| 1. |
- Elg, Alf Peter, et al.
(författare)
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Characterization of dielectric properties of insulating materials for use in an HVDC reference divider
- 2012
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Ingår i: CPEM Digest (Conference on Precision Electromagnetic Measurements). - 9781467304399 ; , s. 80-81
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Konferensbidrag (refereegranskat)abstract
- Dielectric properties of polyethylene (PE), polyoxymethylene (POM) and ceramic glass (MACOR) are compared. Their suitability to act as a support for a resistor chain in a wideband HVDC reference divider is characterized. The support material forms a parallel capacitance to the resistive resistor chain, and a bandwidth of more than 100 kHz is needed. The frequency dependence of dielectric constant has been measured in the range 20 - 100 kHz. The depolarization current of these materials was measured to be at least 6 orders of magnitude lower than the current through the resistive chain. Neither MACOR nor PE does build up space charge which POM does. Possessing the highest dielectric constant makes MACOR well suited for the application.
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| 2. |
- Houtzager, Ernest, et al.
(författare)
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Selection and characterization of resistors for a HVDC reference divider
- 2012
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Ingår i: Conference on Precision Electromagnetic Measurements, CPEM 2012. ; , s. 197-198
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Konferensbidrag (refereegranskat)abstract
- This paper describes the selection and characterization of resistors for a 1000 kV HVDC divider. One thousand 10 MΩ resistors will be connected in series in the final design. Due to the large number of resistors only a randomly selected set has been characterized. The measured temperature and voltage coefficients of the resistors are around 1 μΩ/Ω/K and -10 μΩ/Ω/kV respectively, which make them very suitable for reaching the overall desired divider uncertainty of better than 100 μV/V.
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| 3. |
- Hällström, Jari K., et al.
(författare)
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Bilateral three-phase 50 Hz power comparison
- 2012
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Ingår i: Conference on Precision Electromagnetic Measurements, CPEM 2012. ; , s. 118-119
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Konferensbidrag (refereegranskat)abstract
- This paper describes the results of a bilateral three-phase power comparison between SP, Sweden and MIKES, Finland. A three-phase precision electricity meter was used a transfer reference. Both active and reactive three-phase power measurements were compared.
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| 4. |
- Hällström, Jari K., et al.
(författare)
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Performance of a wideband 200-kV HVDC reference divider module
- 2014
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Ingår i: IEEE Transactions on Instrumentation and Measurement. - 0018-9456 .- 1557-9662. ; 63:9, s. 2264-2270
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Tidskriftsartikel (refereegranskat)abstract
- This paper describes the design and performance of a wideband high-voltage dc (HVDC) reference divider module. The module has a nominal voltage of 200 kV, and it has been designed so that a number of modules can be stacked to extend voltages up to 1000 kV. The module, or a stack of modules, will be used for traceable calibration of HVDC measuring systems in customers' laboratories. The first priority in the design was the accuracy of HVDC measurements. In addition, the divider was designed to have wide bandwidth, both to enable measurement of ripple voltages and to prevent damage during possible flashovers.
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| 5. |
- Nilsson, Andreas, et al.
(författare)
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An improved method for switching-impulse evaluation
- 2012
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Ingår i: Conference on Precision Electromagnetic Measurements, CPEM 2012. - : IEEE. ; , s. 20-21
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Konferensbidrag (refereegranskat)abstract
- The standard IEC 60060-1:2010 "High-Voltage Test Techniques - Part 1: General definitions and test requirements" defines a parameter called "time to peak". In addition it describes a method for evaluating the time to peak of switching-impulses. This method suffers from two problems. Firstly, the method is only to be applied to so-called standard switching-impulses. That is impulses essentially equivalent to two super-imposed exponential curves. Secondly, the results given by the method only agree with the definition for standard switching-impulses that have certain combinations of rise times and fall times. This paper proposes an alternative, more general and robust method for determining the time to peak.
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