Infrared Applications In Transmission System Surveys

Abstract

Five California Utilities participated in an electric power transmission and distribution system survey in the late fall of 1987. The survey consisted of visual and Infrared (IR) inspection of 12.5-kV to 230-kV AC transmission lines and equipment. This paper summarizes the results of the survey, including a cost/benefit analysis. The participating utilities, under Western Area Power Administration's sponsorship, were the City of Lodi, City of Roseville, Plumas-Sierra Rural Electric Cooperative, Sacramento Municipal Utility District, and Sierra Pacific Power Company. Three hundred miles of line and thirty substations were inspected using a helicopter and a high resolution infrared camera with visual recording capabilities. The transmission and distribution system covered a broad range of terrain; valleys, foothills, and mountains. All five utilities recognized the value of the IR inspection. The procedure gave the maintenance staff advanced notice of problem areas such as (1) loose connections on switches, (2) unbalanced lines, (3) poor splices, and (4) capacitor and transformer bank malfunction. In addition, the staff saw its potential in environmental and safety applications. The initial data shows an increased capacity carrying and reliability providing capability of about 50 KW per 100 transmission line miles. This capability increase results in a B/C ratio of about three. Other applications in transmission system surveys are worthy of study. These applications include power theft and vandalism. Also, the Utility can use technology as an effective public relations tool with customers by providing services such as roof and building envelope inspections.