De Villiers, Louw Nicolaas Francois2006-10-262006-10-262006-10-26http://hdl.handle.net/10539/1450Faculty of Engineering and the Built Environment; School of Electrical and Information Engineering; MSC DissertationIn the recent past the Eskom network operated out-of-step at three occasions. Eskom questions whether the out-of-step relays responded as they should have. This is based on the fact that not all the out-of-step relays operated during these events. This dissertation shows that shunts can make the impedance locus behave nonclassically to the extent that the present practices Eskom uses for out-of-step relaying become inappropriate for application at certain busbars of the network. This is illustrated by showing that when the characteristic of the relay at Hydra, situated on the Mpumalanga side of Hydra, is set using the classical approach, the mentioned relay will not detect swings that have their electrical centre south of Hydra. A modified two generator model is used to show the effect shunts have. The phrase “improved two generator model” refers to this model. The improved two generator model is derived to represent the section of the Eskom network that links Mpumalanga to the Western Cape.38969 bytes65134 bytes91744 bytes54698 bytes108705 bytes45507 bytes99044 bytes58534 bytes1460470 bytes760280 bytes548606 bytes3406195 bytes162033 bytes98109 bytes150156 bytes156270 bytes284874 bytes281550 bytes156663 bytes88903 bytes161631 bytes216774 bytes141770 bytesapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfenEskom networkEskomrelaysout-of-step relaysbusbarsHydraThesis