High-Precision Current Measurement Technology of Charging Pile Based on AC/DC Comparator and its Remote Calibration Method

The introduction of the dual-carbon policy has accelerated the development of the electric vehicle industry and the improvement of technology. Among them, the improvement of charging infrastructure has always been a major issue in the industry. In this paper, a high-precision current measurement technology and its remote calibration method for charging piles based on Alternating Current/Direct Current (AC/DC) comparator are proposed. The technology uses precision current conversion standard, digital multimeter and high-precision current standard meter as measurement standards for measurement and calibration. Through supporting high-precision AC current standard meter, digital oscilloscope, DC current ripple tester and other auxiliary equipment, the calibration of three parameters of DC current standard source current indication error, short-term stability and ripple content is realized. This remote calibration method can not only greatly reduce the cost, improve the efficiency of metrological verification, but also effectively improve the accuracy and reliability of metrological verification. Through this technology, the electric energy metering device of the charging pile can realize real-time and accurate electric energy calibration without interrupting the normal operation, which provides a strong guarantee for the measurement accuracy of the electric vehicle charging pile.