A case study of the impacts of small hydro power plants on the power distribution network with the combination of on load tap changers

The deregulation of the electricity markets and the advances in the power generation technologies together with financial and environmental concerns have positioned distributed generation as a very promising power generation alternative. Scope of this paper is to investigate some problems related to voltage quality when DG is implemented in a weak distribution network. The case under study is a 20 kV distribution network containing 17 small synchronous and asynchronous hydro generators. The voltage variation along the distribution network is examined under variable loading conditions, variable generation modes and by implementing voltage regulator, on load tap changer and compensation capacitors. Results show that the DG can act as a voltage supporting mechanism, together with the other regulating devices, while it is essential to investigate the reactive power flow in the network.