With the large-scale integration of distributed photovoltaic power generation and wind power into the grid

as well as the increasing prevalence and widespread distribution of new loads such as electric vehicles

the number of power grid current monitoring points has grown exponentially

which has led to how to achieve the reliable and accurate current monitoring at massive nodes in the power grid becoming one of the major challenges in electrical measurement technology. This paper presents the design and implementation of a tunnel magnetoresistance (TMR) array-based current sensing device for distributed measurement of dynamic load current. It analyzes the impact of eccentricity in the measured current conductor and external interference on current measurement errors. A TMR array-based current sensor and a remote current data transmission device are developed

enabling field tests simulating dynamic load currents in high-power substations and distribution transformers. Field test results demonstrate that the developed TMR array-based current sensing device can reliably measure line current with an accuracy of approximately 1%

fully meeting the requirements for monitoring dynamic load currents at multiple grid nodes

which provides a reference for advancing distributed wide-area measurement technology for current in novel power systems.