Glossary of Electrical Terms in English—U
U
Ultra high voltage — extremely high voltage
Unattended substation — Unattended substation
Unbalance current — unbalance current
Unbalanced conditions — unbalanced mode
Unbalanced Short Circuit — Unbalanced short circuit
Unblock - unblock (unblock)
Underdamping — weak damping
Under excitation-underexcitation
Under frequency load shedding — AFC
Underfrequency relay — underfrequency protection relay
Underground cable — cable line
Underground substation — an underground substation
Underground system — electric cable network
Shortage (for remote protection system)
Faulty phase — undamaged phase
Unidirectional — one direction
Unidirectional current — current in one direction
Unimeter — multimeter
Continuous work - continuous work
Uninterruptible power supply — guaranteed power supply
Unloading — Unloading
Unloaded line — unloaded power line
Unmanned — no personnel on duty
Unmanned substation — unmanned substation
Unstable — Unstable
Unused - no taps
Unwanted operation (of protective equipment)
Upper harmonics — higher harmonics
City network — city distribution network