This Software Requirements Specification defines the functions of a simulation power grid model. The model defines grid control functions that focus on real-time control and related communication of information among entities that share the operation of the power grid. Deregulation of the power markets necessitates increased communications among entities who have economic motivation to restrict access to important information from other market participants. New power market concepts will impact how planning and real-time control are performed. The simulation power grid model provides the tool for investigating issues of distributed computing, data sharing, data access, communication system capacity, and communications reliability. The model enables researchers to develop intelligent distributed control agents for managing Area Control Error and transmission security. The software requirements specification is defined using a subset of the Unified Modeling Language, a class diagram describing all of the objects along with their attributes, methods, and some modified use cases. The work described in this report was coordinated by the Consortium for Electric Reliability Technology Solutions on behalf of the Assistant Secretary of Energy Efficiency and Renewable Energy, Offce of Power Technologies of the U S . Department ofEnergy under Contract No. DE-ACO4-94AL85000.