A method for overcoming thermo EMF of shunt connected meters for measuring electric energy

Abstract

The thermoelectric potential mainly exists in the contact surface of different metal materials, from a few micro volts to dozens of micro volts, which is not easy to eliminate and the measurement is complex. It introduces large error to the calibration of the shunt connected electric energy meter. In this paper, the current reversing method is used to measure the positive and reverse power, and then the influence of the thermoelectric potential on the mV voltage of the shunt is eliminated by the software revision, so as to improve the precision of the detection of the shunt electric energy meter. The starting time is calculated by measuring the time of receiving a pulse in a positive and reverse direction to improve the accuracy of the starting test. At the same time, the low thermal potential is reduced by placing the shunt in the uniform temperature non conducting material. In the end, the improved electrical energy verification device is used for experimental testing to provide a higher precision technical means for tracing and detecting the source and detection of indirect access DC power meter.