In this paper, a wireless shaded-pole induction motor (SPIM) is proposed and implemented, which artfully integrates wireless power transfer (WPT) into a single-phase SPIM to achieve the first wireless AC motor. Prominently, there is no controller at the SPIM side, as the controlling process is fully conducted at the transmitter side. Meanwhile, there is no need to specially design the motor, as all existing SPIMs can readily be used. The key is to propose a self-driving circuit in the receiver, which can provide variable-voltage variable-frequency control of the SPIM. As a result, the proposed wireless SPIM takes the definite advantages of electrocution-free and totally sealable. A 110-W prototype has been built for experimental verification. It can offer wireless speed control from 486 rpm to 1330 rpm with the transfer distance of 30 mm and the transmission efficiency of 86.2%.

In this paper, a novel double-rotor flux-switching permanent-magnet (DR-FSPM) motor is proposed for electric vehicles with the capability of magnetic differential (MagD). The key is to introduce a new set of winding which magnetically couples with the two rotors of the DR-FSPM motor in such a way that the magnetic coupling winding field can interact with the PM fields in the two rotors. Hence, the differential torque can be generated between wheels to achieve accurate cornering during vehicle steering. Consequently, the proposed system can offer higher efficiency and compactness than the conventional mechanical differential system, while provide higher reliability and safer operation than the electronic differential system. The operation principle and performances of the proposed DR-FSPM motor are thoroughly analyzed by finite element analysis while the proposed MagD system is also evaluated with system simulation. Finally, the motor prototype is built while the prototype and MagD system are tested for experimental verification.

Traditionally, domestic induction heating (IH) is designed to heat the ferromagnetic (FM) pan. However, it is incompetent to heat the non-FM (NFM) pan since the small equivalent resistance of the pan will easily result in overcurrent on the inverter. Inspired by the compensation network in the wireless power transfer (WPT), the series–parallel resonance (SPR) network with a relay switch is newly integrated into the IH technology to develop a dual-resonant topology-reconfigurable inverter for all-metal IH. The proposed system can be purposely configured to a half-bridge series resonant inverter with the pulse width modulation (PWM) to heat the FM pan, or a full-bridge SPR-based inverter with the phase shift control (PSC) to heat the NFM pan, respectively. Moreover, the output–input current gain of the SPR network equals the heating-coil quality factor, thereby readily eliminating the overcurrent issue of the inverter. For exemplification, a 1-kW prototype has been built with system efficiencies of 94.32% and 91.05% for heating FM and NFM pans, respectively. Finally, the proposed system can be evolved to achieve automatic load detection and impedance matching to ensure uninterrupted resonance. Both the calculated and measured results are given to validate the flexibility and feasibility of the proposed system.

In this article, a wireless resolver is proposed and implemented for wireless switched reluctance (SR) motors, which can detect the rotor position and transfer the information to the primary side without involving any battery storage or active components at the secondary side. The key is to integrate wireless power transfer (WPT) into a variable reluctance resolver to detect and transmit the rotor position. Compared with previous wireless SR motors adopting the Hall effect position encoder and Bluetooth communication, the robustness is highly improved, and the communication delay caused by the connection interval can be solved. Therefore, the proposed system takes the definite advantages of better dynamic performance and sealability. Besides, there is no need to specially design the SR motor, as all existing SR motors and other similar kinds of motors can readily employ this wireless resolver. An experimental prototype has been built for verification, which works well from 100 to 900 rpm with 20 mm WPT distance, and the additional power for position detection can be limited to 1.05 W while the motor consumes 54 W.

This article presented a single-phase shaded-pole induction motor (SPIM) system, which aims to work in an isolated environment. Compared with the previous wireless SPIM, this system employs less controlled switches and can work at full-resonant condition, while retaining the merit of secondary controllerless. The key is to employ a half-bridge inverter and a proper dual-frequency resonant network; thus, only two controlled switches are adopted at the motor side. Since the SPIM is purposely designed with a dual-stator winding, the system robustness and efficiency can be significantly improved. In this article, simulation has been conducted to verify the system's feasibility and self-drive ability. Meanwhile, a 30-W prototype has been built for the experimental verification, and the results show that this motor can achieve flexible speed control with the transfer distance of 20 mm and the transmission efficiency of 77%.