Linjetilllinjespänningen

Linjetilllinjespänningen, often translated as line-to-line voltage, is a fundamental concept in three-phase electrical power systems. It refers to the voltage measured between any two of the three "hot" or "live" conductors in such a system. In a balanced three-phase system, these three voltages are equal in magnitude but displaced from each other in time by 120 electrical degrees. Consequently, the line-to-line voltage is also a sinusoidal waveform.

The line-to-line voltage is typically higher than the voltage measured between a single conductor and the neutral conductor, which is known as the phase voltage or line-to-neutral voltage. The relationship between line-to-line voltage (V_LL) and phase voltage (V_ph) in a balanced three-phase system is given by the formula V_LL = sqrt(3) * V_ph. This factor of the square root of 3 (approximately 1.732) arises from the vector addition of two phase voltages.

Understanding line-to-line voltage is crucial for selecting appropriate electrical equipment, such as motors, transformers, and switchgear, which are rated according to their operating voltage. The higher voltage available between lines is often utilized for industrial machinery and power transmission where more power is required. The distinction between line-to-line and phase voltage is essential for correct wiring and safe operation of three-phase installations.