 |
 |
EPE Journal Volume 10-1 - Papers
EPE Journal Volume 10-1 - Editorial
By B. Sneyers
The Editorial of the EPE Journal Volume 10 N°1, "EPE Courses: More to come", written by Ir. Brigitte Sneyers, the Secretary General of EPE Association.
EPE Journal Volume 10-1 - Papers
By L. Lorenz
CoolMOS technology - developed for the production of charge-compensated devices - is presented. Due to its novel internal structure, the device offers a dramatic reduction in on-state resistance with a completely altered voltage dependance of the device capacitances. Ruggedness aspects such as avalanche and short-circuit behavior are excellent and reach the limits of active zener-clamped devices. The above-mentioned electrical characteristics make the device suitable for a broad range of applications. The paper also discusses device physics-based selection criteria for fast IGBTs and CoolMOS.
The paper describes innovative SPICE and SABER simulation models incorporating a dynamic connection between electrical and thermal component description. On one hand this enables the realistic simulation of operating states in which a relevant self-heating effect occurs. On the other, the models provide defined thermal nodes which create a connection to the thermal environment of the component and thus, for example, facilitate the investigation and optimization of heatsink options.
By Vinay M. Mistry; S. P. Waikar; K. Gopakumar; L. Umanand; V.T. Ranganathan
In conventional three phase current hysteresis controllers, the current error along the three phase axes are independantly controlled. This will result in random selection of switching vectors causing high inverter switching losses. In this paper, a space vector based multi-axis current hysteresis controller is proposed, in which the current errors along the axes jA, jB, jC (which are othogonal to the A, B, C phase axes respectively) are monitored. The current error boundary in the space phasor domain is a hexagon. The proposed control scheme can be implemented using simple look up tables. The inverter switching states from the look up table are selected based on only current errors (delta currents), along the orthogonal axes to the A B C axes, respectively. When compared to other multi-level current hysteresis current controllers, the advantage of the present scheme is that, only the adjacent inverter voltage vectors close to the motor back emf space phasor voltage, is only used for the inverter switching, for the entire speed range. In the present scheme, the selection of the inverter voltage vectors for PWM switching is achieved by, without any need for computing the machine back emf vector, for the full speed range of the drive system. The proposed scheme is self adapting, as far as the motor space phasor voltage is concerned, and also maintains the controller simplicity and quick response features of a hysteresis current controller. The scheme is simulated and also experimentally verified.
By Moinuddin; A. S. Siddiqui; A. K. Sharma; J. P. Gupta
A Magnetically Levitated Vehicle System (MAGLEV) is nonlinear, complex and imprecise and therefore, difficult to be expressed in terms of a mathematical model. Non-linear feedback control and strategies using linear small perturbation models do not yield satisfactory results. Such a system is best described by quantitatively and easily handled by human operators. A fuzzy logic approach based on imputs; outputs and control response is proposed to control the Maglev system. The input and output variables are usually crisp numbers with many permitted levels in an allowed range, and the system parameters are linguistic in nature. A multilevel fuzzy logic rule based control strategy is being suggested for the Maglev system. The proposed control strategy offers advantages in designing a fuzzy controller for the Maglev system.
By J. A. Santisteban; A. O. Salazar; R. M. Stephan
An electromagnetic and a mechanical model for a bearingless electric motor are presented. Based on these models, a controller structure is proposed and simulations presented. A laboratory prototype of this motor was constructed and experimental results with load validated the model. The proposed approach can also be used for the design of better controllers.