Study of fault levels on supply networks

This paper assesses the repercussions of factors such as voltage, power density, total system size and network configuration on fault levels. The analysis is made for idealised, regular networks with uniform generation and load density, but the trend of the solutions is such that the results give a useful guide for practical networks, particularly as regards long-term development strategies. The main conclusions reached are that a terminal fault level exists for such a uniform system which, will not be exceeded, irrespective of further geographical extension of the network; that this fault level is closely related to the power density; that one of the most effective ways of containing fault level is to control the load density by choice of a suitable configuration; and finally that the life expectancy of an increased switchgear rating, with or without change of voltage, is predictable.