绝缘材料光声池的理论分析与实验验证

Simulation Analysis and Experiment Verification of Insulating Material-Based Photoacoustic Cell

高压套管是电力系统的核心部件,对高压套管的绝缘状态进行检测具有重要的实际意义。由于目前常见的绝缘状态在线监测设备难以适用于安装位置特殊、体型较小的高压套管,研发适用于高压套管的检测系统势在必行。相较于传统金属结构的光声池,采用全绝缘结构光声池能够在进行原位检测时不形成悬浮电位,从而能够规避在高压套管内引发局部放电等故障,是对高压套管绝缘状态进行检测的理论可行方案之一。探究了适用于高压套管检测的原位检测系统重要部件全绝缘结构光声传感器的可行性。分别从基本原理、仿真计算及实验验证三个方面对全绝缘结构光声池进行了分析及论证。首先,就光声池材料对光声信号的影响进行了理论分析,讨论了相较于传统黄铜材料,由绝缘材料石英制成的光声池可能存在的问题。然后,在此基础上采用COMSOL Multiphysics建立了共振式光声池的仿真模型并进行了声学和热学相关计算,对理论分析的结果进行验证,并分析了实际情况下石英光声池的理论表现。最后,建立基于石英光声池的光声光谱检测系统实验平台,结合波长调制及二次谐波方法对微量乙炔气体进行定量检测,用于对石英光声池的可行性进行验证。仿真计算结果表明,类似于黄铜材料,石英材料光声池同样具备对微量气体进行定量检测的能力。实验结果表明,基于石英光声池的检测系统对乙炔气体的检测极限能够达到0.16μL·L^(-1),满足相关标准中油浸式电气设备对乙炔检测的需求。因此,以石英为材质的共振式光声池具备应用于高压套管原位检测的潜力。

High voltage bushing is one of the core components in a power system.Therefore,it is with significant meaning to monitor the insulation status.However,current commercial equipment for online monitoring is not suitable for bushing with special locations and small sizes.As a result,developing a detection system for bushing specifically is necessary.In-situ detection is one of the theoretically feasible ways for bushing monitoring.Compared with metal material,photoacoustic cells made of insulating material can avoid floating potentials and following partial discharge.This paper studied the feasibility of insulating material-based photoacoustic cells.First,the influence of the material on the performance of photoacoustic cells was studied,and potential problems of photoacoustic cells made of insulating material quartz were discussed.Then,using COMSOL Multiphysics,the theoretical performance of quartz photoacoustic cells was simulated from both the thermal and acoustic sides.Finally,a detection system based on quartz photoacoustic cells was established to testify to the simulation outcome.The simulation results indicated that quartz-based photoacoustic cell was as capable as the conventional brass photoacoustic cell to detect trace gas quantitatively.Besides,the detection limit of the established detection system in this word could reach the level of 0.16μL·L^(-1),which could meet the relevant standard.Therefore,such insulating material-based photoacoustic cell is with the potential for in-situ detection of bushing.