Toward standards for dynamics in future electric energy systems: The basis for plug-and-play industry paradigm
Abstract:
In this talk we propose that by taking a step back and understanding the fundamental physics of interconnected electric power systems one can begin to think systematically about the role of both competitive and cooperative control, and their pros and cons for these rapidly evolving systems. To support this, we organize our presentation in several parts: 1) physics and operation of power grids; 2) the role of control; 3) systematic specification of performance objectives (dynamic standards) for plug-and-play operations; 4) use of cyber for implementing standards (sensing, communications and control architectures for supporting implementation of these standards); and, 5) illustration of how several industry problems can be solved when following proposed plug-and-play standards for dynamics (use of power electronics for transient stabilization during faults and sudden equipment failures; use of PMUs for ensuring voltage and frequency quality by an intelligent balancing authority (iBA)—generalization of today’s control areas; storage control in microgrids/systems with small inertia).
In the first part we give a somewhat new, dynamic systems view, of physical operation in several qualitatively different power grids (bulk power regulated; bulk power with markets; hybrid mix of emerging grids; micro-girds for developing countries; and micro-grids for developed countries). The physical operation dictates how to define internal states of given (groups of) physical components and the interaction variables between different (groups of) physical components. Based on understanding physical principles, we propose a new state space model of an interconnected grid comprising (groups of) different physical components. This model has a transparent physical interpretation, and, it is, therefore used as the basis for explicit performance specifications in terms of interactions of components. Performance specifications become standards for plug-and-play dynamic interactions of components (behavior) over several time horizons within an otherwise complex dynamical grid, which, when followed, ensure system-wide performance. We emphasize that the proposed approach is a framework for thinking about the necessary specifications in future electric energy systems, which enables both choice of technology at the (groups of) component levels and, minimal interaction specifications to align these with the performance of the over overall system. It is not a specific method. This framework could possibly overcome the roadblock of integrating distributed local grid technologies with the bulk power grid without running into major coordinating complexity. Specific proposed approaches to distributed control for smart grids are interpreted.