Impact of distributed generation on voltage profile in 38kV distribution system

This paper presents a case study of the integration of a relatively large amount of distributed generation (DG) into a weak distribution network (DN). It addresses the problem of voltage rise mitigation in DN with DG connected. The main focus is on a comparison of methods to increase the integration capacity of DG into DN and the technical requirements from the Distribution System Operator (DSO)´s point of view. The paper considers voltage rise issues in real-life DN that incorporate different types of DG such as Combined Heat and Power (CHP) and wind power generation. The objective of this study is to propose an approach that will demonstrate the impact of DN components on voltage profile violation caused by the connection of DG. The aim of the proposed approach is not to control the bus voltage but to guarantee that DG injection alone will not cause a significant voltage rise: a solution in which DNs are kept to their traditional task of voltage regulation for load demand. The approach is discussed from the perspective of effectiveness and adequacy. Validation of the study is carried out by using the ERAC power flow analysis software on a seven busbars DN which resembles a part of a real network consisting of number of DG units connected at the 38kV voltage level.