The security system of a soft redundancy sub-station

PURPOSE: A security system for a distribution panel capable of supporting dualization is provided to prevent an accident such as hacking by comprehensively establishing a security system and a dualization system, and to reinforce stability through an access control authentication control. CONSTITUTION: An input and output security apparatus(100,100') is dualized to protect power system instruments in a distribution panel, establishes a VPN(Virtual Private Network) security tunnel with an upper layer system, detects abnormal condition such as malfunction based on the detected data from various sensors and switches when abnormal condition occurs. A security unit performs security system encryption for a relay(10) side of the power system instrument, and establishment of a VPN security tunnel. An input and output unit detects access, opening, malfunction, and communication abnormal condition, is connected to a communication port of the relay, detects malfunction and communication abnormal condition of the relay, and judges the abnormality and transmits an alarm message to a server or an administrator terminal depending on the state of the abnormal condition. A control unit sets a system function such as dualization interlocking through switching based on the input signal by a user, and includes a heartbeat protocol for mutual switching. [Reference numerals] (AA) Outside of a distribution panel(a component of a system for protecting power system instruments) box; (BB) Intranet; (CC) Virtual internet modem(192.158.0.1); (DD) Wired router; (EE) 2.2.2.1(virtual IP); (FF) Inside of a distribution panel(a component of a system for protecting power system instruments) box;