Earthquake disaster prevention system built-in switchgear and control method thereof

Disclosed are a switchboard comprising an earthquake disaster prevention system and a control method thereof capable of preventing overvoltage generated by voltage imbalance and maintaining normal voltage when disconnection of a neutral line is generated in the switchboard and of preventing a disaster by automatically blocking the power of a building when an emergency is generated by the earthquake. The switchboard comprising the earthquake disaster prevention system comprises a power supply device, an earthquake sensing sensor, and a neutral line recovery device. The power supply device comprises a main breaker and a mold case current breaker (MCCB). The earthquake sensing sensor senses the intensity of the earthquake. The neutral line recovery device reduces image high-harmonics by operating a zigzag transformer when over current flows in the neutral line of the power supply device. When the voltage imbalance is sensed by sensing the voltage imbalance for each phase of power supplied from the power supply device, the neutral line recovery device the power imbalance as the short-circuit of the neutral line and recovers the neutral line by connecting one end of an inductance to the recovered neutral line. The neutral line recovery device calculates a current progress level based on the intensity of the earthquake sensed in the earthquake sensing sensor. When the current progress level is over a predetermined danger progress level, the neutral line recovery device outputs a power blocking signal. [Reference numerals] (210) Short-circuit detector; (220) Current detector; (230) Controller; (240) Neutral line recovery device; (250) Alarm generator; (260) Alarm release signal input unit; (300) Earthquake sensing sensor