用于油中局部放电定位且可重复布置的超声阵列与超高频复合传感器设计

Design of Re-locatable Ultrasonic Array and Ultra High Frequency Combined Sensor for Partial Discharge Location in Oil

局部放电(PD)是电力变压器绝缘劣化的主要原因,对局部放电进行定位有助于加强电力系统的安全运行。为此,研制了一种用于变压器中局部放电定位的、可重复布置的复合传感器,并对它进行了实验研究。该传感器由13阵元的L形超声阵列与超高频电磁传感器共形地组成,应用高阶累积量处理技术对L形阵列进行扩展后可使之具有97个虚拟阵元的性能,提高了超声阵列的孔径和方向锐度。在局部放电实验平台上进行了定位实验,结果表明该复合传感器能很好地识别及定位单个或多个局部放电源,定位的平均相对误差分别为2.1%和5.1%。对较少阵元数的阵列实施虚拟扩展利于形成微型化复合传感器,为阵列技术在电力设备监测中的实用化奠定了基础。

Partial discharge （PD） is a main reason for the deterioration of power transformer insulation. Locating PD helps the safe operation of power systems. Therefore, we designed a re-locatable combined sensor to locate PD in transformer, and tested the sensor by PD locating experiments. The sensor is comprised of a conformal L-shape ultrasonic array of 13 array elements and an ultra high frequency （UHF） electromagnetic sensor. Being expended with high-order cumulants processing technology, the L-shape array can function as 97 virtual elements, which considerably improves the aperture and direction sharpness of the array. Moreover, PD locating experiments were carded out on a PD experiment platform. The results show that the combined sensor can distinguish and locate one or multiple PD sources effectively： the two kinds of locations have average relative errors of 2.1% and 5.1%, respectively. Virtually expanding an array with relatively few elements helps to design a miniaturized combined sensor, providing a foundation for practically applying array technology in power equipment.