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This study aims to propose criteria for both optimal-shape and magnetizer-system designs to be used for a high-output spoke-type motor. The study also examines methods of reducing high-cogging torque and torque ripple, to prevent noise and vibration.

The optimal design of the stator and rotor can be enhanced using both a response surface method (RSM) and finite element method (FEM). In addition, a magnetizer system is optimally designed for the magnetization of permanent magnets for use in the motor.

The criteria not only improve performance but also reduce manufacturing costs. The criteria are verified FEM together with an RSM. These methods are used to optimize the stator and rotor shape and the magnetization system. These methods allow us to produce an efficient system for mass production of the motor.

This study proposed a design method that uses rare earth magnets in a system to replace the spoke-type IPM. To verify the optimal design, torque characteristics were analysed using FEM and RSM. Excellent results were achieved regarding the reduction of cogging torque and torque ripple. In addition, the design of the magnetizer enables a cost-effective mass production system for the motor.

The purpose of this paper is to propose a permanent magnet-assisted synchronous reluctance machine (PMASynRM) using ferrite magnets with the same power density as rare-earth PM synchronous motors used in Toyota Prius 2010.

A novel rotor structure with rectangular PMs is discussed with respect to the demagnetization of ferrite magnets and mechanical strength. Some electromagnetic characteristics including torque, output power, loss and efficiency are calculated by 2D finite element analysis.

The results of the analysis show that a high power density and high efficiency for PMASynRM can be achieved using ferrite magnets.

This paper proposes a novel rotor structure of PMASynRM with low-cost ferrite magnets that achieves high power density as permanent machines with rare-earth PMs.

Power‐electronic systems have been playing a significant role in the integration of large‐scale wind turbines into power systems due to the fact that during the past three decades power‐electronic technology has experienced a dramatic evolution. This second part of the paper aims to focus on a comprehensive survey of power converters and their associated control systems for high‐power wind energy generation applications.

Advanced control strategies, i.e. field‐oriented vector control and direct power control, are initially reviewed for wind‐turbine driven doubly fed induction generator (DFIG) systems. Various topologies of power converters, comprising back‐to‐back (BTB) connected two‐ and multi‐level voltage source converters (VSCs), BTB current source converters (CSCs) and matrix converters, are identified for high‐power wind‐turbine driven PMSG systems, with their respective features and challenges outlined. Finally, several control issues, viz., basic control targets, active damping control and sensorless control schemes, are elaborated for the machine‐ and grid‐side converters of PMSG wind generation systems.

For high‐power PMSG‐based wind turbines ranging from 3 MW to 5 MW, parallel‐connected 2‐level LV BTB VSCs are the most cost‐effective converter topology with mature commercial products, particularly for dual 3‐phase stator‐winding PMSG generation systems. For higher‐capacity wind‐turbine driven PMSGs rated from 5 MW to 10 MW, medium voltage multi‐level converters, such as 5‐level regenerative CHB, 3‐ and 4‐level FC BTB VSC, and 3‐level BTB VSC, are preferred. Among them, 3‐level BTB NPC topology is the favorite with well‐proven technology and industrial applications, which can also be extensively applicable with open‐end winding and dual stator‐winding PMSGs so as to create even higher voltage/power wind generation systems. Sensorless control algorithms based on fundamental voltages/currents are suggested to be employed in the basic VC/DPC schemes for enhancing the robustness in the entire PMSG‐based wind power generation system, due to that the problems related with electromagnetic interferences in the position signals and the failures in the mechanical encoders can be avoided.

This second part of the paper for the first time systematically reviews the latest state of arts with regard to power converters and their associated advanced control strategies for high‐power wind energy generation applications. It summarizes a variety of converter topologies with pros and cons highlighted for different power ratings of wind turbines.

This paper aims to propose a spoke-type fractional-slot concentrated windings (FSCW) PM machine for EVs driving system to improve torque density. To further improve electromagnetic performance, the multi-objective optimization design is processed based on response surface (RS) model and simulated annealing cuckoo search (SA-CS) algorithm.

The spoke-type FSCW PM machine is designed and optimized to meet the requirement of EVs driving system. First, a spoke-type FSCW PM machine is designed and some of key parameters are obtained based on equivalent magnetic circuit (EMC) method. Then, the RS model and modified SA-CS algorithm are proposed to obtain higher torque, lower torque ripple and higher efficiency.

After verification by finite element method for no-load and load performance, the optimal machine has higher torque density, lower torque ripple and higher efficiency compared with initial machine. Finally, a 20 kW prototype is manufactured and tested to verify the validity of the proposed optimization design method.

This paper designs a high torque density spoke-type FSCW PM machine, which is superior for EVs driving system. Meanwhile, a novel modified SA-CS algorithm is applied to the field of electrical machine multi-objective optimal design.

This paper proposes a spoke-type fractional-slot concentrated windings (FSCW) permanent magnet (PM) machine for special vehicle driving systems to obtain higher torque and power density, high efficiency and wide field-weakening range. To enhance the efficiencies of multi-objective optimization processes, the respond surface (RS) method and black-hole (BH) algorithm are used.

The spoke-type FSCW PM machine is optimized to meet the requirements of the special vehicle driving system. The combination of the RS and BH algorithm is used to obtain high torque, low torque ripple and high efficiency.

The optimal spoke-type PM machine is obtained, and it has higher torque density, lower torque ripple, cogging torque and wider magnetic field weakening range. Finally, a 15-kW prototype machine is fabricated and tested to verify the results of the optimization method and finite-element analysis.

This paper designs a high torque density and efficiency spoke-type FSCW PM machine, which is superior for special vehicle driving systems. Meanwhile, the RS model combined with BH algorithm is applied to the field of electrical machine multi-objective optimal design.