Electric power conversion systems – Current conversion – Including d.c.-a.c.-d.c. converter
Patent
1998-05-07
1999-05-11
Hecker, Stuart N.
Electric power conversion systems
Current conversion
Including d.c.-a.c.-d.c. converter
363 21, H02M3/335
Patent
active
059034467
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to the conversion of electrical energy and more particularly the creation, from a continuous input voltage, of several continuous output voltages and deals generally with assuring the most perfect possible regulation of the outlet voltage or voltages relative, on the one hand, to variations of input voltage, and, on the other hand, variations of the output current or currents absorbs by the load or loads, and this with the highest efficiency possible.
Various techniques have been used until now, so as to ensure such a regulation.
The first types of voltage converters were with a linear regulator thermally dissipating the excess energy between the requirements of the load and the supply capacities. Such converters are bulky and of low efficiency, of the order of 50%.
Then there appeared chopper converters with forced switching in which the transfer of energy just necessary, from the input to the output or outputs, takes place by energy quanta drawn in a period manner from the source, stored in reactive components, then restituted toward the load or loads by so-called chopping techniques using switching with electronic switches.
The principal drawback of these converters arises from the fact that each switching is accompanied by losses which increase with the number of switchings, which is to say the frequency of chopping.
However, with the development of the characteristics of the components, it has been able to reach an optimum with the type of converter with apparatuses functioning at chopping frequencies of the order of 200 KHz with an efficiency that can reach 80%.
These converters have been recently supplanted by devices using resonance chopping techniques whose principle is to use, even to amplify, the effects of the parasitic elements by addition of passive components forming resonant circuits. These structures thus permit creating conditions under which the voltages at the terminals of the switches or switching diodes, or the current which passes through them, are zero at the moments at which their switching is ordered. The switching losses are corresponding reduced.
This is permitted raising the chopping frequency, which exceeded 500 KHz, whilst correspondingly reducing the weight and volume of the converter.
Such techniques nevertheless remain difficult to use and have drawbacks and limits.
Upon each switching there arise strong currents or over-voltages in the resonance circuits and hence losses by conduction. If the switching losses are reduced, the conduction losses conversely are increased.
Moreover, this drawback has required over-dimensioning the chopping components relative to conventional supply, by a factor of 1.5 to 2.
Still more recently there have appeared new conversion techniques with a chopping regulator with soft switching. They are distinguished from the resonance techniques by the absence of a resonant circuit which is costly as to loss by conduction and by switching conditions at zero voltage, hence with less loss per switching, obtained from elements of conventional chopping techniques.
These new techniques are for example disclosed in U.S. Pat. Nos. 4,441,146, 5,057,986, and 5,126,931, as well as in the publications: Flyback Converters" of R. Watson, F. C. Lee, G. C. Hua; PESC Conference, 1994; Correction Applications" of R. Watson, F. C. Lee, G. C. Hua; PESC Conference, 1994.
However, the effectiveness of these techniques remains limited as to the range of variation of the input voltage, which is insufficient in most industrial applications. Thus, for large variations of this input voltage the conditions for soft switching are no longer present and to restore these conditions one must have recourse to arrangements, particularly resonant circuits, which give rise to serious problems of loss by conduction.
The present invention particularly provides, so as to adapt these soft switching techniques to a wider range of input voltages, to restore said soft switching conditions but by simpler means reducing the conduction losses, as well as the cost and
REFERENCES:
patent: 4720668 (1988-01-01), Lee et al.
patent: 4823249 (1989-04-01), Garcia, II
patent: 5177675 (1993-01-01), Archer
patent: 5262930 (1993-11-01), Hua et al.
patent: 5434767 (1995-07-01), Bararseh et al.
patent: 5729444 (1998-03-01), Perol
Huillet Henri
Ploquin Didier
Gaia Converter
Hecker Stuart N.
LandOfFree
Direct current voltage converter with soft switching does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Direct current voltage converter with soft switching, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Direct current voltage converter with soft switching will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-250094