Ac Voltage Standards Research Articles

Application of inverter input rating method and standard AC voltage drop/over method on automatic transfer switch for hybrid powered e-bike charging station

Automatic transfer switch (ATS) is useful for integrating two different energy sources can be applied to e-bike charging stations. Renewable energy sources from sunlight using 2×100 Wp photovoltaic (PV) modules as the main source in this study, as well as grid energy sources functioned as backup energy. This ATS uses inverter input rating methods and standard AC voltage drop/over, a novelty of this study. The amount of current during testing is up to 14.09 A. The value of the inverter input voltage affects the quality of the inverter output voltage, there is a stability of the inverter output voltage from the AC voltage standard ±5% of the, lowest voltage value of (Vo_inv) = 223.9 V and the highest value (Vo_inv) = 226.1 V, at the time of (Vi_inv) max = 14.15 V and (Vi_inv) min = 12.66 V. It can be concluded that the ATS works in the PV position of the supply to the e-bike load, in the PV state it can produce power of a maximum value of 135.9 W at 11:25 am and is at the lowest power of 31 W at 03:31 pm. This ATS device in the switch mode successfully implemented a duration range of 10-21 ms, during the transfer of energy.

Wideband AC Voltage Standards

This article presents a critical review and comparison of constructions and metrological properties of contemporary wideband standards for AC voltage. It focuses on selected thermal voltage converters (TVCs) used in alternating current-direct current (AC-DC) transfer voltage standards and for the most precise measurements of AC voltages up to approximately 100 MHz. These devices serve as primary AC voltage standards at National Measurement Institutes (NMIs).

Frequency-dependent component of AC-DC transfer difference of a redesigned calorimetric thermal converter

This article presents an analysis of the frequency-dependent component of the AC-DC transfer difference of a calorimetric thermal voltage converter (CTVC) with substantially reduced DC reversal error. It contains an analysis of the effect of this reduction on the AC-DC transfer difference. The analysis was based on the mathematical model of a CTVC waveguide, which was extended by estimation of the residual parameters of the CTVC heater (microwave rod resistor) using the finite element method (FEM). The results of the analysis were validated by laboratory measurements. The article also contains the uncertainty budget of the AC-DC transfer difference of the new CTVC. Despite its high thermal time constant, the CTVC is currently one of the most accurate AC voltage standards in the frequency range from 1 to 100 MHz.

Sub-GHz resolution line-by-line pulse shaper for driving superconducting circuits

We demonstrate a sub-GHz resolution, fully programmable Fourier-domain pulse shaper capable of generating arbitrary optical pulse patterns for superconducting circuit platforms. This high resolution allows line-by-line pulse shaping of a 1 GHz-spaced comb, and the pulse shaper can accommodate an optical bandwidth as large as 1 THz, which represents the highest resolution programmable line-by-line pulse shaping to our knowledge. Linear optical sampling with a dual-comb system confirms independent control of 1 GHz-spaced optical lines, and the low phase noise of the pulse shaper is characterized. We apply the pulse shaper as an optical drive for an array of Josephson junctions operating at a temperature of 4 K, where cryogenic photodetection of pulse doublets with user-defined separation characterizes the Josephson junction response. Furthermore, we demonstrate a pulse-density modulation pattern of 4 ps duration optical pulses that can serve as the high bandwidth drive of a quantum-based Josephson arbitrary waveform synthesizer. By leveraging the exquisite control, large bandwidth, and low noise of photonics, this represents an important advance toward the realization of high power and high spectral purity AC voltage standards at gigahertz frequencies without requiring 100 GHz bandwidth driving electronics.

Research on the Application of Quantum AC Voltage Standards

Research on the Application of Quantum AC Voltage Standards

Enhanced operation frequencies of bipolar double-flux-quantum amplifiers fabricated using 10 kA cm−2 Nb/AlO x /Nb integration process

We have demonstrated digital-to-analog (D/A) operations using single-flux-quantum (SFQ) pulse-frequency modulation (PFM) D/A converters for future AC voltage standards. In this paper, for the improvement of SFQ-PFM D/A converters, we investigated a double-flux-quantum amplifier (DFQA) and a magnetically-coupling SFQ driver/receiver circuit (MC-SFQ-DR) fabricated using a 10 kA cm−2 Nb/AlO x /Nb integration process. The critical current density J c of 10 kA cm−2 was four times larger than that of the integration process we had used. A DFQA and an MC-SFQ-DR included unshunted Josephson junctions, and therefore, it was unclear if the high-J c process improved their performances. We measured test chips cooled in a liquid helium bath. The maximum input voltages for a +20 fold and a −20 fold DFQA were 147 and 126 μV, for which the corresponding Josephson frequencies were 70.9 and 61.1 GHz. It was confirmed that the operation frequencies of the DFQAs and MC-SFQ-DR were improved approximately two-fold.

Quantum-Derived Voltage Waveform Synthesis With Pulse-Driven High-Transition-Temperature Josephson Junctions

Microwave-driven Josephson junction arrays are the basis for dc and ac voltage standards, whose accuracy derives from quantized voltage pulses. These pulses are also used to synthesize voltage-noise reference signals that are used in noise thermometry systems. This article describes our recent demonstration of voltage synthesis in a high-transition-temperature YBa 2 Cu 3 O 7-δ junction circuit.

Comparison of a Thermal AC Voltage Standard in the 1–30-MHz Frequency Range

This article presents results of a comparison of a traveling ac voltage standard, which was a fused-silica planar multijunction thin-film thermal converter (PMJTC) developed at the National Institute of Standards and Technology (NIST). The ac–dc voltage-transfer difference of the standard was measured at 2 V and selected frequencies from 1–30 MHz against primary thermal ac voltage standards at the Silesian University of Technology, Istituto Nazionale di Ricerca Metrologica, RISE Research Institutes of Sweden, and Trescal A/S Silkeborg.

Interlaboratory Comparison of Thermal AC Voltage Standards

Abstract The article presents results of comparison of the thermal converter of nominal input voltages equal to 10 V from the set of Polish National AC voltage standards, maintained at the Central Office of Measures in Warsaw, with the primary AC voltage 5 V standard, developed and maintained at the AC-DC Transfer Laboratory of the Department of Measurement Science, Electronics and Control at the Faculty of Electrical Engineering of the Silesian University of Technology in Gliwice.

Determination of AC–DC Transfer Difference of Calculable Thermal Voltage Converters in 1–30-MHz Frequency Range

This paper presents the results of determination of the ac-dc voltage transfer difference of two calculable thermal ac voltage standards, developed at the Silesian University of Technology, Gliwice, Poland, in 1-30 MHz frequency range. Two experimental methods confirmed with high accuracy the results obtained from the mathematical model.

Determination of Frequency-Independent Component of AC–DC Transfer Difference of SUT Calculable AC Voltage Standards

This paper describes the determination of value of frequency-independent component of ac–dc voltage transfer difference of two calculable thermal ac voltage standards developed and maintained at the Silesian University of Technology Gliwice, Poland. According to our research, the value of this parameter determined with ac–dc transfer measurements is $0.0~\mu \text{V}$ /V with combined standard uncertainty ( $k = 1$ ) equal to $0.3~\mu \text{V}$ /V. The obtained results were validated with fast-reversed direct current method and will be used to supplement the uncertainty budgets of these standards. The presented method does not require expensive quantum ac voltage standards.

Comparison of a Planar Thin-Film Thermal AC Voltage Standard up to 1 MHz

This paper presents results of a trilateral comparison with a traveling ac voltage standard comprising a planar thin-film thermal converter. The ac-dc voltage transfer difference of the standard was measured at 1 V and at selected frequencies from 20 Hz to 1 MHz against primary thermal ac voltage standards at the Silesian University of Technology, Istituto Nazionale di Ricerca Metrologica, and Trescal.

Calculable AC Voltage Standards for 10 kHz-1 MHz Frequency Range

This paper describes two calculable thermal ac voltage standards developed at the Silesian University of Technology in Gliwice, Poland. The design and mathematical model of these standards made calculation of their ac-dc transfer differences with very low uncertainty possible, comparable to the uncertainty of the best available calculable ac voltage standards in the 10 kHz-1 MHz frequency range. The correctness of the results of the ac-dc transfer difference calculation was also confirmed experimentally.

Design and Operation of a Double-Flux-Quantum Amplifier Excluding Flux Bias Lines

In addition to their fast switching with low power dissipation, precise voltage generation is a unique feature of single-flux-quantum (SFQ) circuits. This feature is attractive for realizing ac voltage standards consisting of SFQ-based digital-to-analog converters (DACs). Among several key components in SFQ-based DACs, a double-flux-quantum amplifier (DFQA) is a potential candidate to amplify the output voltage. In this paper, we present a redesigned DFQA without flux bias lines. We found a parameter set that provided wide bias margins and zero-flux-bias operation. Improved bias regions were numerically demonstrated, whereas a ±20-fold DFQA excluding flux biases was fabricated using Nb integration technology and tested in a liquid helium bath.

An AC Josephson Voltage Standard up to the Kilohertz Range Tested in a Calibration Laboratory

This paper describes the development of an automated ac quantum voltmeter toward a turnkey system, which can be used for calibration of common dc and ac voltage standards. The setup was tested in an accredited commercial calibration laboratory to characterize Fluke 5700A calibrators and voltage standards. The measured voltage in dependence on various parameters is presented in the range of dc to 2 kHz with amplitudes up to 10 V. The uncertainty components are discussed, and the system relevant Type B uncertainty for ac voltage calibrations is 0.15 μV/V. The contribution of the leakage current is investigated in detail and found to be notable for frequencies above 1 kHz due to parasitic capacitances. The combined measurement uncertainty for calibration ac voltages is less than 0.62 μV/V (k = 1 and 40 Hz-1 kHz) and is limited by the noise of the calibrator. Comparison measurements at Physikalisch-Technische Bundesanstalt have been done and confirm the system reproducibility.

4-bit Bipolar Triangle Voltage Waveform Generator Using Single-Flux-Quantum Circuit

SFQ digital-to-analog converters (DACs) are one of the candidates for AC voltage standards. We have proposed SFQ-DACs based on frequency modulation (FM). Bipolar output is required for applications of AC voltage standards, while our previous SFQ-DACs generated only positive voltages. In this paper, we present our design of a 4-bit bipolar triangle voltage waveform generator comprising an SFQ-DAC. The waveform generator has two output ports. Synthesized half-period waveforms are alternately generated in one of the output ports. The bipolar output is realized by observing the differential voltage between the ports. We confirmed a 72-μVPP bipolar triangle voltage waveform at the frequency of 35.7Hz.

交流電圧標準を導く薄膜型サーマルコンバータの開発

Thermal voltage converters have been widely used in the electric standard field as a major method to derive AC voltage standards from DC voltage standards. However, there are only a limited number of organizations that are capable of fabricating thermal voltage converters. Furthermore, establishing AC-DC voltage standards has been constrained by the lack of high-quality thermal converters. High-quality thermal converters are used only by national metrology institutes (NMIs) because the conventional thermal converters are too fragile for many calibration laboratories. The National Institute of Advanced Industrial Science and Technology (AIST) has developed new thin-film multi-junction thermal converters(TFMJTCs) to realize a reliable high-performance thermal converter. Development of a durable TFMJTC with a heater on an aluminum nitride (AlN) substrate is expected to make significant contribution to Japanese calibration laboratories.

Improved Electrothermal Simulation for Low-Frequency Characterization of a Single-Junction Thermal Converter

We perform a numerical simulation for the low-frequency characterization of a single-junction thermal converter down to 1 Hz using an improved electrothermal model. The low-frequency characterization of a thermal converter below 10 Hz is of great importance for linking ac-dc transfer standards and low-frequency ac voltage standards based on sampling methods. One feature of our model is the incorporation of the heat capacity for the thermocouple, which has previously been neglected to reproduce an accurate thermal time constant. Our model also includes the temperature dependence of the Seebeck coefficient in the thermocouple in addition to the temperature-dependent material parameters of the heater. To verify the simulation results, the calculated results are compared with the experimental results, which shows that our improved model well reproduces the measured data below 1 Hz. The estimated uncertainty of the simulated ac-dc transfer differences is 49 μV/V at 4 Hz. These results suggest that our model is a useful predictive tool at low frequencies.

Wideband High Stability MEMS-Based AC Voltage References

This paper presents the high level of stability of voltage references operated in alternating current (ac) and based on the pull-in effect in split-finger microelectromechanical systems (MEMS). It shows results of both electrical and mechanical characterizations, as well as the development of optimized readout electronics. The new aspects in this paper are related to the new architecture of the MEMS allowing minimizing the effect of leakage capacitances on the stability of the voltage reference and avoiding compensating any “built-in voltage” generated at metal–semiconductor interfaces. Hence, the voltage stability of MEMS devices, designed to serve as ac voltage standards ranging from 2 to 14 V, has been measured over more than 150 h with a relative deviation from the mean value not exceeding $1 \times 10^{-6}$ ( $1\sigma$ standard deviation) at 100 kHz. The temperature dependence of these devices has been found ten times smaller than those previously reported. In addition, MEMS-based references are theoretically independent of frequency beyond the mechanical resonant frequency. The frequency stability has been successfully tested between 40 and 300 kHz.

International comparison of quantum AC voltage standards for frequencies up to 100 kHz

This paper presents results of an international comparison of two quantum AC voltage standards based on pulse-driven Josephson arrays. The two systems differ in several hardware and software characteristics as well as in the level of automation, features which can influence the accuracy of transferring the quantum-standard voltage value to a calibrated instrument. The comparison was performed at 100mV, 20mV and 12mV, at frequencies between 2.5kHz and 100kHz. An electronically-aided thermal transfer standard was used as a travelling standard. At the most accurate voltage and frequency point, 100mV at 2.5kHz, both laboratories agreed to better than 1 part in 106.