Application of active magnetic bearing for tubular linear induction motor in onshore oil pumping

• Grant number: 08/01900-7
• Support Opportunities: Regular Research Grants
• Start date: June 01, 2008
• End date: November 30, 2010
• Field of knowledge: Engineering - Electrical Engineering - Industrial Electronics, Electronic Systems and Controls
• Principal Investigator: José Jaime da Cruz
• Grantee: José Jaime da Cruz
• Host Institution: Escola Politécnica (EP). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

MATÆOS, which is the Portuguese acronym for Tubular Asynchronous Motor for Onshore Oil Exploitation, is a tubular linear induction motor that has been developed at EPUSP. It is intended to directly drive the sucker-rod pump installed in the down hole of a subterranean oil well. In continuation to previous research works done at EPUSP involving magnetic levitation systems this project aims the development of an active magnetic bearing (AMB) system for a prototype of a tubular linear induction motor in substitution to the existent traditional mechanical bearing. The complete development and control of the AMB will be the objective of this work. This kind of the system is inherently unstable and highly nonlinear, being an excellent case for the study and comparison of different control methodologies. The project includes the construction of prototype of the magnetic bearings with the software necessary to the operation of the system. The levitation control of the bearings will be carried out through a digital realization of the controller with the use of Labview and AD/DA converter modules. Using the system model, the controllers will be tuned to accomplish with the requirements of stability and disturbance rejection that tend to deviate the air gap from its nominal value. The comparison between control techniques in closed-loop will be done by using the experimental results. Both the project and contract to construct the first AMB were already finished. The project was carried out by using the finite element method both to analyze the flux density and to establish the relationship between the radial force and the winding current. To conclude the levitation system it will be necessary to purchase a second bearing, a position sensor and a digital controller hardware with both analog and digital input and output.It is expected that this project will serve as the basis for the development of the doctorate thesis of Eduardo Alves da Costa as well as the publication of related papers. The development of magnetic bearing levitation know-how in such an important practical application of tubular linear inductions motors is the main goal of the proposed project. (AU)