Optimal Design of Differential Sensor Array for Interference Elimination of Noninvasive Multicore Cable Current Measurement

Magnetic sensor arrays have been widely applied in noninvasive current measurement of multicore cables. However, existing sensor arrays designed for multicore cables are susceptible to the effects of external interference sources. Recently various noninvasive sensing devices with interference-elimination strategy are designed but do not make the fullest use of differential sensor array. Thus, a current measurement method using differential signal of sensor array is proposed to eliminate interference in this article. Besides, an optimal design method of differential sensor array is put forward to find out optimal design parameters of the sensor array which maximize the interference elimination. A two-level optimization model is built to solve the parameter optimization problem. The upper level is a design parameter optimization model, which determines the optimal design of the sensor array. The lower level is a current measurement problem, in which differential current measurement situations with interference are simulated to obtain current errors that affect the results of the upper model. Based on this method, an optimal design of differential sensor array is obtained by numerical simulations. Laboratory experiments verify the feasibility and effectiveness of the proposed method. The results show that the optimal design of the sensor array has an improved resistibility to magnetic interference.