Comparative analysis of IEC 61850 Edition-I and II standards for substation automation

Electrical energy is the backbone of our global society. Its reliable supply from the power utilities via complex network requires seamless control. Substation is a crucial element of power grid facilitating the efficient transmission and distribution of electricity to the consumers. In order to provide a standardized framework for substation automation the International Electro technical Commission (IEC) introduced the IEC 61850 standard for power grids. IEC 61850 Edition-I has established itself as a global communication standard for substation automation by integrating electrical equipment into control systems in power utilities. However the edition-I had encountered amounts of inconsistencies and shortcomings, to rectify them IEC 61850 Edition-II standard was released in June 2010. The edition-II proposes to boost the level of communication consistency by specifying network redundancy. The IEC 61850 consists of a group of standards, under which the IEC 62439 standard defines the Parallel Redundancy Protocol (PRP) and High Availability Seamless Redundancy (HSR) protocol to attain zero recovery time. This paper is a comparative study of IEC 61850 Edition-I and Edition-II which broadly focuses on the enhancement of communication reliability. Further we also discuss the future challenges and the methods to overcome them. The major challenge of handling of the duplicated data in the PRP and HSR mechanism has been discussed with the proposed solution of using a Link Redundancy Entity (LRE) and Redundancy Control Trailer (RCT). Also the edition-II expands its horizon from substation automation systems to other application areas (Distributed energy resources) which indicates the significance of IEC 61850 standards.