Comparison of a Resistance Ratio and Voltage Ratio of the KRISS 1-kV Resistive Voltage Divider Traceable to Quantum-Based National Standards

2021 ◽  
Author(s):  
Sang Hwa Lee ◽  
Kwang Min Yu ◽  
Jeon Hong Kang ◽  
Hyung-Kew Lee ◽  
Sungjung Joo
Keyword(s):  
Voltage Divider ◽  
Resistance Ratio ◽  
National Standards ◽  
Voltage Ratio

Traceability of DC and AC high voltage measurements using voltage divider calibration

2018 ◽  
Vol 55 (2) ◽  
pp. 109-119 ◽  
Author(s):  
Hala M Abdel Mageed ◽  
Faisal Q Alenezi
Keyword(s):  
High Voltage ◽  
International System ◽  
Voltage Divider ◽  
Calibration Method ◽  
Industrial Applications ◽  
Theory And Practice ◽  
National Standards ◽  
Dc Voltage ◽  
Acceptable Accuracy ◽  
System Of Units

This paper focuses on achieving traceability of high voltage measurements up to 200 kV at the Egyptian National Institute of Standards. The measurement system consists of an AC/DC voltmeter and a universal resistive/capacitive high voltage divider. The voltmeter shows measured voltage values based on the scale factor of the voltage divider. The divider ensures a stable capacitance for AC voltage measurements and an additional resistive parallel path for DC voltage measurements. Both the divider and the voltmeter are calibrated in AC and DC modes. All uncertainty components are taken into account to obtain measured values with an acceptable accuracy. The calibration results in traceability to the national standards, which make measurements using the international system of units. The proposed calibration method is useful for the theory and practice of high voltage measurements in education, industrial applications, and electrical metrology studies.

scholarly journals Application of Perovskite Layer to Rotor for Enhanced Stator-Rotor Capacitance for PMSM Shaft Voltage Reduction

Energies ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5762
Author(s):  
Muhammad Aqil ◽  
Jun-Hyuk Im ◽  
Jin Hur
Keyword(s):  
Pulse Width Modulation ◽  
Permanent Magnet Synchronous Motor ◽  
Voltage Divider ◽  
Electric Discharge Machining ◽  
Perovskite Layer ◽  
Voltage Ratio ◽  
Common Mode Voltage ◽  
Three Phase ◽  
Switching Action ◽  
Bus Voltage

Adjustable speed drives use Pulse Width Modulation (PWM) to switch DC-bus voltage for the synthesis of three-phase voltages to provide power to the permanent magnet synchronous motor (PMSM). This switching action produces very short rise and fall times and Common Mode Voltage (CMV) in the motor winding, exciting the parasitic capacitances inherent to the motor geometry. These parasitic capacitances give rise to shaft voltage due to a voltage divider action. Therefore, in this paper, first, motor parasitic capacitances and voltage divider action is explained. Second, the Barium Titanate (BTO) layer is coated onto the rotor to enhance stator-to-rotor compound capacitance and a simulation is performed showing the dependence of the shaft voltage on the permittivity of the perovskite (BTO) layer. The rotor BTO layer reduces the bearing voltage ratio as well. Third, experimental results are presented showing effectiveness of the application of the BTO layer to rotor and reduction of shaft voltage of the motor in anticipation to mitigate the damaging electric discharge machining (EDM) bearing currents. Likewise, the experiment shows that the magnetic design of the motor is not affected by the BTO layer to rotor.

100 KV Scanning Microscope

1972 ◽  
Vol 30 ◽  
pp. 472-473 ◽  
Author(s):  
A. V. Crewe ◽  
M. W. Retsky
Keyword(s):  
High Voltage ◽  
Voltage Divider ◽  
Electron Gun ◽  
Objective Lens ◽  
Parallel Beam ◽  
Emission Point ◽  
Error Amplifier ◽  
External Reference ◽  
Scanning Transmission ◽  
Transmission Microscope

A 100 kv scanning transmission microscope has been built. Briefly, the design is as follows: The electron gun consists of a field emission point and a 3 cm Butler gun. The beam has a crossover outside the gun and is collimated by a condenser lens.The parallel beam passes through a defining aperture and is focused by the objective lens onto the specimen. The elastic electrons are detected by two annular detectors, each subtending a different angle, and the unscattered and inelastic electrons are collected by a third detector. The spectrometer that will separate the inelastic and unscattered electrons has not yet been built.The lens current supplies are stable to within one part per million per hour and have been described elsewhere.The high voltage is also stable to 1 ppm/hr. It consists of the raw supply from a 100 kv Spellman power supply controlled by an external reference voltage, high voltage divider, and error amplifier.

Medicare Advisers Call for National Standards on Imaging

Ob Gyn News ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 43
Author(s):  
JENNIFER SILVERMAN
Keyword(s):  
National Standards
Sign in / Sign up

Export Citation Format

Share Document