Introduction to IEC 62746-4 communication for demand response

This paper introduces the IEC 62746 series that defines interfaces between a grid operator system and multiple Customer Energy Management Systems located at residential, commercial, and industrial customer sites. IEC 62746-4 documents possible message exchanges and leverages information models from the IEC 62325 set of standards developed for bulk-power market exchanges. One of the fundamental ideas is that almost all information exchanges can be described in terms of just two technical roles: the Operator Role and the Resource Role. This allows demand response use cases to be implemented using sequences of a small library of message structures. Sequences are expected to start with messages that describe the characteristics of an energy resource or an aggregation of energy resources. A flexible time-series message structure can be used for several purposes, such as to describe a resource’s historical consumption or forecasted consumption. The standard defines three other message structures to suit the requirements of different regions and various types of demand response programs. There are messages to (a) publish grid service prices, (b) communicate bids, offers, or self-scheduling information, and (c) send setpoints for absolute or relative changes in power transfers.