Electrospun CuO/ZnO heterostructure sensors for highly sensitive and selective acetylene detection in transformer diagnosis

Abstract

The acetylene gas generated within transformers is a hazardous gas that can imply the risk of explosion even at low concentrations. This research aims to develop a metal oxide semiconductor-based acetylene gas sensor optimized for condition monitoring of power transformers. Existing acetylene gas sensors are developed considering the ambient air environment (21% oxygen) and are unsuitable for transformer applications, highlighting the need for sensors optimized for transformer environments. To overcome the limitations of previous research, this dissertation employs two main approaches. In Chapter 2, the sensor's performance was validated by establishing a material composition that achieves selectivity for coexisting gases at high concentrations (hundreds of ppm) within power transformers while detecting low concentrations of acetylene gas (1-10 ppm) in the transformer environment (2% oxygen). The sensor's operating temperature and stability were also considered. In Chapter 3, two different sensing platforms were utilized to compare and evaluate the gas sensing characteristics of acetylene, observing variations based on platform differences. The sensing platforms were integrated into a probe-type sensing module, designed and fabricated for easy insertion into transformers, and the sensing performance was evaluated by detecting dissolved acetylene gas in actual transformer oil using a transformer simulator. This research provides insights into the detection of dissolved acetylene gas in transformer oil using the developed sensor and establishes a foundation for the practical application of high-performance acetylene gas sensors in condition monitoring of power transformers.