Smart Tie-Line Control Using Controllable Network Transformers

Increasing load growth, decreasing investments and increasing penetration of dynamic sources and loads have severely increased the stress on the electric grid. This growing stress has forced operators and regulators to think of delivering energy in a smart, controllable and reliable way to the customers. Tie-lines connecting two systems are one of the traditional methods used by utilities to improve the system reliability. However, often specially during contingencies, tie-lines get overloaded due to the lack of power flow controllability through them. Controllable Network Transformers (CNTs) are smart assets which can be realized by augmenting existing Load Tap Changing (LTC) transformers in order to achieve power flow control. This paper proposes the use of CNTs in tie-lines to make them smart and controllable, without compromising the system reliability.