Performance improvement of 36‐slot 6‐terminal induction motor drive using pole phase modulation with higher slot per pole per phase

Abstract

SummaryElectric vehicles (EVs) are getting imperative with passing time due to depleting fossil fuel resources and worsening pollution scenario. Induction motors (IMs) are a promising alternative to the conventional drive systems due to its inherent advantages. However, an efficient geared operation similar to internal combustion engine (ICE) vehicles is essential for wider adoption of the IM drive in EVs. Pole phase modulation technique helps achieve variable speed and torque combinations analogous to geared operation in IM. Performance of the IM drive can be improved by altering the stator winding configuration to achieve high slot per pole per phase, lesser leakage reactance, and lower DC link voltages. A single layered distributed winding is proposed in this work to achieve the above objectives. The proposed winding is first simulated using Maxwell‐2D and Finite Element Analysis (FEA) that are performed to understand the performance characteristics of IM drive with proposed winding scheme. The hardware implementation of the similar setup is done, and the tests are carried out to validate the simulation results. A 3HP, 36‐slot, 6‐terminal IM was fabricated for this purpose which was fed by the microcontroller based 6‐leg inverter for stator winding excitation. This helps to achieve low pole (6‐phase/2‐pole) and high pole (3‐phase/4‐pole) modes of operation to simulate a 2‐geared ICE performance. The study proved that high torque driving requirements can be fulfilled by a low pole operation while cruising requirements are met with a high pole operation. It also showed that the constant power region increases along with the efficiency contours plotted against the torque‐speed characteristics.