Comparative analysis between conventional voltage control using reactors and continuous voltage control using TCR in the Romanian transmission grid

This paper deals with voltage regulation issues based on compensation reactors in the 400 kV network of the Romanian Transmission Power System. For secure operation reasons, voltage regulation plays an important role in a power system. As over- or under-voltages occurs due to the reactive power surplus or deficit, shunt reactors are employed to maintain the voltage within admissible limits. Currently, 100 MVAr reactors are switched on/off to regulate the voltage in the 400 kV nodes. However, large voltage spikes are experienced, causing dangerous stress on the switching equipment. The aim is to adapt the actual fixed reactors in some power system nodes with thyristor controlled reactors (TCR) or a combination of a smaller fixed reactor and a TCR. Dynamic simulations and load flow calculations have been carried out to show these differences using Eurostag and Neplan simulation software on the Romanian Power System database.