Uncertainty analysis of AC charging pile calibrators for electric vehicles

To address the need for accurate evaluation of the metrological performance of AC charging pile calibrators for electric vehicles, this paper systematically analyzes the sources of measurement uncertainty based on the working principle of AC charging pile calibrators. By establishing a mathematical model, the uncertainty components of the key parameter-electric energy-are quantified, including standard device error, measurement repeatability, environmental factors, and photoelectric control. Using empirical data and the GUM method, the expanded uncertainties under reference conditions and at the extreme temperature of -20°C are determined. The results show that the calibrator’s uncertainty primarily depends on the accuracy of the standard source and measurement repeatability. Under reference conditions, the expanded uncertainty is 1.4×10⁻⁴ (k=2), while at the extreme temperature, it increases to 1.5×10⁻⁴ (k=2). This study provides a theoretical basis for reliable evaluation of the metrological performance of AC charging pile calibrators and has practical significance for improving the accuracy of value transfer in charging infrastructure.