Design and Analysis of New Modular Stator Hybrid Excitation Synchronous Motor

Hybrid excitation motor is a combination of permanent magnet motor and electric excitation motor,which can flexibly adjust the air gap magnetic field.At present,the traditional silicon steel sheet core material is widely used,but this material limits the further reduction of stator iron loss.In this paper,a new type of hybrid excitation synchronous motor with modular stator structure based on amorphous alloy material is proposed.The design power is 1kW,and the speed is 3000rpm.By placing the armature winding and electric excitation winding in the stator slot,the slip ring and brush are avoided,and the reliability of the motor is improved.The rotor adopts staggered magnetic pole structure,which has strong flux adjusting ability.The core loss is greatly reduced by using amorphous alloy.Firstly,the structure and working principle of the new motor are given;Secondly,the size parameters of the motor are given,and the principle of flux adjustment is verified and analyzed by three-dimensional finite element(3D-FEM);Finally,through theoretical analysis of the influence factors of the magnetic adjustment ability and 3D-FEM finite element computation,the flux adjustment ability and the torque lifting at low speed are verified,and the advantages of the motor are verified.

Cooling System Design and Thermal Analysis of Modular Stator Hybrid Excitation Synchronous Motor

Hybrid excitation synchronous motor has the advantages of uniform and adjustable electromagnetic field, wide speed range and high power density. It has broad application prospects in new energy electric vehicles, wind power generation and other fields. This paper introduces the basic structure of hybrid excitation motor with modular stator, and analyzes the operation principle of hybrid excitation motor. The cooling structure of the water-cooled plate is designed, and the effects of the thickness of the water-cooled plate and the number of water channels in the water-cooled plate on the heat dissipation capacity of the water-cooled plate are analyzed by theoretical and computational fluid dynamics methods. The effects of different water cooling plate structures on water velocity, pressure drop, water pump power consumption and heat dissipation capacity were compared and analyzed. The influence of different inlet flow velocity on the maximum temperature rise of each part of the motor is analyzed, and the temperature of each part of the motor under the optimal water flow is analyzed. The influence of the traditional spiral water jacket cooling structure and the water-cooled plate cooling structure on the maximum temperature rise of the motor components is compared and analyzed. The results show that the water-cooled plate cooling structure is more suitable for the modular stator motor studied in this paper. Based on the water-cooled plate cooling structure, the air-water composite cooling structure is designed, and the effects of the air-water composite cooling structure and the water-cooled plate cooling structure on the maximum temperature rise of each component of the motor are compared and analyzed. The results show that the maximum temperature rise of each component of the motor is reduced under the air-water composite cooling structure.

Equivalent circuit and characteristic simulation of a brushless electrically excited synchronous wind power generator

A brushless electrically excited synchronous generator （BEESG） with a hybrid rotor is a novel electrically excited synchronous generator. The BEESG proposed in this paper is composed of a conventional stator with two different sets of windings with different pole numbers, and a hybrid rotor with powerful coupling capacity. The pole number of the rotor is different from those of the stator windings. Thus, an analysis method different from that applied to conventional generators should be applied to the BEESG. In view of this problem, the equivalent circuit and electromagnetic torque expression of the BEESG are derived on the basis of electromagnetic relation of the proposed generator. The generator is simulated and tested experimentally using the established equivalent circuit model. The experimental and simulation data are then analyzed and compared. Results show the validity of the equivalent circuit model.

Research on a direct torque control for an electrically excited synchronous motor drive with low ripple in flux and torque

The electrically excited synchronous motor(ESM)has typically small synchronous inductance values and quite low transient values because of the damper windings mounted on the rotor.Therefore,the torque and stator flux linkage ripples are high in the direct torque control(DTC)drive of the ESM with a torque and flux linkage hysteresis controller(basic DTC).A DTC scheme with space vector modulation(SVM)for the ESM was investigated in this paper.It is based on the compensation of the stator flux link-age vector error using the space vector modulation in order to decrease the torque and flux linkage ripples and produce fixed switching frequency under the principle that the torque is controlled by the torque angle in the ESM.Compared with the basic DTC,the results of the simulation and experiment show that the torque and flux linkage ripples are reduced,the maximum current value is decreased during the startup,and the current distortion is much smaller in the steady-state under the SVM-DTC.The field-weakening control is incorporated with the SVM-DTC successfully.

Overview and Development of Variable Frequency AC Generators for More Electric Aircraft Generation System

With the development of more electric aircraft(MEA),higher demands for electrical energy are put forward in generation systems.Compared to constant frequency AC(CFAC)generation systems,the constant speed drive(CSD)is eliminated and integrated starter/generator(SG)can be realized in variable frequency AC(VFAC)generation systems.In this paper,an overview of VFAC generators for safety-critical aircraft applications is presented,with a particular focus on the key features and requirements of candidate generators and the starting control strategies.Wound rotor synchronous machines(WRSMs)are typical generators used in VFAC generation systems so far.Meanwhile,hybrid excitation synchronous machines(HESMs)and cage-type induction machines are promising candidates for VFAC generation systems.The generation operation of WRSM is relatively mature,however,the SG technology of WRSM is still full of challenges.As one of the most important issues,the starting excitation methods of WRSM are summarized.An HESM-based VFAC SG system is proposed and developed in this paper.The experimental results show that the starting mode,transition mode and generating mode of the VFAC SG system are realized.The continuous progress of VFAC generation system makes great contributions to the realization of MEA.