Showing papers by "Michele Pastorelli published in 2011"

Experimental methods for synchronous machines evaluation by an accurate magnetic model identification

Abstract: The magnetic model of synchronous machines is the relationship between the machine flux and machine current. knowing the machine magnetic model is fundamental for machine design evaluation and for optimal machine control. This paper presents an experimental approach for the magnetic model identification of any synchronous electrical machine. The presented procedure requires an inverter with current control, while the machine under test must be equipped with a position sensor. The proposed approach has been used with three different hardware platforms applied to four different synchronous machines.

Design of a gyroscopic wave energy system

Abstract: The extraction of energy from ocean waves has been investigated in Europe since the 1970s. During the research process several devices have been proposed and a few of them have been built full scale and deployed to the ocean. Unlike other renewable energies, so far there has not been a device standing out to be the most suitable to exploit wave power. One of the practical problems to be solved in a Wave Energy Converter (WEC) is durability in the harsh marine environment. This could be critical if parts of the converter such as turbine rotors or auxiliary floats are needed to move or to react while exposed to seawater and spray. One method to solve the problem is to use a WEC composed just by one sealed floating body carrying a gyroscope. The inertial effects of the gyroscope are activated by the float motion and are used to drive a generator. The whole system operates in the clean environment inside the float. In this work a procedure to design the ISWEC device (Inertial Sea Wave Energy Converter) is outlined. The mechanical equations describing the system are linearized, studied in the frequency domain and used as a mathematical tool in the design process. The method is then applied iteratively to design a scaled prototype model to be tested in the wave tank at the University of Naples. The final version of the prototype model is then scaled up to evaluate the performances of a full scale device.

High speed sensorless control for induction machines in vacuum pump application

Abstract: A sensorless rotor field oriented control of an induction motor drive for high speed vacuum pumps is presented in this paper. Motion sensorless control is mandatory for this application, due to space constraints, hostile environment, cost reasons and reliability. The adoption of field oriented control instead of the conventional V/Hz control is justified by the application peculiarities. The complete system is described including the motor, the converter and the control features. Experimental results are provided for a drive in production.