Katuo Sugawara

Niew Apparatus for Detecting Transformer Faults

A diagnostic apparatus for detecting gases dissolved in transformer oil is described, in which a tetrafluoroethylene-perfluoroalkylvinylether copolymer membrane is used to separate H2 CO, CH4, C2H2, C2H4, and C2H6 from the oil. These gases are detected with a new gas detector, which consists of a catalytic gas sensor and a gas chromatograph using air as the carrier gas. Using the gas concentration, the apparatus automatically determines whether a transformer is operating normally or not and, in the latter case, what kind of fault may have occurred. By the above diagnostic apparatus, a transformer could be diagnosed simply and inexpensively. This apparatus should prove useful for identifying what kind of fault may have occurred.

New Apparatus for Detecting H2, CO, and CH4 Dissolved in Transformer Oil

This report presents a new method of separating H2, CO, CH4, C2H2, C2H4, and C2H6 dissolved in transformer oil and detecting H2, CO, and CH4, in which a tetrafluoroethylene-perfluoroalkylvinylether copolymer membrane is used to separate gases from the oil. The quantities of H2, CO, and CH4 that permeated through the membrane were relatively large. These gases were detected with a new gas detector, which consists of a catalytic gas sensor and a gas chromatograph, and which uses air as the carrier gas. Compared with conventional methods of gas analysis, H2, CO, and CH4 dissolved in transformer oil can be analyzed simply and inexpensively with this method. As a result, this new method should prove useful in determining whether a transformer is operating normally or not.

Apparatus for Continuously Monitoring Hydrogen Gas Dissolved in Transformer Oil

This report presents an apparatus for continuously monitoring of hydrogen gas dissolved in transformer oil, in which a polyimide membrane is used to separate the hydrogen from the oil. The hydrogen is allowed to permeate through the membrane and contact a gas sensor every 72 hours. The characteristics of the permeation of the hydrogen gas through the polyimide membrane and of the detection of the hydrogen gas by the gas sensor are described under various conditions. Problems encountered when the apparatus is installed on a tran are also studied and solved. As a result, this new apparatus was found useful in determining whether a transformer is operating normally or not.