**1. Introduction**

The Smart Grid combines electricity and IT infrastructure to integrate and interconnect all users (producers, operators, marketers, consumers, etc.) in order to efficiently balance demand and supply over an increasingly complex network. The smart grid software architecture is visualized as interconnecting sub-systems like Generation, Transmission, Distribution, and Utilization (GTDU). ISO/IEC/IEEE 42010 defines a software architecture as "a fundamental concept or properties of a system embodied in its elements, relationships, and in the principles of its design and evolution". A software reference architecture is a generic architecture for a class of information systems that is used as a foundation for the design of concrete architectures from this class [1]. Smart grid is viewed as a software intensive system in which majority of devices and components contain electronics and software. Smart grid software architecture is characterized as a large scale, multi-disciplinary, highly interconnected, data driven system. Research in smart grids has seen a flurry of proposals

and experiments to explore software architecture techniques. Cloud interface with grid sub-systems is another important theme in smart grid research articles. The architectural standards (National Institute of Standards and Technology (NIST), International Electrotechnical Commission (IEC)) define the guiding principles to the evolving smart grid software structure. In this paper, we attempted to group and investigate the research articles based on structure of software architecture for smart grid applications.
