Design Aspects and Performance Evaluation of Pole-Phase Changing Induction Machines

Abstract

Pole-phase changing induction machines (IMs) offer the capability to extend the torque-speed envelope compared to their fixed pole-phase counterparts. Dynamic pole-changing can achieve higher torque levels at lower speeds, utilizing higher pole numbers, and extended flux-weakening range with lower pole-number operations. This paper investigates the design impact on the optimum pole-phase changing behavior and respective split of the operating region to different pole-phase operations. Additionally, the improvement in terms of the overall torque per ampere capability and efficiency is illustrated. For the purposes of the analysis, two different IMs with wound independently-controlled stator coils (WICSC) and different original pole numbers are evaluated in an effort to quantify the extent of the benefits of pole-phase changing. These geometries correspond to machines that were originally designed with 2- and 6 magnetic poles, respectively. It is shown that, in the case of the original 2-pole WICSC machine, shifting to a higher pole number is notably beneficial in terms of efficiency in a significant part of the operating region, whereas in the original 6-pole, both higher and lower pole numbers significantly enhance the overall torque capability and efficiency. The results highlight the notable benefits of pole-phase changing IMs and offer deep insight towards the derivation of standard design guidelines for these machines.

Determining the optimal steps of the number of fields with variable windings

“…A comparison of two-speed motors with one winding and two separate windings of the same power shows that twowinding motors are more expensive than single-winding motors -electrical steel is saved by 30-40% and copper by 40-50%, in addition to the motor useful work coefficient and cosph decrease by 10-15% on average. One of the most common schemes of the variable number of poles is the Dalander scheme, based on different basic schemes, variable number of poles have been developed for different numbers of stator phases and pole ratios [8][9][10][11]. At the department of "Electrical supply" of the Tashkent State Technical University, the scientific group headed by professor M.Bobojanov developed circuits with a variable number of poles.…”

Comprehensive Multidisciplinary Electric Vehicle Modeling: Investigating the Effect of Vehicle Design on Energy Consumption and Efficiency

“…On the other hand, the induction machine (IM) provides comparable torque and performance when used in PMSMs, especially at high speeds [19,20]. The IM's advantages include the absence of magnets, a robust structure, and cost-effectiveness [21][22][23][24]. With the aim of achieving high power density, we selected the PMSM as the focus of this study [25].…”