Future transmission network operation and design standards to support a low carbon electricity system

Increased connections of wind power in the Great Britain (GB) transmission system had triggered the need to review the fundamental principles behind the deterministic Great Britain Supply Quality and Security Standards (SQSS) that has been used for more than 5 decades. This review analyses the necessary upgrades to improve the efficiency of transmission system operation and capacity required to accommodate the present and future generation system. This paper in particular addresses a number of issues raised from the applications of deterministic SQSS and its operation and design efficiency concerning the best usage of N-k policy type. With respect to the United Kingdom (UK) transmission system operation, deterministic standards have been used to determine secure maximum levels of power transfers across a particular boundary. Our studies indicate that the deterministic standards are too conservative. This leads to over requirement of transmission capacity in planning timescales or significant constraints to access remote wind power in operational timescales. As an alternative, the use of an integrated reliability and cost-benefit framework to optimize the level of transmission system security has been developed. A wide range of studies have been carried out to analyze the benefits of this approach in the UK. The results indicate the need to move towards this integrated approach in order to maximize the value of transmission and to speed up the connections of wind power.