What is the main purpose of a phase-shifting transformer?

The primary purpose of a phase-shifting transformer is to control the flow of megawatts (MW) in a transmission path. These transformers modify the phase angle between the voltages on either side of the transformer, which directly influences power flow in interconnected transmission networks. By altering the phase difference, operators can direct power flow away from congested lines and optimize the use of the existing transmission infrastructure.

Phase-shifting transformers are especially useful in systems with significant power transfers and can help manage the balancing of loads and generation. This capability makes them a strategic tool in ensuring reliability and efficiency in power transmission, thereby enhancing the operational stability of the grid.

Other options mention functions that are typically associated with different types of equipment within the transmission system. For example, absorbing VAR (Volt-Ampere Reactive) is usually the role of capacitor banks or synchronous condensers, while reducing voltage and regulating reactive power losses pertain more to voltage regulation and reactive power compensation methods. These roles are distinct from the primary function of phase-shifting transformers, which is focused on managing active power flow.