A new split-winding doubly salient permanent magnet (DSPM) motor drive is proposed. This DSPM motor drive offers the advantages of high power density, high efficiency, and wide speed range. The corresponding operation, analysis, implementation, and experimentation are successively presented. Finally, experimental results are used to confirm that the proposed DSPM motor drive offers high efficiency over a wide output power range, exhibits good dynamic performance, and extends the constant-power operation range significantly.

The inductance characteristic of doubly salient permanent magnet (DSPM) motors is the basis of design, analysis, and control of the motor. Due to the nonlinearity and doubly salient structure of the motor, this characteristic is a function of not only the rotor position, but also the strengthening and weakening actions of the armature flux to the permanent magnet (PM) flux, which makes the measurement of inductance difficult. This article proposes new methods for the measurement of the motor inductance for any rotor positions and level of excitation. The methods are applied to the two newly proposed DSPM motors and the results are compared with those obtained by finite element analysis. It is shown that the proposed peak value method can correctly reflect the influence of the strengthening and weakening actions of the armature flux to the PM flux on the inductance of DSPM motors.

：定子永磁型无刷电机是一类永磁体和电枢绕组均位于 定子的新型永磁无刷电机，可方便地对永磁体和电枢绕直接冷却以控制其温度，并易于通过“永磁+电励磁”实现对电机气隙磁场的直接控制，从而获得无刷电机的宽范围调速；凸极转子既无永磁体也无绕组，结构简单可靠，适合高速运行；该电机兼具功率密度高、效率高、容错性能好、控制灵 活等特点。该文介绍了定子永磁型无刷电机的基本结构与工作原理，总结了它们的共性规律和个性差别，对其分析设计方法、控制策略等关键技术进行综述，讨论了多种磁通调节 方案和容错控制策略，分析了该电机系统在电动汽车、飞轮储能、轨道交通等领域应用的可行性和潜力，最后对该电机系统的主要研究方向进行了展望。

This article presents the general requirement of traction motor drives. The differences between traction motors and industrial motors are compared. The classification of traction motors is given and the characteristics of each type of motors namely DC motor, induction motor, permanent magnet (PM) motor, PM hybrid motor and switched reluctance motor are discussed and evaluated. The newly developed stator-PM machines are also introduced. The design consideration of traction motors is described with emphasis on sizing equation, selection of electric and magnetic loadings, speed ratings and etc. Moreover, system level consideration in traction motor design, including single or multi-motor configurations, fixed- or variable-gearing transmissions, geared or gearless, voltage level and etc., are also presented. Power devices and power converters for traction motor drives are discussed and evaluated. Control strategies for traction motor drives, including field-oriented control (FOC), direct torque control (DTC), artificial intelligent control (AIC), and position-sensorless control (PSLC), are presented and compared.

This paper gives a comprehensive review of the state of the art of wind energy conversion systems (WECS) and technologies, with an emphasis on wind power generator and control. First, different types of common WECSs are classified according to their features and drive train types. The WECSs are compared on the basis of the volume, weight, cost, efficiency, system reliability and fault ride through capability. The maximum power point tracking (MPPT) control, which aims to make the generator speed meet an optimum value to ensure the maximum energy yield, plays a key role in the variable speed WECSs. A comprehensive review and comparison of the four most popular MPPT control methods are carried out and improvements for each method are presented. Furthermore, the latest development of wind energy conversion technologies is introduced, such as the brushless doubly fed induction generator (BDFIG), the stator permanent magnet synchronous generators, the magnetic-geared generators, dual power flow WECS with the electrical variable transmission (EVT) machine, and direct grid-connected WECS. Finally, the future trends of the technologies are discussed.