MAINLINE - Multivariate condition monitoring of high voltage overhead power lines

For the reliable operation of overhead power transmission lines, network operators are required to monitor environmental factors affecting the transmission network. These environmental factors include e.g. ice accretion on power lines and the environmental induced pollution of insulators. Ice accretion leads to an increase in the weight load on the support elements, which in the worst case can lead to the collapse of entire sections. Contamination on insulators reduces the insulation strength thus lowering the operational reliability of power transmission. Water films on the lines cause another relevant effect, which leads to increased corona discharges. This results in an increased emission of ultraviolet light as well as in an increased sound emission. Both effects are considered as environmental pollution, for both humans and wildlife. All three effects show strong dependencies on the surface condition of the line or the system component. However, there is currently no suitable measuring method available, which allows for a continuous and versatile monitoring of conductors and insulators. In addition, the quantitative relationship between the characteristics of surface layers (quantity, type, electrical properties, etc.) and the degree of impact on the operating condition has not yet been thoroughly investigated. The project MAINLINE therefore pursues two main objectives to enable better monitoring of overhead transmission lines. A self-sufficient sensor system for monitoring and evaluating the condition of surfaces of overhead line components is developed. The new measuring system will then enable a qualitative evaluation of the relationships between the surface layer and its effects. Based on field measurement data, these correlations will be investigated by means of statistical analysis. Basic research must therefore be conducted in the fields of sensor technology for the detection of surface layers, sensor systems for high-voltage environments and energy harvesting technologies. The methods are validated by means of demonstrators in high-voltage experiments. The results of the research activities are new metrological methods for the condition assessment of environmental influences on high-voltage elements and methods for the scientific investigation of surface effects.