Phase shifting transformers (PST) are crucial components in the ongoing strive for improved AC network efficiency. Increasing amounts of transmitted energy push the networks to the limit, increasing the risk of network instability.
PSTs allow controlling the power flow in the transmission grid independently of the generation. By avoiding system overloads and instabilities protect transmission lines and HV equipment from thermal overload, improve transmission system stability and control the power flow between different networks, for parallel long distance overhead lines or for parallel cables.
PSTs are highly specialized pieces of equipment that require leading- edge design and manufacturing skills combined with stringent quality control. They are highly complex power transformers, with more windings and tap changers than traditional power transformers and a large number of connections between the three-phases.