Design And Analysis Of Double-sided Linear Primary Permanent Magnet Vernier Motor

With the stable development of macro economy, the urbanization rate is increasing constantly, which not only promotes the development of commercial real estate, but also drives the construction of city infrastructure. In order to display the image of the city and economize on land, large-scale construction of super high buildings are chosen usually. As a necessary device in the modern construction, the elevator is developing rapidly. Although there are various elevators, the elevator used most currently is often driven by electric and adopts steel wire rope traction structure. However, with the increasing height of modern buildings, the shortcomings of traction drive system expose gradually. As a brand-new kind of elevator drive mode, elevators driven by linear motors have received wide attention from scholars domestic and overseas. Primary permanent magnet linear motor is a new type permanent magnet linear motor, in which both the high price magnet and armature winding are located on the short primary mover while the long stator is only made of iron.Hence,it incorporates the merits of high power density and high efficiency of permanent magnet synchronous liner motor and the merits of simple structure,low cost and high reliability of switched reluctance linear motor. It can offer an efficient and inexpensive drive method for long distance drive system.So, it has a good application prospect in this area.Thus, a double-sided linear primary permanent magnet vernier(DSLPPMV) motor is proposed, which works based on the magnetic-geared principle. This motor obtains the advantages of low speed and high thrust force, which is very suitable for long distance situations, such as elevator drive and rail transit.The main research content of this thesis can be summarized as follows: 1. A new DSLPPMV motor is proposed in this thesis, which is very suitable for elevator drive. The basic structure and winding arrangements of the motor are descried firstly. Then, the operation principle of the proposed motor is illustrated by using the equivalent magnetic circuit method. Finally, the nature of low speed and high thrust force of the motor is revealed. 2. Some important parameters of the DSLPPMV motor are analyzed by magnetic equivalent circuit method and optimized by the finite element method(FEM),such as permanent magnet thickness, secondary tooth width and tooth height. Secondly, the current and temperature demagnetization under two different permanent magnetic materials are compared which proves that permanent magnet material is selected appropriately. Finally, series of parameters of the motor are summarized. 3. The static characteristics of DSLPPMV motor are analyzed by using 2D FEM, including the cogging force, no-load flux linkage, no-load EMF and thrust force. And the saturated and unsaturated inductances of DSLPPMV motor are compared. 4. The loss of DSLPPMV motor are analyzed, including the iron loss, eddy current loss of permanent magnet and copper loss, in which the calculation of iron loss namely hysteresis loss and eddy current loss is described in details. And then the general procedure of iron loss calculation by FEM is established. Finally, the efficiency of the motor is calculated according to various loss results. 5. The thermal analysis of DSLPPMV motor is simulated by 3D FEM. The temperature rise of the motor versus heat dissipation coefficient is researched seriously, which establishes the theoretical basis for the study of motor cooling.