Analysis of switching over-voltages in a three-ended 400 kV cable system

The development of an electromagnetic transient model to assess potential transient switching issues on a proposed three-ended 400 kV cable circuit is described. The key features of the PSCAD-EMTDC simulation tool and the methodology of model development and testing are discussed. Typical study results and the overall conclusions drawn from these are presented. The paper demonstrates how analysis and modelling studies play an important role in the technical feasibility assessment and design of future infrastructure works such as substations and cable networks. The analysis confirms that it is feasible to operate the circuits as a three-ended arrangement via a simple T-point without overstressing the primary plant.