Recent Findings in the Long-term and Short Circuit Behavior of Power Connections and their Relevance for Testing

摘要

Facilities for the transmission and distribution of electric energy are increasingly utilized due to fundamental changes in power generation and transportation as well as the rising power consumption worldwide. An essential part of those systems are non-arcing power connections such as plug-in type, bolted and crimp connections. The long-term behavior of the mentioned types of power connections depends on the operation loads as well as on specific load conditions, for example short circuit currents or tension loads. The suitability of a certain connection design is proofed in type tests. The procedures and requirements defined therein are suited for many applications. However, these procedures do need a certain degree of freedom in the definition of loads and often do not consider combined load situations. Recent findings reveal that these aspects can have a significant impact on the long-term behavior. Therefore, this paper describes processes that might take place in the connections' contact spots depending on the selected load condition as well as on the categorized power connection types. Various experimental results and calculations exemplify the described processes. Based on this, recommendations are given for testing and evaluating power connections under specific load conditions.