Overvoltage happens in a condition where the voltage is increased and exceed its design limit. This situation may lead to harmful damage to machines or related equipment that connected to the system. Overvoltage can exist in a form of transient, voltage spike or permanent, depending on its duration. Types of overvoltage consist of lightning overvoltage and switching overvoltage. Overvoltage that caused by lightning is considerate as natural phenomena, while switching overvoltage exists from the system itself, either by the interruption of faults or inappropriate connection of circuit breaker contacts. This paper is discussed about overvoltage phenomenon including causes and effects of overvoltage and overvoltage protection towards power system.
