Due to the high efficiency, high power density and high flexibility for maneuvering and docking, electric propulsion systems for marine propulsion attract more and more attention in recent year. Generally, the motor for marine propulsion operates at a low speed which implies that the size of the motor tends to be large. By eliminating the transmission gear, the vernier permanent-magnet (PM)...
Low-speed high-torque machines are being increasingly used in various applications such as electric vehicles, wind-power generation, electric vessels, industrial robots, and home appliances, because they can offer direct-drive operation, which avoids the inconveniences of mechanical gearboxes. The magnetic geared permanent magnet (MGPM) machine, which works similar to an electrical machine...
In recent years, due to the highly variable cost of rare-earth permanent magnet(PM) and requirement for more efficient motor, PM-assisted synchronous reluctance machine(PMAREL) have attracted increasing attention and become one of the research highlights in the motor field. Generally, the PMAREL machines are characterized by a complex rotor structure, where multi flux barriers are set to...
Interior permanent magnet synchronous machine (IPMSM) have been widely used in many areas compared with the conventional motors for their advantages, such as high torque, high power, widely variable speed range and so on. Theoretically, IPMSM can be designed with an infinite speed range for constant power operation by utilizing flux weakening control method. But practically, in order to...
Recently, high-speed electrical machines are being used at an increasing rate owing to the numerous advantages of high-speed compressors such as high efficiency, simple structure, high power density, and small size. Researchers have proposed various electromagnetic designs for high-speed permanent magnet (PM) machines. However, for high-speed PM machines, mechanical stresses are generated in...
PM linear machine is an important category of PM machine, which is suitable for rail transit. The existence of the end effect will cause the unbalanced back-EMF, which can enlarge the ripple of the thrust. A novel linear vernier mover-PM (LVMPM) machine will be proposed in this paper. It is economical to be used in long distance. The characteristics of the proposed machine are analyzed by...
Rare-earth permanent magnet (PM) machines have been widely recognized as a promising candidate for EV propulsion due to their merits of high power density and high reliability. In recent years, the price of rare-earth PM materials have been experienced significant increase and fluctuations which increased the manufacturing cost of rare-earth PM motor obviously. In this paper, a new...
The flux characteristics of a single-phase tubular permanent magnet linear motor (TPMLM) is analyzed with magnetic equivalent circuit (MEC) method in this paper. The flux linkage of the proposed single-phase TPMLM is generated by the permanent magnets and the bread type windings. The magnetic lines of flux travel through the stator yoke, the stator sleeve, air gap, and the mover to form a...
Recently, integrated motor propulsors (IMPs) have been under extensive research and development because of the numerous advantages of underwater propulsion for vehicles. IMPs require minimized torque ripple for smooth and quiet operation when used in undersea vehicles or unmanned submarines. Thus, torque ripple reduction should be considered in the design stage. In the IMP case, a permanent...
This paper presents a novel 16/12 outer module rotor-type switched reluctance machine. Unlike conventional structures, the rotor of the proposed structure includes a series of discrete module, and every outer module rotor is U-shaped structure and has two rotor pole. Each phase winding is composed of two series coils wrapped on two stator teeth. The short flux paths can be generated by excited...
In order to achieve high efficiency over wide-speed operation, variable flux memory motor (VFMM) has been proposed. This new class of motor can control the magnetization state by applying direct-axis (d-axis) current pulses. When designing VFMM, it is important to study nonlinear magnetization state considering the electrical constrains, since the PM magnetization strength must be controlled...
Ferrite-assisted synchronous reluctance motors (FASRM) provide high torque density and a wide range operation speeds for many applications, ranging from electric vehicle and electric home appliance. However, the main drawback of the FASRM is the high torque ripple. This paper is to propose a method of reducing total ripple by changing the opening angle of flux barrier. The key of this method...