基于特高频定向天线阵列的变电站局部放电定位MUSIC算法

MUSIC Algorithm for Partial Discharge Location in Substation Based on Utral High Frequency Directional Antenna Array

多重信号分类(multiple signal classification,MUSIC)算法采用全向天线作为阵列阵元,为提升算法的抗干扰能力和定位精度,针对变电站局部放电检测采用定向天线阵列进行定位的具体应用,将天线方向图增益作为阵列流形系数,提出并推导了用于定向天线阵列定位的MUSIC算法,在运用克拉美罗界和二阶统计信噪比估计理论分析算法定位误差基础上,通过搭建仿真模型进一步验证算法的性能。仿真结果表明,对于常规选定频带的局部放电信号,基于定向天线的MUSIC算法可在天线方向图增益大于1的来波方向范围内提升定位精度,且定位精度与天线增益大小成正相关。采用所设计的方向图增益达6 dB的定向天线阵列,在信噪比为0 dB的条件下信源定位误差为0.806°,而经典MUSIC算法的定位误差达到17.403°。

Multiple signal classification(MUSIC)algorithm uses omnidirectional antennas as array elements.In order to improve the anti-interference ability and positioning accuracy of the algorithm,this paper is aimed at the practical application of partial discharge detection in substations using directional antenna arrays for positioning;moreover,the pattern gain is regarded as the array manifold coefficient,this paper put forward the MUSIC algorithm for directional antenna array positioning.On the basis of analyzing the positioning error of the algorithm by using the Cramer-Rao Lower Bound and the 2-order statistical signal-to-noise ratio estimation theory,the performance of the algorithm is further verified by building a simulation model.For the partial discharge signal of the conventional selected frequency band,the simulation results show that the MUSIC algorithm based on the directional antenna can improve the positioning accuracy in the range of the incoming wave direction where the antenna pattern gain is greater than 1,and the positioning accuracy is positively related to the antenna gain.When the directional antenna array designed in this paper with a directional gain of 6 dB is utilized,the signal source positioning error is 0.806°under the condition of signal-to-noise ratio of 0 dB,while the positioning error of the classic MUSIC algorithm reaches 17.403°.