reason for separating the axis into two on both sides is explained below [2,3]. If tapering is performed only on the existing L ct , it is applied even to areas where tapering is not required.…”

“…This tapering method in which L st and L ct , are applied simultaneously is defined as separated tapering. The reason for separating the axis into two on both sides is explained below [2,3]. Figure 5 shows the process where magnets are pushed inside the rotor during conventional tapering.…”

“…It is important to reduce torque ripple, a major cause of vibration and noise in motor design [1]. Among the causes of torque ripple, there are reasons related to the mechanical structure [2,3]. Research on SRM motors with altered shapes to reduce torque ripple [2], as well as studies on torque-ripple reduction through skewing, is active [3].…”

“…Among the causes of torque ripple, there are reasons related to the mechanical structure [2,3]. Research on SRM motors with altered shapes to reduce torque ripple [2], as well as studies on torque-ripple reduction through skewing, is active [3]. One of the causes of torque ripple is cogging torque.…”

Optimization of a Permanent Magnet Synchronous Motor for e-Mobility Using Metamodels

“…There are various methods for reducing the torque ripple as reported in the contemporary literature, such as changing the shape of the stator, rotor, and shoe, and applying a skew and notch. In [11], the torque ripple was minimized by designing a cavity on the rotor. In [12], the shape of the barrier of the rotor was optimized using a response surface methodology, which is an experimental design method, and a wedge skew was applied to the shoe of the stator to reduce the torque ripple.…”