Date of Award


Document Type

Master Thesis

Degree Name

Master of Engineering (Research)


Electrical & Electronic Engineering

First Advisor

Mr. Sreto Boljevic


There are numerous aspects of a distribution network that must be studied in order to determine the maximum size of distributed generation that can be accommodated on the distribution network before supply standards are breached. Voltage rise is one of the main aspects of concern when connecting a distributed generator to a distribution network and this thesis develops the understanding of this phenomenon and concludes with a real life study.

Mathematical and computer simulation software examples within this thesis demonstrate how voltage rise can be reduced to the maximum allowable limit, a major concern if the capacity of a distributed generator unit is greater than the local load demand capacity of the feeder it is connected to, which is often the case especially with weak rural networks. The thesis assesses the various options a distribution system operator planner has available to them when determining the least cost technically acceptable method for reducing voltage rise to an acceptable level. Some methods of voltage rise mitigation discussed in this thesis are not approved methods in Ireland although they are discussed and analysed in many technical publications.

The thesis concludes with a study of a voltage rise that is caused by the introduction of a distributed generator unit exporting onto a 38 kV feeder in Ireland. Each option is studied and discussed and the findings of these technically acceptable options are ranked from a distribution system operator’s point of view. The financial assessment of these options is based on the agreed Commission for Energy Regulation costs with the Distribution System Operator in 2008. The overall results are then ranked by the criteria of least cost technically acceptable. This is the option that is then presented to the independent power producer. The independent power producer must assess this solution from financial cost, planning permission acquirement and length of project completion perspectives.

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