Winding Switching and Turn Switching in Permanent Magnet Vernier Machines for Wide Speed Range Operation and High Efficiency

Abstract

This paper proposes to turn to switch along with winding switching for high-efficiency of permanent magnet vernier machines (PMVM) during wide speed range operation for electric vehicles application. For winding switching, the three-phase winding of the machine is divided into two sets of windings, namely, winding set A, B, C and winding set X, Y, Z. For turn switching, the number of turns for one set of winding is changed. With the different number of turns for winding set X, Y, Z, the efficiency of the machine can be significantly improved. Initially, the basic electromagnetic characteristics, such as the flux linkage, back electromotive force (EMF), torque, and phase voltages of the machine are investigated using winding switching and turn switching. Then, the output power, torque-speed curve, core losses, efficiency, and power factor of the machine are analyzed in detail using a different number of turns. In addition, the transient effects of winding switching and turn switching have been analyzed. Finally, a control strategy is proposed which combines turn switching and winding switching to ensure high-efficiency of PMVMs during wide speed range operation. A PMVM is designed and driven in accordance with the proposed control strategy (PCS) to show the characteristics of PCS. The PMVM driven with PCS is compared to a recently presented PMVM. The recently presented PMVM is driven by a different control strategy and is analyzed with two different kinds of steel laminations that are general steel (50TW470) and special steel (20JHF1300). INDEX TERMS High efficiency, permanent magnet vernier machine, turn switching, wide speed range, winding switching.

Investigation Study of Multi-Mode Multi-Speed Operation Method for Surface-Mounted Permanent Magnet Synchronous Machines

“…The proposed method has an advantage in terms of flux weakening compared with the other methods. Although it utilizes the highest number of additional switches, the implementation of the single inverter still imparts an advantage in favor of the proposed method over the methods presented in [14]- [19] in terms of cost. Notably, the cumulative/differential switching method for a dual inverter can utilize the voltage boost technique, which increases the available voltage by 1.73 times [16].…”

“…Moreover, it can still be combined with a conventional fluxweakening control by applying a negative Id current [17]. However, this method requires an expensive dual-inverter topology [14]- [19].…”

Operation Method of Non-Salient Permanent Magnet Synchronous Machine for Extended Speed Range

“…However, this scheme utilizes several semiconductor switches. In references [19]- [25], a winding changeover scheme for the wide-speed operation of a PMSM is presented. This scheme showed a high-speed range extension ratio, whereby the four-pole machine speed was increased by approximately 3.6 times.…”

“…This method is based on the winding changeover scheme to reduce the induced back EMF. Unlike the schemes in [18]- [25], it utilizes a conventional three-phase full-bridge inverter topology with an additional six bidirectional switches and provides a speed range extension ratio of 3.83. Because the ready-available inverter topology was used, it is possible to decrease the drive cost and its control complexity.…”

Wide-Speed Range Operation of PM Vernier Machines Using Wye and Wye-Delta Winding Configurations

“…However, the efficiency of the machine was low during this operation. In [19], turn switching, and winding switching have been proposed for PMVMs to improve efficiency during wide-speed range operation for EV applications. This technique improved the low-efficiency problem associated with that of [18]; however, the tradeoff was increased cost due to the additional eight switches and dual-inverter topology.…”