Читать книгу Smart Grid and Enabling Technologies - Frede Blaabjerg - Страница 36

The future SG is expected to be a flexible and manageable interconnected network consisting of small‐scale and self‐contained sub‐areas, integrated with the large‐scale electric power grid as the backbone. Utilizing micro sources, such as renewable energy sources and combined heat and power plants, into the SG makes them feed their local loads in an economic and environmentally friendly manner [39]. Therefore, the SG control architecture should therefore be dynamic and multilayer to handle real‐time operation and provide tradeoff between performance and implementation. Advanced control uses high‐speed communication infrastructure, distributed intelligent agents, analytical tools, and operational functionalities. The advanced control systems in the SG monitor the essential components, provide timely response, and enables the detection, prediction, disconnection, and self‐healing of faults in the system.

Hierarchical control systems of the SG are distinguished between multilevel systems and multilayer systems. The multilevel system is based on the cooperation of independent controllers which cooperate to control the trading of the power. The multilayer system is based on individual actions with each controller having its own objective. A multitude of different architectures of the SG exists to realize such integrated systems. They are known as “distributed,” “decentralized,” “local,” or “central.” [40]. If an information exchange exists among the independent controllers, the control architecture is assumed to be distributed as shown in Figure 1.12. The system could be fully or partially distributed, and this is reliant on the condition that the information is shared between all controllers or among a subset of controllers. A decentralized control architecture‐independent controller controls distinct subsystems. In particular, no information is exchanged among them as shown in Figure 1.13. The local architecture restricts the control on a single device or a single facility. The input data should be in existence locally, and no external communication exists as shown in Figure 1.14. In the event that a central operation unit manages all other devices in a system and aggregates and processes all the corresponding information, a central operation architecture is the case as presented in Figure 1.15.

Figure 1.12 Distributed operation architecture with two levels.