基于EFPI传感器的立体形阵列传感器对局放测向的仿真分析

局部放电超声阵列定位技术是将传感器阵列与阵列信号处理方法相结合。本文采用非本征法布里帕罗干涉（Extrinsic Fabry-Perot Interferometric，EFPI）的光纤超声传感器，其灵敏度高，不受电磁干扰的影响；并充分发挥EFPI传感器可放置于油中的优势，改进阵列结构。设计了4阵元EFPI超声传感器正四面体结构阵列，将其置于油箱内部检测局放超声信号，然后利用多信号分类算法(Multiple Signal classification，MUSIC)算法对局放源进行测向；并与平面2×2阵列进行对比；最后，针对阵元位置误差进行校正。结果表明：该阵列传感器能够在油中检测到信噪比较高的局部放电信号；且较传统平面阵，具有更高的测向准确度；尤其在阵列盲区方面，立体型阵列传感器可有效地实现空间多角度的信源测向。并利用TCT算法对阵元位置误差进行校正，提高了测向精度，满足了实际工程需要。

Simulation analysis of PD Direction Finding Based on Stereo Ultrasonic Array Sensor of EFPI

The partial discharge ultrasonic array positioning technique combines the sensor array with the array signal processing method. In this paper, the Extrinsic Fabry-Perot Interferometric optical fiber ultrasonic sensor was used. It has the high sensitivity and is not affected by electromagnetic interference. And take full advantage of the EFPI sensor what can be placed in the oil to improve the array structure. First a four-element EFPI ultrasonic sensor array of regular tetrahedral structure was designed, which was placed in the fuel tank to detect the local ultrasonic signal. Then, the MUSIC algorithm was used to measure the local discharge source; and compared result with the 2×2 planar array. Finally, the correction is performed for the position error of the array element. The results show that the EFPI sensor stereo array can detect the partial discharge signal with high SNR in the oil, and has higher direction finding accuracy than traditional planar arrays. Especially in the aspect of array blind zone, the stereo array can effectively realize spatial multi-angle source direction finding. And TCT algorithm is used to correct the position error of the array element, which improves the direction finding accuracy, and satisfy the actual project needs.