RESTful access to power system state variables

This paper shows one possible way to enhance power system software integration by leveraging RESTful web services in the process of publishing power system state variables, i.e. the results of simulation functions used in power system analysis.¹ Different simulation functions are executed in power system control centers with various goals: optimize network utilization, find critical elements, plan future extensions, etc. Most of these functions base their operation on the results of state estimation and/or load flow. The implementations of these base functions most often come from different software vendors using, in general, different communication mechanisms. Even if the base functions are provided by a sole vendor, the various functions relying on the results of these base functions are most probably offered by different software companies. For this reason, it is necessary to have a standardized method for exchanging state variables between parties. In this paper, we propose a lightweight mechanism, reminiscent to the mechanisms of the World Wide Web, for publishing state variables. The proposition is actually based on existing IEC standards and drafts. The final goal is to allow solution providers to develop a planning and simulation environment for control centers utilizing components made by separate organizations.