Intensity Modulated Photothermal Interferometry-based Acetylene Detection in Insulation Oil
Real-time tracking of acetylene in transformer oil is of great significance for ensuring the stable operation of oil-immersed transformers.The novel photothermal interference(PTI)optical technique,characterized by"zero background",high sensitivity,non-contact measurement,and immunity to electromagnetic interference,has tremendous potential in dissolved gas analysis of transformer oil.In this paper,an acetylene sensing scheme based on Herriott gas cell and intensity-modulated photothermal interference technique is proposed.First,the process of acetylene photothermal effect excited by single-beam is modeled and simulated to study the temperature distribution,pulse excitation dynamic response,and frequency response of sinusoidal excitation.Parameter optimization experiments are conducted,revealing that increasing the pump intensity effectively enhances the photothermal phase,while higher modulation frequency hinders sufficient excitation of the photothermal effect.The detection of acetylene in oil under simulated fault conditions is carried out,and the PTI system achieves a detection sensitivity of 0.5(mV⋅L)/μL with a lower limit of 0.94 μL/L,which meets the needs of monitoring acetylene in transformer oil with high voltage levels during operation.The feasibility and potential of PTI technique in detecting dissolved gases in oil are demonstrated.
oil-immersed power transformerdissolved gas analysisacetylene detectionphotothermal interferometrySagnac interferometer
万方数据
维普
