Development and application of DC current sensor

Abstract

Current sensing and measurement technology is the basis and reliable support for power grid system control, which directly affects the safe operation of electrical equipment in the system. Aiming at the difficulty of reliable and rapid detection of DC current in the distribution network, this paper develops the design of a DC instrument transformer based on tunneling magnetoresistance. First, the hardware design scheme of the DC instrument transformer is proposed, and the working process of the instrument transformer is given. Next, the key design technology of DC instrument transformer is given in Simulink, and the power flow analysis model of the distribution network is established to simulate and verify the detection function of the instrument transformer. Finally, the designed DC instrument transformer is used for DC current detection in the Suzhou medium-low voltage DC distribution network demonstration project. The results show that the DC instrument transformer can quickly and accurately detect the amplitude of the DC current, which can strongly support the power control and dispatch of the distribution network.