Reducing the cost of maintaining the frequency stability using dc grid protection

This paper quantifies the operational cost of maintaining the frequency stability in a scenario when the largest loss of infeed originates from an offshore grid. The loss of infeed is considered only temporary, by taking advantage of fast dc grid protection. The power restoration curve is used to define the impact of protection on the stability and sensitivity analysis of its parameters is performed. A North Sea based grid topology shows a significant benefits of using a faster and more selective protection. Consequently, a FS protection strategy is recommended for the topology. The topological changes have a considerable impact on the cost and a meshed system that can restore the power to a higher level is highly cost effective.