Electrical Load Flow Analysis of 132/33/11 kV Port of Durban’s Substation

Abstract

The Port of Durban (PoD) is currently upgrading its existing power supply to a supply voltage of 132 kV. The existing 33 kV supply cables are old and have exceeded their designed life resulting in unplanned power outages. The existing 33 kV switchgear is old and obsolete as a result it is difficult to maintain. The existing maximum demand capacity will not be able to cater for the additional loads required for the planned expansion developments.The electrical load flow is a very important and fundamental tool for the analysis of any power systems and in the operations as well as planning stages. The electrical load flow study was conducted using PowaMaster software to analyse the behaviour of PoD’s electrical network post implementation of the new substation onto the currently existing network. In performing the electrical load flow study, load diversification is one of the critical input parameters that was considered because it is a true representation of the network behavior. The load forecasting was based on the planned developments commissioned between 2017 and 2027. The electrical load flow study was also to validate if all the new selected reticulation cables and transformers as part of the design have been correctly sized and will be able to operate reliably without compromising security of firm supply with the implementation of all the planned future loads. This report entails the results of the electrical load flow study that was conducted to analyse the voltage stability and system reliability of the PoD’s electrical network in conjunction with new 132/33 kV Langeberg Substation.