kulmamuuntaja

Kulmamuuntaja, in electrical engineering, refers to a transformer designed to introduce a controlled phase shift between its input and output voltages. The term is Finnish for “angle transformer,” and in English-language literature it is often called a phase-shifting transformer or angle transformer. Its primary purpose is to control power flow in alternating current networks by altering the phase angle difference between sending and receiving ends, thereby increasing transfer capacity and reducing congestion on transmission lines.

Construction and operation take advantage of standard transformer principles enhanced with phase-shifting capabilities. Kulmamuuntajat may be built as conventional transformers with a phase-shifting winding arrangement or as dedicated phase-shifting units that use specific connection schemes to create the desired phase displacement. The adjustable phase shift between primary and secondary is typically tunable and can be operated in on-load or off-load conditions, depending on the design and the required control performance. Protection schemes for these devices are built to handle the dynamic interactions with the grid and include coordination with line protection and system controls.

Applications are primarily found in high-voltage substations and transmission corridors where precise control of power flow is needed. They are used to alleviate congestion on tie-lines, to optimize the use of existing assets, and to improve stability and reliability in multi-area power systems. Kulmamuuntajat enable utilities to re-distribute power flows during peak demand or contingency situations without immediate network reinforcements.

See also: phase-shifting transformer, power flow control, transformers, transmission system planning.