相位匹配原理在油中局放超声阵列信号测向中的应用

Application of Phase Matching Principle in Detecting Direction of Arrival for Partial Discharge's Ultrasonic Array Signals in Oil

电气设备油中局放超声阵列定位是目前的研究热点,而高精度的局放超声阵列信号测向结果(波达方向估计)是准确定位的基础。首先简要介绍了相位匹配原理,并分析了基于该原理的局放超声阵列信号波达方向估计方法;然后针对不同阵列孔径和不同信噪比,仿真研究了该方法的波达方向估计精度,结果表明,在小阵列孔径(4×4排列)、低信噪比环境中,该方法的估计误差很小,明显优于相同环境下的多重信号分类(MUSIC)算法;最后搭建了实验平台,在信噪比约为20dB的环境中进行研究,多次实验的估计误差为3°左右,验证了该方法的正确性。

Partial discharge （PD） location in oil using ultrasonic array signals is the hotpot of research at present, while the accurate estimation of direction of arrival （DOA） is the base of it. First, the phase matching principle is introduced and then the estimation method of DOA for ultrasonic array signals of partial discharge based on it is proposed; Second, the estimated accuracy of this method is simulated with different array sizes and signal to noise ratio （SNR）, the results show that the error of the method this paper proposed is small in environment of small array size （4 x 4） and low SNR, which is better than the multiple signal classification （MUSIC） algorithm; Finally, a set of PD detecting system is established, and several experiments were done based on it in environment of 20 dB. The results from some experiments show that the errors of DOA were about 3°. It indicates that the estimation method proposed in this paper is with a good accuracy.