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The new GNP250 power supply by Sames Technologies
Tested and approved by EDF (Electricité de France)
Article from "Precip Newsletter" by Juanita Brand. © The McIlvaine Company
Everybody now accepts that a major step was taken in the evolution of the performances of dusting systems, after the breakthrough of new technologies in High Voltage power supplies.
With a far better performance rating than the high frequency power supplies recently offered to the market place, this new generation of power supplies has been approved by EDF, and production tested for several years in their thermal power plant at Le Havre, in Normandy, France.
This power supply was designed and developped by Sames Technologies, France, based on their 60 years of experience handling HV.
This technology is based on the Greinacher principle, which permits to work under high frequencies, and mostly, to produce a non resounding electronic system, as opposed to what was offered to the market place until this innovation.
Such a power supply can be 28 kVA, 56 kVA, or 80 kVA, all depending on the numbers of GNP's that are installed in parallel.
The first aplication of this principle, is the considerable reduction in volume and weight of the proposed equipment, as opposed to that of the classical transformer/rectifior, but also as opposed to the other more conventional single or double resounding high frequency systems.
Better than a long speech, the picture speaks for itself. |
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The other consequence of Sames technological Know-how, is to have created an "intelligent" unit. By and large, this sytem does not require a control panel crammed with plc's, driven by a master PC. These are really integral with each unit. A direct result of that, is the high cost reduction ,at least 50%, that the end user may expect to get out of his investment.
The supply, the construction and start up of these expensive materials being if not totally eradicated, at least extremely simplified.
Indirectly, its installation does not command the mandatory usage of dusting experts, plc experts, or computer experts; that's the beauty of its conception. Sames designed a self-adapting system, which provides a maximum voltage and current, regardless of the coal, for instance, and which handles automatically many more parameters. Simplifying the connection from the HV supply down to the emmitting electrodes of the duster, is in itself another breakthrough.
This was made possible by the development of a new HV cable, whose implementation does not require special and binding precautions. Its installation is most simple, and is safe all around for the people who handle it, and the systems who use it. We are talking here of a flexible cable, 13 mm diameter, crush resistant, rated for 120 kV, and resistant to temperatures up to 180 C° (360 F).
(See picture below.) |
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All these featured performances of the GNP 250 add to those of the unit itself.
If only one thing is to be remembered, let's keep in mind the data sheets of the high frequency supplies, that are known, described countless times, such as the power factor = 90% (GNP > 95%),
an undulation rating 3-5% (GNP < 1%, as shown in the chart below) |
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The operation in parallel of at least 2 GNP's offers more flexibility, more safety for the operator:
• The GNP's fiber optic communication mode with the supervisor, without interfacing automatism,
• The concept of 2 disconnectable assemblies ( the power supply and the HV unit) as shown in the picture,
Are extra advantages that come with the GNP. |
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In many cases, the power installed will require a bigger power supply, capable of 80-90 kV, and current output in the order of 800 to 1000 mA.
Sames is currently working on a GNP 800, to meet these requirements. |
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