Loading...
| Friend's email | |
| Your name | |
| Your email | |
| enter code | |
This page was sent successfuly
- Type of Document: Ph.D. Dissertation
- Language: Farsi
- Document No: 45520 (05)
- University: Sharif University of Technology
- Department: Electrical Engineering
- Advisor(s): Zolghadri, Mohammad Reza; Fardmanesh, Mehdi
- Abstract:
- Using superconducting synchronous machine leads to many advantages such as increasing overall efficiency, decreasing mass and valume of peropulsion system, eliminating some restrictions in hydrodynamic design , etc. The goal of this thesis is design of 200 kW, with 250 rpm superconducting synchronous motor for small ship propulsion drive application. The low speed motor can be directly coupled to the propeller whitch eliminates bulky and inefficient gearbox. After comparison of different structures of superconducting synchronous machines, finally rotating superconducting field with stationary copper armature winding is selected as the most approporiate structure for our application.
For conventional machines, magnetic circuit theory is capable of being used to calculate the machine magnetic parameters with good precision. But for a large air-gap machine, the magnetic circuit is not well definable. Consequently, the magnetic calculation of machine is quite different and makes the design of the superconducting synchronous machines more challenging. Calculation of magnetic flux density distribution in the machine is the fundamental step in electromagnetic design of machine. In this thesis a new model of superconducting machine is suggested and the basic formulas for a radial large air-gap machine, which is more general in comparison to the earlier works, is derived. This analytical modeling can be used to compare different structures of the machine with respect to the machine parameters such as weight, volume, length of HTS tape, perpendicular component of the magnetic field on the HTS tape, etc. Moreover, the self and mutual impedances of the machine are calculated based on the suggested model which improves the accuracy of the analytical calculations in comparision with other methods.
In design process, a MATLAB code is utilized. Also, the machine is optimized by genetic algorithm. Considering high cost of superconducting tapes, the fitness function of genetic alghoritm is defined as sum of the weighted machine mass and required length of the superconducting tapes.
In order to minimize the power of the cooling system, superconducting field coils are placed in a vacuum chamber. In addition an electromagnetic shield should be used to minimize the transient magnetic field which causes significant losses in superconducting coils. In this thesis a single aluminium chamber is used for both purposes. An alghorithm is suggested to calculate the temperatue of the superconducting coils. Using the proposed alghorithm, the approporiate cooling system parameters such as cooling ducts, cooling gas type, and flow are found.
- Keywords:
- Genetic Algorithm ; Superconducting Synchronous Motor ; Electrical Machines ; Electric Machines Electromagnetic Analysis ; Electrical Machine Design
Digital Object List-
محتواي کتاب - view
Bookmark