Protection of HV systems: is simple and cheap good enough?

Due to the changes in the power supply industry, decisions about technical issues, like protection, are confronted with an increasingly economic dimension. Proposed improvements need a value for money motivation. On the other hand, the use of the power system is stretched to its limits, sometimes even reducing the redundancy, which leads to more severe demands on the protection system. The paper gives the results of a research project conducted for Dutch utilities. It is undertaken in order to find an optimal balance between costs and performance. The study compares different protection schemes, projected on the same high voltage power supply system