FACTS Technology and Controllers
1. FACTS Technology
Definition: Alternating current transmission systems incorporating power electronic-based and other static controllers to enhance controllability and increase power transfer capability.
2. Need for FACTS Technology
To control the power flow by controlling the line impedance, voltage magnitude and phase angle. In an AC system, the power flow depends on the bus voltages (V1, V2), the reactance of the line (X), and the phase angle difference between the buses (δ). The power flow in AC system (Fig. 1) can be expressed by,