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EPE Journal Volume 02-3 - Papers
- A Brief Status Review of Switched Reluctance Drives
- Advanced Drive Systems and Infrastructure for Electric or Hybrid Buses, Vans and Passenger Cars (II)
- Interaction between a series-resonant converter and a transformer
- Design and Analysis of Buck Quasi-Resonant Converter Using IGBT's
- Determination of thermal constraints on semiconductors in power circuits
- Simplified digital control for three phase induction motor drive
EPE Journal Volume 02-3 - Editorial
By W. Wymeersch
The Editorial of the EPE Journal Volume 2 N°3, "Power electronics and its industrial applications", written by Mr. Werner Wymeersch, Member of EPE Association's International Steering Committee.
EPE Journal Volume 02-3 - Papers
By P. Lawrenson
Switched reluctance (SR) drives are relatively new forms of brushless drive which eliminate the need for any rotor conductors or permanent magnets. They operate on forces of magnetic attraction and consequently need only unidirectional stator-winding currents which results in a particularly economical and robust electronic controller.
Despite this simplicity and robustness, SR drives can more than match the attractiveness of fully-controlled dc systems; and in terms of specific torque and power densities, efficiency, permissible speeds, dynamic response and thermal behaviour, their performance levels generally exceed those of induction, dc and universal motors.
Fig. 6 is illustrative of this for a general purpose industrial drive in terms of efficiency, torque and power output, low-speed performance and constant power range. The paper discribes similar qualities in applications and sizes for household appliances, traction, compressors and more generally; and it outlines why manufacturing costs are very competitive.
Initially, the novelty of SR drives, and their contradiction of received wisdom about the fundamental capacities of electrical machinesgenerally, slowed their acceptance in both industrial and academic spheres. That position is now completely changed, and large scale developments are in hand worldwide for many new products.
By G. Maggetto
In part I of this paper, attention has been firstly paid to general aspects of the introduction of electric and hybrid vehicles to reduce the air pollution. It has been shown that the emissions by electric vehicle are significantly lower than for petrol and diesel vehicles, except for sulphor dioxide, but the last one is due to reduce significantly in the future. A discussion of the daily mileage led to the conclusion that the present-day car fleet is conceived for trips (more than 100 km) that only represent less than 10% of the total number of trips or at the most 30% (i.e. all those trips longer than 10 km) of the total number of trips. It must be particularly stressed that electric and hybrid vehicle technology is clearly still in the infancy of its development. The basic structure of the electric vehicle is quite simple. A tentative description of the emission characteristics of city cars, passenger cars, vans, minibuses and buses has been performed together with upper level of useful characteristics. The characterisitcs of future type of batteries and of presently available batteries have been given to alow a comparison with the 500 W/kg power density of a widespread typical internal combustion engine. In this part II, after a short description of the hybrid solutions, we will devote some space to the presentation of the State of the Art of the electric components of EV's and HV's. This presentation has two main goals:
- to show that the today technology allows without doubt to "assemble" an electric or an hybrid vehicle;
- to try to indicate the long way still to be covered before the grade of optimization of the vehicles with eniternal combustion engine (ICE), after a century of development, can be reached.
The role of the infrastructure and of two important scientific associations (AVERE and CITELEC) will finally be explained in the third part as to their impact on the future development and introduction of EV's and HV's.
Part I of this paper can be found in EPE Journal Volume 1992-2, Part III in EPE Journal Volume 1992-4.
By J. B. Klaassens; H. W. Klesser; M. P. N. van Wesenbeeck; K. van de Wint
The paper demonstrates the existence of various modes of transformer-induced low-frequency oscillations (TLOs) which can be observed in the series-resonant power converter with a transformer integrated in the resonant circuit. The modes of operation under conditions of cyclic stability are explained for TLOs at both the primary side and the secondary side of the transformer. The TLO phenomena cause various problems, e.g. the instability of waveforms and reduction of the power capacity. The paper will also present a practical solution to overcome the indicated problems for series-resonant converters with an integrated transformer. The results of simulation and experimental observation confirm the existence of the TLOs.
By B. Baha
In this paper, the design and analysis of a Buck quasi-resonant converter (QRC) has been presented using Zero Current Switches (ZCS). The maximum voltage and current stresses of different components have been derived using the state plane of this converter. The results of the analysis are verified by experiment and PSpice simulations. In addition, the Insulated Gate-Bipolar transistors (IGBT) have been found to be as a suitable switching device for this particular converter up to 100 kHz switching frequency.
By J. P. Laur; J. Jalade; J. M. Dorkel
The author's aim is to present a complete method of evaluation of the operating temperature of power devices involving electrical and thermal behaviour simulation. Comparison of simulated and experimental results shows that a reasonable agreement can be obtained but the accuracy of power component models must still be improved before writing a complete main software for electro-thermal behaviour simulation.
By B. Maurice
The generation of well balanced three phase sine waves to control induction motor normally requires complex control circuitry. The introduction of variable speed induction motor into large volume appliances (100 W - 1 kW) requires the design of cost effective solutions. The simplified solution proposed in this paper uses a standard microcontroller including an internal Direct Memory Access (DMA). This solution spares the use of dedicated IC (hardware being replaced by software), and saves over 50% of CPU time to perform any control and supervision tasks. A practical solution to quantize three phase sinewaves, and to create the corresponding DMA table is presented. Motor voltage and motor frequency can be chosen independently. A dead time avoiding cross conduction through the bridge is also created by software. Each of the six digital outputs sets directly the state of the six power MOSFETs (or IGBTs) of the bridge via insulated interface. This interface is described in the second part of the paper. A new fully isolated pulse controlled gate driver is used. No floating auxiliary supply is needed and safety standards are met. Large dV/dt immunity is achieved. Results of practical examples are given.