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|Title: ||A 2D variable reluctance planar motor|
|Authors: ||Pan, Jianfei|
|Subjects: ||Planar transistors|
Hong Kong Polytechnic University -- Dissertations
|Issue Date: ||2007 |
|Publisher: ||The Hong Kong Polytechnic University|
|Abstract: ||High-precision, two dimensional planar motion is often required in the manufacturing industry. An ideal planar motor should have a simple and low-cost structure with fast response. Various types of planar motors have been designed, but none of them can fulfill the requirements such as low cost, stiff structure and working under a variety of environments. Switched Reluctance (SR) motor has a simple and robust structure, therefore it has been widely applied in many industrial applications. However, due to its highly nonlinear characteristics, it has not been used in direct-drive, planar motion applications.
The aim of this project is to investigate the feasibility of employing SR technology in two dimensional, high-precision, position control applications. Under this goal, a prototype of SR planar motor has been built. Although some motor parameters are still required to be optimized, the initial machine is capable of achieving high-precision position and trajectory control under selected control algorithms.
For the initial research stage, a thorough performance prediction and analysis have been made with finite element analysis. Simulation results show that the motor has good magnetic characteristics and there is zero mutual coupling between any of the adjacent phase windings, therefore each winding can be controlled independently.
In order to fully understand the behavior of the planar motor prototype, detailed characterization experiments have been carried out. Flux-linkage measurement based on the Step Voltage method and the Alternate Current (AC) excitation method are both performed and their results are compared. Force profiles are measured by direct measurement with a load cell and its result is compared with the results from finite element method. Other magnetic characteristics including hysteresis, leakage flux-linkage and mutual coupling are also measured and verified.
After reviewing various modeling techniques commonly used for SR motors, the nonlinear characteristics of the planar motor, flux-linkage vs. different current levels and positions are modeled with an exponential description function. The modeling precision is verified with its absolute error profile.
Two different control algorithms have been applied to tackle the nonlinearity of the SR planar motor. The first position control algorithm is composed of a reduced size nonlinear force-current-position look-up table compensator with PID control strategy. The main benefit of this method is simple and straightforward implementation, and it is more suitable for industrial applications. The second control scheme is aimed at velocity regulation based on Auto-Disturbance Rejection Control (ADRC). Experiment results show that the proposed position controller is capable of achieving good precision, and the velocity controller is highly robust, and it offers better performance than a traditional PID speed regulator.|
|Degree: ||Ph.D., Dept. of Electrical Engineering, The Hong Kong Polytechnic University, 2007.|
|Description: ||xviii, 168 leaves : ill. ; 31 cm.|
PolyU Library Call No.: [THS] LG51 .H577P EE 2007 Pan
|Rights: ||All rights reserved.|
|Appears in Collections:||EE Theses|
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