INTERCONNECTED SYSTEM SWITCHING DEVICE AND POWER CONTROL SYSTEM

An interconnected system switching technology is provided which maintains, when a malfunction of a power system interconnected with a power generator occurs, power supply from the power generator by disconnecting the unstable power system causing the malfunction, thereby contributing to the stabilization of the power system. A device includes a malfunction detector 62 connected with a power generator 3 and a power system 1, also connected with a power control device 50 interconnected in accordance with a reference waveform created based on information input from the power system 1, and which detects a malfunction of the power system 1, and a connection switcher 63 which switches information for creating the reference waveform to information from an auxiliary system 2 other than information from the power system 1.