8. Communication Standards in Virtual Power Plant

Data such as demand response events in OpenADR is exchanged in XML format and messages are defined in XML Schema Definition Language (XSD) [W3C standard, XML Schema Definition Language (XSD) 1 Part 1: Structures. W3C Proposed Recommendation (2012). http://​www.​w3.​org/​TR/​2012/​PR-xmlschema11-1-20120119/​]. There are two query method PUSH type and PULL type. The difference between PUSH type and PULL type is the communication protocol corresponding to the subject when the message is transmitted from VTN to VEN. In the case of PULL, VEN is main component, and message notification is periodically requested (polled) to the VTN, and HTTP is used as the communication protocol. In the case of the PUSH type, the VTN is the main component, the message is directly notified to the VEN, and HTTP or XMPP (Extensible Messaging and Presence Protocol) [P. Saint-Andre, Extensible Messaging and Presence Protocol (XMPP): Core. RFC61020 (2011)] is used as the communication protocol.