Distributed generation with voltage control capability in the low voltage network

Abstract in Undetermined
Small-scale distributed generators connected to
the low voltage network are generally operated with unity
power factor. However, controlling their reactive power
injection would have an impact on the voltage at their
connection point, if the network is sufficiently weak and
inductive. The purpose of this paper is to investigate how a
small-scale distributed generator connected to a low voltage
network through a power electronic converter can be controlled
to improve the voltage quality at its connection point.
The possibility to control the voltage at a point in the low
voltage network by reactive power injection is limited by two
factors, the small rating of the distributed generator compared
to the short-circuit power at its connection point and the
resistive nature of the low voltage cables. Here, a scheme for
inductively decoupling the distributed generator connection
point from the network is proposed and evaluated. For this
purpose, an inductance is placed between the network and the
generator, allowing voltage regulation by reactive power
injection.
Simulation results and lab measurements show that the
proposed scheme improves the voltage quality at the
microturbine connection point.