midzyfazowego

Międzyfazowego, commonly written as międzypfazowy or międzynfazowy in Polish, is a term used in electrical engineering to describe quantities, phenomena or measurements that occur between two different phases of a polyphase electrical system. The most frequent reference is to the voltage or current that exists between two phases (interphase or line-to-line quantities).

In a three‑phase system with phase voltages Va, Vb and Vc, the interphase voltages are Va − Vb, Vb − Vc and Vc − Va. For a balanced system with sinusoidal phase voltages separated by 120 degrees, the magnitude of each interphase voltage is equal to the phase‑to‑neutral voltage multiplied by the square root of three. For example, in a star-connected system with phase‑to‑neutral voltage 230 V, the line‑to‑line voltage is about 400 V (VLL = √3 × VLN).

Interphase concepts are important for the assessment and protection of electrical networks, measurement of line-to-line quantities, and fault analysis. Interphase faults, such as short circuits between two phases, produce large currents and require dedicated protection schemes. In transformer and reactor design, interphase connections and tap arrangements influence how interphase voltages behave under load and during transients.

Usage notes: in Polish technical literature the terms międzypfazowy or międzfazowe describe relationships or quantities between phases, and should be distinguished from phase-to-neutral (fazowy) quantities.