765 kV series capacitors for increasing power transmission capacity to the Cape Region

A total of six series capacitors are coming on line in 2012 in the 765 kV national grid in South Africa, to strengthen the power transmission network in the Western Cape region. The installations, which form part of an initiative to increase power transmission capacity to the Cape region, will allow the utility more flexibility and reduce its reliance on existing local power generation. The ratings of the series capacitors range from 450 Mvar up to approximately 1300 Mvar.With series capacitors, the capability of already existing power lines can be increased considerably, thereby decreasing the need for new lines in cases where the need for power transmission capacity has grown. Likewise, in green-field projects, the amount of transmission lines to take care of a certain amount of power transmission can be kept to a minimum. Series capacitors have undergone strong development in recent years, as well. A hardware platform named Fast Protective Device (FPD) has been developed, and successfully introduced into the commercial series capacitor market. The paper presents the ESKOM 765 kV series capacitor project, offers some background regarding grid performance requirements, highlights a few vital steps in project execution, as well as gives some salient design features of the series capacitors.