Electrical Market Management Considering Power System Constraints in Smart Distribution Grids

Poria Hasanpor Divshali, Bong Choi
2016 Energies  
Rising demand, climate change, growing fuel costs, outdated power system infrastructures, and new power generation technologies have made renewable distribution generators very attractive in recent years. Because of the increasing penetration level of renewable energy sources in addition to the growth of new electrical demand sectors, such as electrical vehicles, the power system may face serious problems and challenges in the near future. A revolutionary new power grid system, called smart
more » ... , has been developed as a solution to these problems. The smart grid, equipped with modern communication and computation infrastructures, can coordinate different parts of the power system to enhance energy efficiency, reliability, and quality, while decreasing the energy cost. Since conventional distribution networks lack smart infrastructures, much research has been recently done in the distribution part of the smart grid, called smart distribution grid (SDG). This paper surveys contemporary literature in SDG from the perspective of the electricity market in addition to power system considerations. For this purpose, this paper reviews current demand side management methods, supply side management methods, and electrical vehicle charging and discharging techniques in SDG and also discusses their drawbacks. We also present future research directions to tackle new and existing challenges in the SDG. Keywords: demand side management (DSM); electrical vehicle (EV); micro-grid (MG); power market; power stability; smart grid (SG); source side management (SSM) Energies 2016, 9, 405 2 of 30 hand, the technical issues, such as stability constraints, limit the penetration of RERs in the power system [7] . In order to overcome this limitation, the microgrid (MG) concept was developed. A MG is defined as a cluster of small generation systems, storage devices, and associated combined heat and power (CHP) loads [8] able to operate in both grid connected and autonomous (islanding) modes to increase power quality and reliability [9] . Controlling, maintaining the stability, especially in the autonomous mode, and implementing demand and resource side management of MGs without communication systems is a very complicated and low efficiency process [10] . As a solution, the smart distribution grid (SDG) concept was proposed. The smart grid (SG) can be defined as an electrical system that uses two-way, cyber-secure communication methods and computational intelligence across an integrated electricity generation, transmission, substations, distribution and consumption to achieve a system that is clean, safe, secure, reliable, resilient, efficient, and sustainable. This description covers the entire spectrum of the electricity energy system from generation to consumption [11] . The concept of SGs in large-scale generators or transmission line is not a new idea and has been evolving and improving for a long time because the components have been under the control of utility companies [12] . Large-scale generators [13] or transmission lines [14, 15] use two-way communication and intelligent computational systems; however, as there are not always smart connections between them and distribution networks (loads), the conventional network could not solve the aforementioned challenges. Since the electrical distribution systems are spread over wide geographical areas with numerous clients including electrical power consumers, DGs, and different kind of energy storage systems (ESSs), implementation of SDG is much more complicated than for other parts of SGs. Integrating many DGs into the SDG, on the one hand, can increase the power generation flexibility, but on the other hand, also can makes the power flow control and maintenance of stability much more complicated [16] . SDG still is in early stages of development and based on the authors' best knowledge, there is no large commercial implementation of a complete SDG to date. Nonetheless, some research centers have designed and installed small size SDGs. For example, the Illinois Institute of Technology (IIT), after facing many power quality problems and outages between 2002 and 2006, decided to change their power system topology. Finally in 2010, by installing two Allison gas-fired turbines, they changed the power system of their campus to a simple SDG. A multi-agent control system gave this SG the ability of real-time reconfiguration and power supply optimization [17] . Santa Clara University (SCU) has been developing its SDG since 2011 by installing smart sub-meters in buildings and energy sources, such as solar, fuel cells, and micro-turbines, in its campus electrical network [18] . West Virginia University (WVU) developed a SDG in a small city called Etown based on six integrated inter-related aspects of community life and economic enterprise: Energy, Environment, Ecology, Electronics, Experimentation, and Education. Researchers in WVU can perform tests in a controlled environment of Etown before integrating it into a larger network [19] . These SDGs are used as power supply systems for real consumers; therefore, they have some limitations for testing new methods. Because of these limitations, some research centers have preferred to build SDG testbeds. As an example of such a SDG testbed, the Consortium for Electric Reliability Technology Solutions (CERTS) formulated CERTS MG in 1998, primarily operated by American Electric Power, as a test facility in Columbus, Ohio [20] . The CERTS MG, which includes a 1 MW fuel cell, 1.2 MW of solar photovoltaic panels, two 1.2 MW diesel generators, a 2 MWh to 4 MWh storage system, a fast static switch, and a power factor correcting capacitor bank, is used for the development of a SG control architecture [21] . With the same idea, researchers at the University of Texas at Arlington (UTA), have installed a 1 MW experimental MG test bed that can be operated either in AC or DC mode and can be connected to or disconnected from the grid. This grid can be used to validate simulated models and permits one to explore conditions such as faults and instabilities that would not be intentionally imposed on an operational MG [22, 23]. European research centers are also actively conducting research on SGs. The total investment in SG projects in Europe was about 3.15 billion EUR until 2014 and Energies 2016, 9, 405 3 of 30 between them 578 projects have implementation sites. However, most of them do not have a SDG with complete components such as smart metering, smart demand management, and smart source management [24] . Pacific Northwest Smart Grid (PNSG) is a large and commercial SG project that began in 2010 and has about 60,000 customers across five US states: Idaho, Montana, Oregon, Washington, and Wyoming. This project is designed to help to validate new SG technologies, quantifying SG costs and benefits, and advancing standards for interoperability and cyber security approaches of SG. In addition to Bonneville Power Administration and eleven utilities, University of Washington and Washington State University are involved in this 178 million USD project [25] . Table 1 summarizes the major global SG implementations. Table 1. Major SG implementations in the world. Owner Locations Properties IIT [17] Campus of Illinois Institute of Technology, Chicago, IL, USA Real-time reconfiguration and optimization of gas turbine. SCU [18] Testbed developing a SDG control architecture including fuel cells, solar photovoltaics, diesel generators, a storage system, a fast static switch, and a power factor correcting capacitor bank. UTA [22,23] University of Texas at Arlington, TX, USA Testbed validating of modeling and simulation results in dynamic and transient condition and can operate in either AC or DC and in connected or autonomous mode. Europe [24] 578 projects across Europe Mostly smaller scale projects investigating the practical usage of smart metering. PNSG [25] Five US states: Idaho, Montana, Oregon, Washington, and Wyoming One of largest SG implementations, which started in 2010 and is still in progress. CSGC [26] Colorado Smart Grid City, Boulder, CO, USA A pilot project proposing different DSM programs allowing exploration of SG tools in a real-world environment and studying people's behavior. Since there is still a long way to go to practically implement SG in distribution systems, much research has been conducted to establish the theoretical requirements of such an implementation. Surveys on many different aspects of SG research have been done in [12, 16, [27] [28] [29] [30] [31] [32] [33] . Cardense et. al. in [12] comprehensively surveyed papers related to SDG in the ISI Web of Science up to 2012, categorized them in different classifications, and investigated the popularity of each class. In [27] the authors reviewed the standardization roadmaps of SG around the world and proposed some recommendations for future work in this area. Fang et al. in [16] reviewed the SG literature up to 2011 using three different categories: the smart infrastructure system, the smart management system, and the smart protection system. The authors of [28] and [29] provided comprehensive surveys on demand response in power systems up to 2008 and 2011, respectively. Su et al. in [30] reviewed electrical vehicles (EVs) in SGs and discussed different kinds of EVs, the standards of chargers, battery technologies, and general issues of energy management system with EVs. As communication plays a principle role in SGs, a large amount of researches has been done in this area. Gungor and Lambert [31] explained different communication networks used in the power system to help researchers better understand the hybrid network architecture in the power system. Akyol et al. [32] prepared a survey report for U.S. Department of Energy and analyzed how, where, and what types of wireless communications are suitable to enhance the security and reliability of the nation's energy infrastructure. Wang et al. [33] provided a good survey on communication architectures in the power system. They also discussed the network implementation issues such as delay, reliability, and security in the power system settings.
doi:10.3390/en9060405 fatcat:jygdsc56cjdfjgtbnyqzb2j4ja