Based on the results of the previous studies of other scholars and with the references of historic literature,this paper discusses the yoke finials of chariots of the Shang and Zhou Dynasties. At first,the yoke finial...Based on the results of the previous studies of other scholars and with the references of historic literature,this paper discusses the yoke finials of chariots of the Shang and Zhou Dynasties. At first,the yoke finials of different types are analyzed and classified by nomenclatural and typological methods,then the horse fittings and yoke finials are distinguished. The systematic study to the chariot yoke finials makes us have deeper understanding to the chariot system in the pre-Qin periods.展开更多
In this paper, a novel split-winding doubly salient permanentmagnet (DSPM) motor is proposed and the theoretical and experimental studies on the magnetic field, static characteristics and control strategy of this moto...In this paper, a novel split-winding doubly salient permanentmagnet (DSPM) motor is proposed and the theoretical and experimental studies on the magnetic field, static characteristics and control strategy of this motor are carried out. The steady-state and dynamic models are presented and the output power equation is derived. The feasibility of extending the operation range of the DSPM motor by using split-windings is proved. The finite element method is used to analyze the magnetic field, in which the leakage flux outside the stator circumference is taken into account. Based on the operation principle and the static characteristics of the motor, the control strategy and scheme are developed and implemented in a microcomputer-based controller. According to the features of the 4-phase 8/6-pole DSPM motor, a half-bridge power converter without neutral is adopted to reduce the number of power devices and to eliminate the problem of voltage unbalance in the split capacitors. The experimental results on the prototype machine not only verify the theoretical analysis, but also show that the proposed DSPM motor drive possesses good steady-state and dynamic performances, offering high efficiency over wide power range, and that the split-winding topology can effectively extend the operation range of the DSPM motor.展开更多
文摘Based on the results of the previous studies of other scholars and with the references of historic literature,this paper discusses the yoke finials of chariots of the Shang and Zhou Dynasties. At first,the yoke finials of different types are analyzed and classified by nomenclatural and typological methods,then the horse fittings and yoke finials are distinguished. The systematic study to the chariot yoke finials makes us have deeper understanding to the chariot system in the pre-Qin periods.
基金This work was supported by the National Natural Science Foundation of China (Grant No. 59507001) .
文摘In this paper, a novel split-winding doubly salient permanentmagnet (DSPM) motor is proposed and the theoretical and experimental studies on the magnetic field, static characteristics and control strategy of this motor are carried out. The steady-state and dynamic models are presented and the output power equation is derived. The feasibility of extending the operation range of the DSPM motor by using split-windings is proved. The finite element method is used to analyze the magnetic field, in which the leakage flux outside the stator circumference is taken into account. Based on the operation principle and the static characteristics of the motor, the control strategy and scheme are developed and implemented in a microcomputer-based controller. According to the features of the 4-phase 8/6-pole DSPM motor, a half-bridge power converter without neutral is adopted to reduce the number of power devices and to eliminate the problem of voltage unbalance in the split capacitors. The experimental results on the prototype machine not only verify the theoretical analysis, but also show that the proposed DSPM motor drive possesses good steady-state and dynamic performances, offering high efficiency over wide power range, and that the split-winding topology can effectively extend the operation range of the DSPM motor.
