Hongtao Huang

Traceability of digital electricity meters

We propose a scheme for traceability of digital electricity meters. For standard digital electricity meters, the analog-based method should be used. For installing digital electricity meters, the digital-based method can be used. In the process of quantization of sampling values, rounding error brings uncertainty to the computation of power. In this paper we analyze the uncertainty caused by rounding error by simulation.

Phase comparator based on binary inductive current divider up to 200 kHz

A phase comparator has been developed to compare the phase angle of AC shunts at frequency up to 200 kHz at National Institute of Metrology (NIM) in China. The comparator can supply two currents in which one of the current is two times of the other. With this comparator, the phase angle of two AC shunts can be compared both in nominal current.

Calibration method for digital energy meters in digital substations

Digital energy meters are used in digital substations to measure electric energy, which receive IEC 61850 digital input. The traditional calibration methods for analog energy meters are not applicable to digital energy meters. In this paper we propose a method to calibrate digital energy meters.

Resistive voltage divider with two stage voltage buffer for harmonic measurement

The shielding, insulating bracket protection and two stage voltage buffer technology is adopted by resistive voltage divider. It can be used for the harmonic voltage measurement. The ratio error of the voltage divider is within 10 ppm from DC to 10 kHz.

A transfer standard of harmonic voltage and current at power frequency

A transfer standard of harmonic voltage and current based on the synchronized sampling technology was developed in NIM China. The working fundamental frequency of the transfer standard is 45 to 65 Hz; the highest order is within 50th; the range is 120 V and 5 A. The accuracy of the harmonic voltage is 30 µV/V (of the fundamental voltage) and the harmonic current is 40 µA/A (of the fundamental current).

Synchronized sampling controller for harmonic measurement

A synchronized sampling controller based on direct digital synthesis was developed in NIM China. Its used in the transfer standard for harmonic measurement. The working fundamental frequency of the controller is 45 to 65 Hz; the trigger output frequency is 11.5 kHz to 16.6 kHz due to the 256 times of the fundamental frequency. The resolution of the controller is less than 1 μHz.

A coaxial ac shunt with calculable ac-dc difference

The development of a coaxial ac shunt with calculable ac-dc difference was described in this paper. The shunt was built with minalpha wires instead of commercial available resistors. The ac-dc difference of the shunt was calculated to be less than 1×10−6 at frequency up to 100kHz.

Dynamical waveforms and the dynamical source for electricity meter dynamical experiment

Dynamical loads and dynamical power sources become more and more frequent in grids. Energy measurement under dynamical conditions is an important problem. In this paper, we describe the modulated waveforms as dynamical waveforms used in electricity meter dynamical experiment. And we designed a dynamical source to output different kinds of modulated waveforms.

A new method to compare two thermal current converters at common ground at frequency up to 200 kHz

A new method to measure two thermal current converters at common ground by means of binary inductive current divider has been employed and compare with traditional voltage mode. The measurement results of two methods has been given at frequencies up to 200 kHz, and shown well agreement in frequency response against 1 kHz.

A new method to measure millivolt ac voltage at frequencies up to 200 kHz

A new method to measure millivolt ac voltage accurately has been proposed. The method is based on the use of a binary inductive current divider and current shunts with known ac-dc difference, to calibrate Fluke792A at ranges from 100 mV to 1 mV at frequencies up to 200 kHz.