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EPE 2009 - Subtopic 10-2 - LS: 'Electical Machines - Losses'
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2009 - Conference > EPE 2009 - Topic 10: 'Electrical Machines' > EPE 2009 - Subtopic 10-2 - LS: 'Electical Machines - Losses'
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	Computation of Iron Losses in Electrical Machines by Multi-Domain Simulations   By GAIZKA UGALDE, GAIZKA ALMANDOZ, JAVIER POZA, ANTONIO GONZALEZ	[View]   [Download]
Abstract: Nowadays the majority of electric drives work at variable speeds. In this kind of drives the electrical machines are supplied by inverters which generate modulated voltages. It is widely known that these non sinusoidal voltages cause additional current harmonics dealing to higher iron losses than with sinusoidal voltages. The iron losses affect to several design constraints as the efficiency and the thermal behavior of electrical machine. Hence, the accurate computation of the iron losses under different supply voltage conditions is very important in order to optimize the machine design as much as possible. This work deals with multi-domain simulations in order to calculate the iron losses in permanent magnet synchronous machines (PMSM) under Pulse Width Modulated (PWM) voltages. The current supplies are implemented in the simulation system MATLAB-SIMULINK. Whereas the electrical machine is simulated using the Finite Element Method (FEM). The iron losses are computed by a post-processing analysis carried out using the tool so called Loss Surface Model (LSM) which is integrated in the FEM software FLUX of Cedrat. Finally, experimental tests are performed in order to validate the proposed methodology.
	Modeling the induction machine’s main inductance as a function of the supply frequency and the magnetizing and the torque building component of the stator cur   By Roland SEEBACHER, Guenther DANNERER, Klaus KRISCHAN, Reinhard INGRUBER	[View]   [Download]
Abstract: According to earlier work and papers by other authors, the main flux path of an induction machine is not only saturated due to the magnetizing current, or in other words “the magnetizing inductance can be modeled as a function of torque”. In addition, at a given magnetizing current, the flux linkage decreases with rising supply frequency. These effects should be considered when using control algorithms based on the main inductance, as for example rotor flux oriented control. In the paper at hand a method is proposed to extend the induction machine’s standard fundamental wave model taking regard of the changes of the main inductance in dependence of the magnetizing and the torque building component of the stator current. In addition a method to estimate the required parameters is proposed. Validation is carried out via additional measurements and FEM calculations.
	New method for temperature rise test of high power moto-ventilated induction motors   By Abdollah MIRZAIAN	[View]   [Download]
Abstract: The motor manufacturers have generally the necessary equipment for the temperature rise test, at the rated conditions, of the motors below 6 MW. Today, high power induction motors up to 25 MW, supplied by PWM converters are installed, specially in marine propulsion applications. As the motor manufacturers’ factory electric network is not designed to provide such high powers, many indirect test methods have been proposed and a few of them are included in IEC 60034-29 ed. 1 standard [29]. These methods need : ·additional rotating machines, not always available or ·bi-directional static converters, causing high pulsating, and bi-directional power exchange with the factory network. The paper proposes a new method, using only the motor & converter under test without any additional machine. The factory network will provide a low and constant electrical power. No power is regenerated back, to the supply network. The new temperature rise test method, called “Static Torque Test” is now fully approved by all the major classification societies (DNV – LRS – BV – ABS – RINA).