Resistive Voltage Divider Research Articles

Temperature Rise Characteristics and Error Analysis of a DC Voltage Divider

Measurement accuracy is an important performance indicator for high-voltage direct current (HVDC) voltage dividers. The temperature rise effect for a HVDC voltage divider’s internal resistance has an adverse effect on measurement accuracy. In this paper, by building a solid model of a DC voltage divider, the internal temperature rise characteristic and error caused by the temperature rise in a resistance voltage divider were theoretically simulated. We found that with the increase in height and working time, the internal temperature of the voltage divider increased. The results also showed that the lowest temperature was near the lower flange and the highest temperature was near the upper flange in the middle of the voltage divider. The error caused by the temperature rise increased first and then decreased gradually with divider height, increasing with its working time. The measurement error caused by the internal temperature difference in steady state reached a maximum of 158.4 ppm. This study provides a theoretical basis to determine the structure and accuracy improvement for a resistive voltage divider, which is helpful for the selection of components and the optimization of the heat dissipation structure.

Digital Compensation of a Resistive Voltage Divider for Power Measurement

The paper presents a method for digital compensation of the ratio and phase angle errors of a resistive voltage divider. The system consists of a separate electrical circuit of a resistive divider, and a digital compensation system based on National Instruments (NI) PCI eXtension for Instrumentation (PXI) PXI-5922 digital acquisition cards (DAQ). A novel approach to the real-time compensation is presented, using digital signal processing. The algorithm is based on Wiener filtering and finite-impulse-response (FIR) filters. The proposed digital compensation, using FIR digital filtration and NI PXI DAQs, gives maximum magnitude error below 400 ppm and the phase angle error below 4500 μrad, in the frequency band 50 Hz–100 kHz. The algorithm allows the fine-tuning of the compensation to adjust to the possible change in the original transfer function due to the aging of the components.

Advance in the development of wideband resistive voltage dividers

The advance in the development of a set of resistive dividers is described. The frequency range is 50 Hz to 100 kHz and the voltage, from 4 V to 1024 V. It was used a special design for reducing the stray capacitances and to limit the temperature, especially for the highest voltages. Tests on frequency response, ratio and phase, are shown in this paper.

Modeling of a Resistive Voltage Divider by Rational Functions: Uncertainty Evaluation

This article describes the modeling of a resistive voltage divider (RVD) by rational functions using the vector fitting (VF) tool. The method is applied to ratio and phase displacement measurements over a wide frequency range. A Monte Carlo simulation-based sensitivity analysis was carried out to properly estimate the model uncertainty. The modeling tool proved to be an advantageous alternative with suitable adherence to the traced points, not exceeding a few parts in 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sup> . Real and imaginary parts can be taken into account in the same fitting, preserving their correlation for the uncertainty estimation. Such a black-box approach can also help to estimate intermediate and above limit points since the transfer function is given by the tool.

CMOS Schmitt – Inverter-Based Internal Reference Comparator Array for High Temperature Flash ADC

ABSTRACT Localized data conversions for sensors placed under harsh environmental conditions often require Analog to Digital Converters (ADC) capable of working under wide operating temperature range. Even though the fastest analog to digital converter, flash ADC is omitted from the high temperature regime due to the requirements of reference voltage source, reference voltage divider and a comparator array capable of providing stable operation under wide operating temperatures. A CMOS Schmitt inverter-based internal reference comparator array for flash ADC which is efficient in terms of area and power consumption, capable of working under wide temperature range is presented in this paper. The proposed idea replaces the reference voltage source, resistive reference voltage divider and differential comparator array of a conventional flash ADC by an array of suitably sized Schmitt inverters. The circuit was simulated for static and dynamic characteristics with gpdk 180 nm library using cadence virtuoso simulation suite. The voltage transfer characteristic curve (VTC) of the proposed comparator array was found invariable when a temperature sweep in the range of −40 to 170 degree Celsius was performed. Each of the comparator in the proposed array consumes a silicon area of 40.68 and the average dynamic power consumption per cycle is estimated as 103.1 uW.

Supplementary comparison EURAMET.EM-S42, comparison of lightning impulse (LI) reference measuring systems

Main textIn 2016 the Consultative Committee for Electricity and Magnetism (CCEM) commissioned a supplementary comparison EURAMET.EM-S42 of Lightning Impulse (LI) measurement systems. This comparison was piloted by RISE (Sweden, formerly SP), and it was supported by VTT MIKES (Finland) and FFII LCOE (Spain). Eleven National Metrology Institutes (NMI) and two Designated Institutes (DI) from four Regional Metrology Organizations, EURAMET, COOMET, APMP and SIM, took part in the comparison.A commercial travelling measuring system (TRMS) for Lightning Impulse (LI) measurement was adopted for the comparison. The TRMS consisted of a 700 kV resistive voltage divider and a transient recorder with computer. The TRMS was calibrated by the pilot lab in November 2016 before start of the comparison, and the first circulation was between five EURAMET NMI/DIs. After an intermediate calibration by the pilot lab in July 2017, the TRMS was circulated between seven NMI/DIs in the other regional organisations. On the return of the TRMS in March 2019 a final calibration was made by the pilot lab.The measured parameters are defined in IEC60060-1. Test voltage value (U t), front time (T 1), time to half value (T 2) and relative overshoot (β') were measured for full impulses; and extreme value (U e) and time to chopping (T c) for front chopped waveform. The test voltage value ranged from -700 kV to 700 kV with two full and one chopped impulse waveform. A set of preferred voltage levels and waveforms was defined. The obtained expanded uncertainties (k = 2) of the comparison reference values (CRV) were: <0.3% for U t, <1.3% for T 1, <1.0% for T 2, <0.4% for β', <0.6% for U e and <1.4% for T c.The transfer reference measuring system of the previous LI comparison (EU-SMT4-CT98-2270), arranged between 1999 and 2002, is linked to this comparison. The link is established by comparing VTT MIKES system used 20 years ago with that used in this comparison.To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Device for Measurements of Ultraviolet’s Power Radiation

The paper presents a technique for developing a device for measurements of power of ultraviolet (UV) radiation. The paper provides a brief analysis of existing approaches in the design of UV dosimeters. The rationale for the design of the dosimeter using an UV photodiode is given. The choice of a photodiode based on cadmium sulfide is made on the basis of the technological equipment existing in Ukraine, the level of development of technological modes that allow, at low technology costs, to obtain photodiodes with parameters not inferior to expensive foreign analogues based on materials of the A3B5 group and silicon carbide. The problems that were solved when developing a photodiode based on CdS and the original solutions found by the authors of the development are shown. The primary transducer is a photodiode based on the surface-barrier structure of p-Cu1.8S/n-CdS with a photosensitive component based on cadmium sulfide CdS. At a wavelength of λ ~ 250 nm, the sensitivity of p-Cu1.8S/n-CdS sensors is two times higher than GaP-based Schottky diodes. The value of the output current depends on the power of the UV radiation and lies within 0.0001-0.2 mA. The advantages of the developed sensor are the simplicity and low cost of the production technology, the ability to produce films of a large area, the characteristics of expensive foreign industrial UV photodiodes. The stages of development of the amplifier circuit for the selected photodiode are given. To design the amplifier circuit, the existing GUVA-S12SD UV Sensor V2 amplifier circuit was analyzed, and a custom circuit was developed with the following advantages: unipolar power; smaller potential difference between input and output compared to analog; different voltages are measured. The developed circuit uses the simplest resistive voltage divider, which is two series resistors connected to a voltage source. The scheme denominations were calculated. The sequence of printed circuit board (PCB) execution in the Sprint-Layout software environment is described. An image of the developed circuit board is shown. An analog-to-digital converter K1108PV1A is selected for signal processing from the amplifier and its technical characteristics are given. The block diagram of the dosimeter of energy illumination is offered: a photodiode, an amplifier of an input signal, an analog-to-digital converter, a microcontroller. As a microprocessor to be connected to the ADC, an electronic stand based on a microcontroller will be used to debug programs using ATmega16A. The obtained circuit solutions for the construction of a UV dosimeter based on a CdS photodiode can be used to quickly create an industrial device that will be an integral part of the complexes for disinfecting the metro and other rooms from viral infections.

Design Method for a Wideband Resistive Voltage Divider Based on Average Impedance Matching With Optimal Solution Methods

This article proposes a design method for wideband resistive voltage dividers (WRVDs), working in the range of power frequencies to a few megahertz, with serial-parallel construction. It introduces an extended concept of the Hamon method into the WRVDs, not in a conventional way like balancing a bridge, but in a new way that involves impedance matching with optimal solution methods. With this method, average resistance matching and stray capacitance matching are simultaneously realized by an optimal arrangement of two element resistor groups as the input and output resistors. The surrounding stray capacitances between the resistors and chassis are also considered. The performance has been confirmed to improve by about 50 times, compared with that without the method.

A Resistive Voltage Divider for Power Measurements

The paper presents a resistive voltage divider (RVD), developed for power measurements at much higher frequencies than the traditional 50 Hz. The design of the RVD and the methods of its evaluation are described. The RVD is intended to be used in a digital sampling wattmeter application based on National Instruments PXI-4461 Dynamic Signal Analyzer. The design of the divider includes individual copper guards for each resistor, driven by the auxiliary chain of resistors. To reduce the leakage currents, the PTFE terminals are applied between pins of the resistors and the printed circuit board.

Inference of X-Ray Emission From a Plasma Focus Discharge: Comparison Between Characteristic Parameters and Neural Network Analyses

Pulsed plasma discharges, such as the plasma focus, are a source of pulsed X rays, therefore it is desirable to understand the relationship between this fast transient phenomena and the electrical variables of the discharge. Parameters from the electrical diagnostic signals are typically used to characterize the plasma focus discharge and for the correlations with X rays measurements via scatter plots. To further evaluate relevant information in the electrical signals, besides the characteristic parameters, an implementation of different types of machine learning algorithms, that included deep learning, was performed. A classification of pulses associated with an X rays measurement, in terms of the electrical signals data as input, was carried out. Two approaches were compared: the selection of the characteristic parameters and the use of the entire signals so the algorithms could find additional information for the classification task. The electrical diagnostic signals corresponded to: the voltage at the electrodes of the discharge chamber measured with a resistive voltage divider; time variation of the circuit current measured with a Rogowski coil and an inductive loop sensor; and the electromagnetic burst from the circuit measured with a Vivaldi antenna. The X rays measurement corresponded to the signal obtained from a scintillator-photomultiplier. In terms of the performance of the algorithms models in this classification problem, the results indicated that there is no significative improvements when using the entire signal or the selection of characteristic parameters. The best results were obtained when the following parameters were used: voltage at time of gas breakdown, voltage at time of pinch, current at time of pinch, time derivative of current at time of pinch, time from breakdown to pinch, and the Fast Fourier Transform of the part of the Vivaldi antenna signal related to the pinch event.

XNOR-SRAM: In-Memory Computing SRAM Macro for Binary/Ternary Deep Neural Networks

We present XNOR-SRAM, a mixed-signal in-memory computing (IMC) SRAM macro that computes ternary-XNOR-and-accumulate (XAC) operations in binary/ternary deep neural networks (DNNs) without row-by-row data access. The XNOR-SRAM bitcell embeds circuits for ternary XNOR operations, which are accumulated on the read bitline (RBL) by simultaneously turning on all 256 rows, essentially forming a resistive voltage divider. The analog RBL voltage is digitized with a column-multiplexed 11-level flash analog-to-digital converter (ADC) at the XNOR-SRAM periphery. XNOR-SRAM is prototyped in a 65-nm CMOS and achieves the energy efficiency of 403 TOPS/W for ternary-XAC operations with 88.8% test accuracy for the CIFAR-10 data set at 0.6-V supply. This marks $33\times $ better energy efficiency and $300\times $ better energy–delay product than conventional digital hardware and also represents among the best tradeoff in energy efficiency and DNN accuracy.

Frequency compensation for resistive voltage divider using specially shaped inner conductor

The main factor that slows down the high-frequency response of a resistive voltage divider (RVD) is the distributed stray capacitance (Cg) between the high-voltage-arm (HVA) and the grounded conductors, due to the charging and discharging of Cg through the high resistance RH of the HVA with characteristic time RHCg. Based on a RVD consisted of ceramic tube resistors, a compensation method utilizing the distributed capacitance between a specially shaped inner conductor and the HVA was proposed in this paper, which is more compact than grading rings and can work well with grounded shielding. The method was verified by electromagnetic simulation, which indicated a bandwidth improvement from 3 MHz to more than 1 GHz for the prototype RVD with grounded shielding. Experimental results showed that the 10%–90% rise time for a step input was improved by the compensating electrode from ∼90 ns to 1.25 ns. The main drawback of the method is the possible degradation of insulation when precise compensation is required.

AUTO-OSCILLATING MODE OF SCAN OF BUT END PROBE FOR DIAGNOSTICS OF BEAM-PLASMA DISCHARGE

This paper presents the result of experimental testing of the methodology auto-oscillating mode probe, which is based on a previously developed mathematical model of the secondary emission instability of a plasma-surface contact. The method of auto-oscillating mode probe is designed to measure the plasma parameters of beam-plasma discharge (BPD) in the near-axial zone of a beam-plasma installation with a longitudinal magnetic field. A scheme had been developed for measuring the current and voltage of the probe using a low-inductance resistive voltage divider, the Rogowski coil with the current shunt, and current meter on the Hall effect. The ion current density in the near-axial zone of the SPR was determined.

Design and Operation of First Egyptian IEC Fusion Plasma Device

In this paper, Egyptian first inertial electrostatic confinement fusion (IECF) device, constructed at the Egyptian Atomic Energy Authority (EAEA-IEC), is introduced the characterization of IEC Plasma Device. It consists of 2.8 cm stainless steel cathode, 6.5 cm anode diameter with 10 cm diameter 30 cm height vacuum chamber. The discharge current and voltage of plasma discharge has been recorded using current probe and resistive voltage divider respectively. The X-ray emissions in IEC plasma device were investigated by employing time-resolved detector. The temporal distributions of detected x-rays emission are occurring during the initial 1 microsecond. The calculated rate of DD-neutron generation using the same electrode configuration about 106 – 108 neutrons/second.

Self-Calibration and Verification of Phase Angle Errors of Two Voltage Dividers at High Frequencies

A set of cascaded inductive voltage dividers (IVDs) with a ratio of $2^{n}$ :1 and resistive voltage dividers (RVDs) with serial–parallel connection structure is presented in this paper. The IVD with the ratio of $2^{n}$ :1 is built with a $2^{n-1}$ :1 IVD and a binary IVD connected in the cascade structure. The phase angle errors of the IVDs are calibrated in a step-up procedure by using the three BIVDs in cascade connection as the reference standard. The phase angle errors of the RVDs can also be self-calibrated. The self-calibration results and uncertainties of phase angle errors of the IVDs and RVDs have been both given at frequencies up to 100 kHz. A closure measurement between the IVD with the ratio of 256:1 and the RVD with the ratio of 257:1 has also been done at frequencies from 25 to 100 kHz. The closure results show good agreement within 15 $\mu $ rad compared to the self-calibration results.

Harmonic Power Standard of VTT MIKES

This paper describes the new single-phase harmonic power standard developed at VTT MIKES. The standard is based on a custom digitizer, which is designed for both laboratory and on-site power metrology. Test signals are generated using a dual-channel arbitrary function generator, a voltage amplifier, and a transconductance amplifier. The reference voltage and current measurements are, respectively, based on a capacitive–resistive voltage divider and two different types of resistive shunt designs. Thorough characterization of the components is presented. Finally, a tentative uncertainty budget is drawn up for frequencies 53 Hz, 1 kHz, 10 kHz on power factors 1.0 and 0.0. The standard has an expanded uncertainty of 32 and $157~\mu \text{W}$ /VA at 10 kHz for power factors of 1.0 and 0.0, respectively.

Experimental Setup for Harmonic Impedance Measurement in a Real HV Power Grid

The article describes an experimental setup constructed for the verification of harmonic impedance (HI) measurement method in a real HV power grid. The setup is located in a 110 kV distribution substation in Poland. It includes voltage measurement circuits based on wideband resistive voltage dividers, multiple current measurement circuits, and distributed time synchronized data acquisition system. The whole setup is able to simultaneously sample 3 voltage and 12 current signals and record data on a dedicated data server. The details of the setup construction are presented. Some guidelines, based on experiences, are given on how to prepare such setup. Additionally a result of a preliminary experiment, in which the HI of the supply system was measured, is shown to confirm capabilities of the setup.

Low-Uncertainty Equality Between the Voltage-Dividing and Resistance Ratio of a DC Resistive High Voltage Divider

The comparison results for the resistance and voltage-dividing ratios of a direct current (DC) high-voltage divider at the low-voltage level were presented. The two ratios were equal within 0.3 × 10−6 for the 2250:1 ratio and within 0.5 × 10−6 for the 15,000:1, 13,500:1, 6750:1, and 675:1 ratios. The results show that the divider can be used as a reference voltage-dividing ratio device within a 0.5 × 10−6 agreement with sub-ppm uncertainty at low voltage, irrespective of which of the two ratios is selected. It was also confirmed that the two ratios were traceable to quantum Hall resistance and Josephson voltage standards with a 0.4 × 10−6 (k = 1) uncertainty level up to 1 kV.

Characterization of high-precision resistive voltage divider and buffer amplifier for ac voltage metrology

A high-precision voltage buffer and a 10:1 resistive voltage divider have been constructed for use in ac voltage and electrical power metrology. Long-term stability of the buffer's dc response has been demonstrated by two dc sweeps performed 20 days apart, with best-fit linearized gain varying less than 1 μV/V. The absolute ac gain has been measured using a high-precision digital multimeter for 10 Hz and 1 kHz with results consistent with dc within 5 μV/V. This value agrees with the characterization of ac–dc difference using thermal converters from different producers with a variety of resistance for various voltages from 1 V to 5 V. The ac–dc difference was further characterized better than 40 μV/V for the same voltages up to 100 kHz and better than 100 μV/V for 3 V at 1 MHz. Absolute ac gain and ac–dc difference has also been measured for the voltage divider and buffer combination from 10 V to 50 V, with similar agreement up to 1 kHz. The ac–dc difference from 10 Hz to 100 kHz of this combination shows an agreement well within 30 μV/V in this entire voltage span with a total response not exceeding 125 μV/V. This make the voltage divider and buffer combination suitable for sampling electrical powers for a wide range of voltages.

A laboratory study of environment and voltage effects on the thermal state of resistive voltage divider

There are currently no thermal self-diagnostics systems of instrument transformers operating in real time, as opposed to power ones, and thermal inspections are often carried out according to a maintenance schedule, which affects the reliability of electrical equipment. Therefore, an important task is to create such systems for digital instrument combined current and voltage transformers based on resistive dividers, which determine temperature values at several points, including the most heated element. The aim of this study is to obtain experimental data on the thermal state of a resistive divider exposed to environmental factors and voltage for developing a self-diagnostics system. The results are obtained by physical simulation of thermal conditions of the transformer and its elements in high- and low-voltage climatic chambers. The effects of the following factors of critical importance have been simulated: electric voltage, insolation, temperature and speed of the ambient air. Data processing was performed using the methods of probability theory and mathematical statistics. The time needed for the thermodynamic system to move to a steady heat exchange mode, and also the temperatures on the lower resistors and on the surface of the voltage transformer insulation cover have been determined. It has been established that thermal conditions are more significantly affected by the simulated voltage than by insolation. The study has shown that even in the most severe emergency operating modes, heating in the lower resistor does not exceed the critical value. It has been found that the thermal state of the transformer is significantly influenced by the simulated factors including directional insolation, which is not taken into account in the existing methods of calculating the thermal state of the instrument electrical equipment. The reliability of the obtained results is ensured by the fact that the simulation took into account significant factors. The results of the experiment will be used to develop a thermal self-diagnostics system for the digital transformer, which will improve the reliability of operation of such instrument equipment by allowing the personnel’s to give a rapid response to real-time information about the transformer thermal state.