Neutralijännitetta

Neutralijännitetta, often translated as neutral voltage or neutral potential, refers to the electrical potential of the neutral conductor in an electrical system. In a three-phase AC power system, the neutral conductor is typically connected to the center point of the transformer's secondary winding, which is also grounded. This grounding establishes the neutral conductor at or near earth potential.

The purpose of the neutral conductor is to provide a return path for unbalanced currents in a three-phase system. In an ideal, perfectly balanced three-phase load, the currents in the three phase conductors would sum to zero at any given instant, meaning no current would flow through the neutral. However, in real-world scenarios, loads are rarely perfectly balanced, leading to a residual current that flows through the neutral.

The voltage on the neutral conductor is ideally zero or very close to it due to its connection to ground. However, factors such as unbalanced loads, harmonic currents, and impedance in the grounding system can cause the neutral conductor to have a non-zero voltage relative to true earth potential. This phenomenon is known as neutral voltage displacement or neutral shift. Excessive neutral voltage can pose safety risks, potentially causing shock hazards and damage to connected equipment, especially sensitive electronics. Proper grounding and system design are crucial to minimize neutral voltage issues.