The Influence of Phase-shift Transformer Regulation on Power Flows in Eastern Croatian Transmission System

In the alternating current systems, due to insufficient possibilities of electric energy storage, generation and load have to be in balance at all times. When an adequate power generation is possible, the active power flows from the area of higher generation to the areas where power demand is increased. For that flow, the active power uses any disposable parallel routes through the power network. The presence of large power and low impedance transmission lines highly contribute to the forming of the loop through which the power flow is to pass. In explanation, in every transmission system there are some smaller and larger loops through which an uneven and unregulated power flow passes. By introduction and liberalization of electricity markets, separation of generation, transmission and distribution, and increase in the interchange of electric energy among the subjects on the market, there appeared the need for an efficient power current management in transmission networks. Phase shifting transformers may be used in power flow control in a complex power network very efficiently