The conventional electric power grid features on a vertical hierarchical up-down design approach consisting of the generation, transmission and the distribution systems. The new forms of markets with diverse consumers, integration and high penetration of renewable energy resources and the distributed generation call for evolutions of the conventional power grid. The next-generation power grid, namely smart grid, is meant to overcome the existing challenges and to improve the quality of the energy service and generation. Enhanced quality, improved controllability, higher reliability and security, demand-side management (DSM), smart appliances and technologies are some motives for the smart grid. Disassembling and reorganising the conventional grid hierarchy, communication, real-time advanced metering infrastructure, grid optimisation and computational intelligence are the main aspects of the smart grid development to achieve the targeted environmental and the economic benefits.

Chapter Contents:

• 9.1 Introduction
• 9.1.1 Voltage profile as power quality index
• 9.1.2 Microgrids
• 9.1.3 Motivation of cooperative decentralised control in smart grid
• 9.2 Decentralised and distributed control systems
• 9.2.1 Contraction-based multi-agent systems
• 9.2.2 Contract net interaction protocol
• 9.3 Centralised hierarchical control of the DERs
• 9.3.1 Frequency regulation
• 9.3.2 Voltage magnitude regulation
• 9.3.2.1 Predefined constant voltage control
• 9.3.2.2 V-Q droop control at the PCC
• 9.3.2.3 Power factor regulation
• 9.4 DER integration concealment
• 9.5 Reactive power dispatch
• 9.5.1 Power-flow equations
• 9.5.2 Sensitivity calculations
• 9.5.3 Modal analysis
• 9.6 Distributed voltage control schemes
• 9.6.1 Optimisation based on the Lagrange multipliers method
• 9.6.2 Distributed voltage control via multi-agent system
• 9.6.2.1 CNIP-based reactive power dispatch
• 9.6.2.2 Distributed multi-agent approach for sensitivity calculation
• 9.6.3 Distributed voltage control with simplified model-based sensitivity calculation
• 9.6.3.1 Simplified model-based sensitivity calculation
• 9.6.3.2 Distributed sensitivity-based reactive power dispatch
• 9.6.3.3 Droop-shaped sensitivity-based reactive power dispatch
• 9.6.4 Decentralised cooperative optimisation using self-organised sensor network
• 9.6.5 Distributed cooperative gradient-descent optimisation of reactive power dispatch
• References
• Further Readings

Inspec keywords: demand side management; power system control; voltage control; smart power grids

Other keywords: economic benefits; grid optimisation; computational intelligence; demand side management; generation systems; electric power grid; decentralised voltage control; smart grids; real-time advanced metering infrastructure; energy generation; energy service; transmission systems; diverse consumers; renewable energy resources; vertical hierarchical up-down design; smart appliances; distributed generation; environmental benefits; next-generation power grid; distribution systems

Subjects: Control of electric power systems; Power system management, operation and economics; Power system control; Voltage control