Study of information model for wide-area backup protection agent in substation based on IEC61850

Abstract

Agent-based wide-area backup protection (WABP) systems have been studied to improve the security of power system in recent years. IEC61850 has become an approved international communication standard for substation automation system. In order to make WABP device conform to the developing of substation automation system, the information model of wide-area backup protection based on IEC61850 is proposed in the paper. According to a kind of WABP algorithm, a decentralized and distributed architecture of WABP multi- agent system is given, in which the negotiation between protection agents is peer-to-peer manner. The WABP agent residing in protection IED (Intelligent Electronic Device) is regarded as a special logical node. The collaboration relations and information flows between WABP agent and conventional logical nodes are analyzed. The functions of WABP IED can be divided to three layers: interface layer, advanced process layer and basic computing layer. The remote message transferring principle for WABP agent in different substations is studied. The negotiation messages, which include staged distance protection actions, synchronous current signals and the fault judgments for transmission line, are organized with GOOSE or SAV. HDP or TCP is adopted to transmit the messages among the substations according to the types of messages. The communication agent in communication manager machine is responsible for forwarding remote messages from/to WABP IED. The information model for WABP agent has been designed and validated in EPOCHS platform. The work may provide a reference for the developing of wide-area protection device.