Electric power distribution is the final stage in the delivery of electricity. Electricity is carried from the transmission system to individual consumers. Distribution substations connect to the transmission system and lower the transmission voltage to medium voltage ranging between 2 kV and 33 kV with the use of transformers. Primary distribution lines carry this medium voltage power to distribution transformers located near the customer's premises. Distribution transformers again lower the voltage to the utilization voltage used by lighting, industrial equipment and household appliances. Often several customers are supplied from one transformer through secondary distribution lines. Commercial and residential customers are connected to the secondary distribution lines through service drops. Customers demanding a much larger amount of power may be connected directly to the primary distribution level or the subtransmission level.
Distributed generation, also distributed energy, on-site generation (OSG), or district/decentralized energy, is electrical generation and storage performed by a variety of small, grid-connected or distribution system-connected devices referred to as distributed energy resources (DER).
An energy management system (EMS) is a system of computer-aided tools used by operators of electric utility grids to monitor, control, and optimize the performance of the generation or transmission system. Also, it can be used in small scale systems like microgrids.
Energy demand management, also known as demand-side management (DSM) or demand-side response (DSR), is the modification of consumer demand for energy through various methods such as financial incentives and behavioral change through education.
In an electric circuit, instantaneous power is the time rate of flow of energy past a given point of the circuit. In alternating current circuits, energy storage elements such as inductors and capacitors may result in periodic reversals of the direction of energy flow. Its SI unit is the watt.
A microgrid is a local electrical grid with defined electrical boundaries, acting as a single and controllable entity. It is able to operate in grid-connected and in island mode. A 'Stand-alone microgrid' or 'isolated microgrid' only operates off-the-grid and cannot be connected to a wider electric power system.
A phasor measurement unit (PMU) is a device used to estimate the magnitude and phase angle of an electrical phasor quantity in the electricity grid using a common time source for synchronization. Time synchronization is usually provided by GPS or IEEE 1588 Precision Time Protocol, which allows synchronized real-time measurements of multiple remote points on the grid. PMUs are capable of capturing samples from a waveform in quick succession and reconstructing the phasor quantity, made up of an angle measurement and a magnitude measurement. The resulting measurement is known as a synchrophasor. These time synchronized measurements are important because if the grid’s supply and demand are not perfectly matched, frequency imbalances can cause stress on the grid, which is a potential cause for power outages.
Mohammad Reza Iravani is a professor in the Edward S. Rogers Sr. Department of Electrical and Computer Engineering at the University of Toronto. He holds the L. Lau Chair in Electrical and Computer Engineering in same department.
A smart grid is an electrical grid which includes a variety of operation and energy measures including:
A sensor grid integrates wireless sensor networks with grid computing concepts to enable real-time data collection and the sharing of computational and storage resources for sensor data processing and management. It is an enabling technology for building large-scale infrastructures, integrating heterogeneous sensor, data and computational resources deployed over a wide area, to undertake complicated surveillance tasks such as environmental monitoring.
An electrical grid is an interconnected network for electricity delivery from producers to consumers. Electrical grids vary in size and can cover whole countries or continents. It consists of:
A distribution management system (DMS) is a collection of applications designed to monitor and control the electric power distribution networks efficiently and reliably. It acts as a decision support system to assist the control room and field operating personnel with the monitoring and control of the electric distribution system. Improving the reliability and quality of service in terms of reducing power outages, minimizing outage time, maintaining acceptable frequency and voltage levels are the key deliverables of a DMS. Given the complexity of distribution grids, such systems may involve communication and coordination across multiple components. For example, the control of active loads may require a complex chain of communication through different components as described in US patent 11747849B2
Rajit Gadh is a Professor of Mechanical and Aerospace Engineering at the UCLA Henry Samueli School of Engineering and Applied Science and the founding director of the UCLA Smart Grid Energy Research Center (SMERC), the UCLA Wireless Internet for Mobile Enterprise Consortium (WINMEC), and the Connected and Autonomous Electric Vehicles Consortium (CAEV).
A Wireless powerline sensor hangs from an overhead power line and sends measurements to a data collection system. Because the sensor does not contact anything but a single live conductor, no high-voltage isolation is needed. The sensor, installed simply by clamping it around a conductor, powers itself from energy scavenged from electrical or magnetic fields surrounding the conductor being measured. Overhead power line monitoring helps distribution system operators provide reliable service at optimized cost.
The unit commitment problem (UC) in electrical power production is a large family of mathematical optimization problems where the production of a set of electrical generators is coordinated in order to achieve some common target, usually either matching the energy demand at minimum cost or maximizing revenue from electricity production. This is necessary because it is difficult to store electrical energy on a scale comparable with normal consumption; hence, each (substantial) variation in the consumption must be matched by a corresponding variation of the production.
Transactive energy refers to the economic and control techniques used to manage the flow or exchange of energy within an existing electric power system in regards to economic and market based standard values of energy. It is a concept that is used in an effort to improve the efficiency and reliability of the power system, pointing towards a more intelligent and interactive future for the energy industry.
Marcelo Godoy Simões is a Brazilian-American scientist engineer, professor in Electrical Engineering in Flexible and Smart Power Systems, at the University of Vaasa. He was with Colorado School of Mines, in Golden, Colorado, for almost 21 years, where he is a Professor Emeritus. He was elevated to Fellow of the Institute of Electrical and Electronics Engineers (IEEE) for applications of artificial intelligence in control of power electronics systems.
Marco Liserre is a University Professor in electrical engineering currently Head of the Chair of Power Electronics at the University of Kiel in Kiel, Germany. He was named a Fellow of the Institute of Electrical and Electronics Engineers (IEEE) in 2013. He is Deputy Director of Fraunhofer ISIT and Founder of ISIT@CAU, 2022. Prof. Liserre is also honored with the prestigious IEEE PELS R. David Middlebrook Achievement Award for the year 2023.
Commelec is a framework that provides distributed and real-time control of electrical grids by using explicit setpoints for active/reactive power absorptions/injections. It is based on the joint-operation of communication and electricity systems. Commelec has been developed by scientists at École Polytechnique Fédérale de Lausanne, a research institute and university in Lausanne, Switzerland. The Commelec project is part of the SNSF’s National Research Programme “Energy Turnaround”.
An Energy Management System is, in the context of energy conservation, a computer system which is designed specifically for the automated control and monitoring of those electromechanical facilities in a building which yield significant energy consumption such as heating, ventilation and lighting installations. The scope may span from a single building to a group of buildings such as university campuses, office buildings, retail stores networks or factories. Most of these energy management systems also provide facilities for the reading of electricity, gas and water meters. The data obtained from these can then be used to perform self-diagnostic and optimization routines on a frequent basis and to produce trend analysis and annual consumption forecasts.
