Smart Grid and Enabling Technologies. Frede BlaabjergЧитать онлайн книгу.
at lower cost. Many of SG technologies are already deployed, whereas others are in the demonstration and planning phases. Lastly, the increasing concerns over the natural disasters and terrorist attacks in many countries have motivated the governments to call for a more resilient grid that is less dependent on centralized power stations. SG solutions respond to those challenges and expectations.
1.4 Smart Grid Definition
The Department of Energy (DOE) defines the SG as “the electricity delivery system, from point of generation to point of consumption, integrated with communications and information technology for enhanced grid operations, customer services, and environmental benefits” [15]. The SG implements electricity, information, and communication infrastructures to generate power more efficiently and reliably, and as cleanly and safely as possible for preserving the environment [16]. The European Technology Platform defined the SGs as “an electricity network that can intelligently integrate the actions of all users connected to it generators, consumers, to efficiently deliver sustainable, economic and secure electricity supply” [17]. From the previous definitions, it is evident that the SG is an electrical grid that entails a variety of smart technologies, operations, and measurements such as smart meters, smart appliances, renewable energy resources, electric vehicle, flexible loads, smart markers, various energy‐efficient programs, and smart end users. The SG includes the benefits of advanced communications and information technologies that provide real‐time information which can intelligently and cost‐effectively integrate the behaviors and actions of all users connected to it, i.e. generators, operators and consumers. This will ensure reliable, efficient, and economically viable solutions for the continuous delivery of clean and affordable energy. One important difference between present grids and the SG is the two‐way exchange of power and information within the grid. The conceptual model of a SG is shown in Figure 1.5 [18]. SG implements innovative products and services along with intelligent monitoring, control, communication, and processing to:
Figure 1.5 The conceptual model of SG framework. Ref [18]. Reproduced with permission from Walter de Gruyter GmbH.
Improve facilitation between the grid elements of all sizes.
Permit customers to play an important role in improving the operation of the system.
Offer customers more information and options to participate in the energy market.
Significantly decrease the environmental impact of electricity generation.
Improve the electric system efficiency, reliability, quality, and security.
Improve service quality and reduce electricity cost.
1.5 Smart Grid Elements
The SG architecture consists of three main systems: power, communication, and information. Proper architecture is necessary to ensure SG functionality. The design and analysis of future SGs require fundamental insight into the impact of power network topology and integrated network control with Big Data utilization. Furthermore, it is essential to have an insight into the complex interaction between the physical layer and cyber layer that includes the supporting communication, information, and computational systems. SG architecture can be represented as a layered structure including the following five main layers as shown in Figure 1.6: System architecture, Distribution Control, Applications, Standards, and Cybersecurity measures.
The grid modernization is expected to make the grid more flexible, accessible, and manageable with interconnected networks consisting of a number of smaller‐sized subsystems integrated with a large number of renewable energy sources. Making the grid more accessible is possible by having grid resources available and considering the access to the loads. The SG serves the needs of multiple stakeholders in the electricity industry. Devices and systems developed individually by different vendors and for different electric utilities are employed by various customers, so they must work together in harmony; these systems must achieve interoperability requirement. The upcoming technology in the SG interoperability framework is the real‐time dynamic control and management systems. The components of SG are the combination of intelligent appliances and equipment that play an important role in the production, delivery, and consumption of electricity. SG elements can be grouped into seven key technology areas [19]. These areas are distributed generation, electric storage system, smart meters, advanced control, integrated communications, sensing and measurement, improved interfaces, and decision support using customer engagement and demand response (DR) as shown in Figure 1.7.
1.5.1 Distributed Generation
DER are defined as small‐scale decentralized power generation sites as shown in Figure 1.8 [20]. The systems with DER are modular, and flexible usually located in the vicinity of the load. DER systems utilize renewable energy sources such as small hydro, biomass, biogas, solar, wind, and geothermal. Such systems can be controlled and coordinated within an SG. Using the distributed generation makes the grid active of bidirectional flow of power [21, 22].
Figure 1.6 SG components.
Figure 1.7 Main key technology areas of smart grid.
Figure 1.8 Distributed energy resources paradigm in smart grid. Ref [20]. Reproduced with permission from IEEE.
DERs can offer potential benefits to the electric grid such as improving energy efficiency, enhancing energy security, and ensuring faster recovery of electricity services. DERs may serve in a single structure connected to an isolated grid, become part of a microgrid, or be connected to the distribution system. Distributed generation can support the delivery of clean, reliable power which supports reducing electricity losses over transmission and distribution lines. The impact of the DERs depends on different factors [23]; such as:
Size and penetration level of the DGs.
Type of the DGs, unit ratings, unit impedance, and used transformers used, etc.
Mode of operation and the interconnection methods with the grid or with the local loads.
On other side, the penetration of DGs increases the complexity of power grids and presents significant stability and control challenges, which may cause greater voltage and frequency deviations and coordinating problems. To overcome these challenges, a coordinated control and managing system must be used to provide the continuity of service, while still meeting customer demands and ensuring the vulnerability of the power system.
1.5.2 Energy Storage
ES is an essential technology for obtaining effective utilization of renewable