Upgrading existing power supply at the Port of Durban.

Abstract

The Port of Durban’s (PoD’s) power supply is from EThekwini Electricity (EE) at a supply voltage of 33 kV via two main intake substations that is Stanger Street Substation (STS) and Durban Harbour Intake (DHI) Substation. The supplied power in the Port is stepped down from 33 kV to 11/6.6 kV electrical network. The firm supply capacity for each of these substations is limited to 17 MVA, which is no longer sufficient to supply the PoD because EE’s 33 kV electrical infrastructure and supply cables have reached the end of their design lifespan. The existing power supply capacity limit is under threat due to that; it will not be able to meet the additional load required for the planned developments and expansion plans in the Port. System strengthening and enhancements are required in order to improve the reliability of the electrical network. Increasing the electrical supply to and within the Port will ensure a stable and reliable electrical supply. This research is based on the increase of power supply in the PoD to 132 kV electrical network based on the projected load requirements for planned developments in order to strengthen and increase reliability of the network. The 132 kV electrical network was implemented in PowaMaster software to perform the load flow analyses. Various load flow scenarios were investigated and from the results obtained it was evident that 2 x 132 kV 40 MVA transformers will be capable to carry the total projected Port load reliably and the electrical network will be stable. Detailed analysis and results of different scenarios investigated is contained in this dissertation. An automatic and interactive SCADA model of the physical power systems electrical reticulation network was developed using Schneider CitectSCADA Software. The implemented 132/33 kV substation network model together with the hardware IEDs i.e. VAMP 255, VAMP 259, MiCOM P122 and GE F35 Feeder management protection relays provided functions for control, data acquisition, monitoring, graphical displays, event capturing, alarming, trending and data storage. Communication between the implemented SCADA system and the IEDs was achieved via a communication architecture implemented that took into consideration Modbus RTU, DNP3 and IEC 81650 communications protocols. The substation model implemented was tested for operation at different operating and fault conditions. The effective operation was proven for circuit breaker operation, alarming, circuit breaker fail, overcurrent, earth fault and circuit breaker trip coil supervision under local or remote mode. Results obtained are presented and discussed.