Development and Implementation of a 1.5 MW Inverter and Active Power Filter System for the Injection of Regenerated Energy in a Spoornet Traction Substation by Heinrich Daniël Fuchs-University of Stellenbosch--South Africa

Development and Implementation of a 1.5 MW Inverter and Active Power Filter System for the Injection of Regenerated Energy in a Spoornet Traction Substation 

Author

Heinrich Daniël Fuchs 

Thesis presented in partial fulfilment of the requirements for the degree of Master in Science in Engineering at the University of Stellenbosch 

 Summary 

Spoornet is one of South-Africa’s largest railway companies. It is very important to operate the railway system as cost effectively as possible. A large portion of the railway operates from 3 kV DC traction supplies. One method of cost saving is to utilise the regenerative braking mechanism of the electric trains. By using this method the train decelerates by using the electric motor of the engine instead of the mechanical braking system. When the electric motor is used for braking, the momentum of the train pushes the motor which then generates electric energy. This regenerated energy flows through the overhead lines back to the nearest substation. Previously this energy was just dumped in large resistor banks and has gone to waste as heat. The aim of this thesis was to implement a system that will inject the regenerated energy back into the Eskom supply network. This will save the cost of the electricity that is supplied back to Eskom as well as the cost saving on the mechanical braking system of the train. Furthermore the system will be an active power filter to eliminate the harmonic pollution on the Eskom network caused by the rectifier in the traction substation.

LINK: https://pdfs.semanticscholar.org/14d8/9e433721e5d51fe380b95d32a6d2ac3b97c7.pdf