Research on Self-Balancing Error Measurement Method for High-Resolution Current Self-Calibration System

To meet the error current measurement accuracy requirements of existing high-precision power-frequency current proportional self-calibration systems, a precision error current measurement method based on dual closed-loop feedback control is proposed. By employing a high precision current comparator as the ampere-turn error balancing device, the constructed differential current vector and the measured differential current vector are injected into the balancing device to set its zero-detection winding to zero, and measure the amplitude and phase of the error current signal indirectly in the calibration system. This method achieves precise construction of the error current vector through a dual closed-loop control strategy. Test results demonstrate that the error measurement device developed based on this method can meet the resolution requirement of 1 × 10−7 magnitude. This device provides technical support for enhancing the capability of national power frequency high-current proportional standard devices in subsequent stages.