Shay Bahramirad

State of the Art in Research on Microgrids: A Review

The significant benefits associated with microgrids have led to vast efforts to expand their penetration in electric power systems. Although their deployment is rapidly growing, there are still many challenges to efficiently design, control, and operate microgrids when connected to the grid, and also when in islanded mode, where extensive research activities are underway to tackle these issues. It is necessary to have an across-the-board view of the microgrid integration in power systems. This paper presents a review of issues concerning microgrids and provides an account of research in areas related to microgrids, including distributed generation, microgrid value propositions, applications of power electronics, economic issues, microgrid operation and control, microgrid clusters, and protection and communications issues.

Microgrid Planning Under Uncertainty

This paper presents a model for the microgrid planning problem with uncertain physical and financial information. The microgrid planning problem investigates the economic viability of microgrid deployment and determines the optimal generation mix of distributed energy resources (DERs) for installation. Net metering is considered for exchanging power with the main grid and lowering the cost of unserved energy and DER investments. A robust optimization approach is adopted for considering forecast errors in load, variable renewable generation, and market prices. The microgrid islanding is further treated as a source of uncertainty. The microgrid planning problem is decomposed into an investment master problem and an operation subproblem. The optimal planning decisions determined in the master problem are employed in the subproblem to examine the optimality of the master solution by calculating the worst-case optimal operation under uncertain conditions. Optimality cuts sent to the master problem will govern subsequent iterations. Numerical simulations exhibit the effectiveness of the proposed model and further analyze the sensitivity of microgrid planning results on variety levels of uncertainty.

Building Resilient Integrated Grids: One neighborhood at a time.

The microgrid, as defined by the U.S. Department of Energy, is a group of interconnected loads and distributed energy resources (DERs) with clearly defined electrical boundaries that acts as a single controllable entity with respect to the electric utility grid. DERs consist of distributed generation (DG) and distributed energy storage (DES) installed at utility facilities, e.g., distribution substations, DG sites, or consumer premises. A microgrid must have three distinct characteristics: 1) the electrical boundaries must be clearly defined, 2) there must be control systems in place to dispatch DERs in a coordinated fashion and maintain voltage and frequency within acceptable limits, and 3) the aggregated installed capacity of DERs and controllable loads must be adequate to reliably supply the critical demand. The microgrids may be operated in two modes.

The Interface of Power: Moving Toward Distribution System Operators

The Deployment of a Distribution System Operator (DSO ) is becoming a necessity as a result of the distribution grids increasing roles and functionalities to ensure an efficient and reliable delivery of electricity to emerging proactive customers. The preferences of customers have evolved as they are willing to have more control over their energy use and transactions with the utility grid. In parallel, there is a potential need for an intermediate entity between the independent system operators (ISO s) or regional transmission operators (RTOs) and distributed energy resource (DER) owners due to the limited visibility and control over the meter resources. A DSO may efficiently utilize DERs to improve system reliability and resiliency and reduce emissions and greenhouse gasses by resource diversification.

Is there a place for power quality in the smart grid

This paper contains some thoughts on the relations between power quality and smart grids. It includes some of the, in our opinion, important research and development activities that are needed within power quality as part of the transition to the smart grid.

Optimizing Traffic Signal Settings in Smart Cities

Traffic signals play a critical role in smart cities for mitigating traffic congestions and reducing the emission in metropolitan areas. This paper proposes a bi-level optimization framework to settle the optimal traffic signal setting problem. The upper-level problem determines the traffic signal settings to minimize the drivers’ average travel time, while the lower-level problem aims for achieving the network equilibrium using the settings calculated at the upper level. Genetic algorithm is employed with the integration of microscopic-traffic-simulation-based dynamic traffic assignment (DTA) to decouple the complex bi-level problem into tractable single-level problems, which are solved sequentially. Case studies on a synthetic traffic network and a real-world traffic subnetwork are conducted to examine the effectiveness of the proposed model and relevant solution methods. Additional strategies are provided for the extension of the proposed model and the acceleration of solution process in large-area traffic network applications.

Trusting the Data: ComEd's Journey to Embrace Analytics

The convergence of information technology (IT) with the 20th-century power grid has resulted in the development of smart electricity grids in the 21st century. The ultimate goal in the introduction of IT is to achieve an adaptable, secure, reliable, resilient, and flexible power grid that is able to address current and future reliability, economic, and environmental challenges. The application of IT has also resulted in myriad sensors and measurement and monitoring devices, among others, for enabling real-time, more intelligent control of the electricity infrastructure. Communication sensors often gather much more data than required for their intended applications in power grids. The storage and utilization of such data allows further applications in power grids, ranging from real-time alarm processing of potential grid violations and directing maintenance crews to trouble spots during major storm events to finding seasonal trends in deteriorating power quality levels. The collected data (labeled “big data” in the literature) require efficient storage, processing, and analytics, which is a major challenge for large utilities worldwide. In addition, if the collected data are not accurately analyzed for management decision making in utility companies, the envisioned benefits of the smart grid will not be fully captured and investments will be wasted. The ultimate goal for utilizing a smart grid is to efficiently integrate big data with diverse sets of applications and enhance the operations and control of electricity grids for addressing the energy needs and challenges in an evolving environment.

A Hybrid ac\/dc Nanogrid: The Keating Hall Installation at the Illinois Institute of Technology.

Following the emergence of microgrids, the concept of nanogrids has been proposed for assimilating distributed energy resources in low-voltage applications. In principle, a nanogrid has a similar structure to a microgrid, but it is spread out in a much smaller geographic area (e.g., a single building) and usually entails a much smaller capacity. Nanogrids are designed to satisfy very specific objectives within a microgrid. For instance, the surgery building within a hospital campus or the police station within a university campus could be regarded as critical operations that would be designed as nanogrids. The implementation of nanogrids is also subject to fewer technological challenges than those encountered in microgrids. In accordance with the increasing popularity of solar-plus-storage utilization at a single-building level, nanogrids tend to flourish with time, thereby meeting the goals of smart-grid technology to enhance the economic advantages, sustainability, reliability, and resilience of electric power services supplied to electricity customers. The nanogrid was traditionally designed as a diesel-based, off-grid installation to supply basic loads in remote locations of the world. What is different here is the introduction of an ac/dc technology that utilizes control and communication strategies embedded in smart grids for supplying critical loads in a urban-based microgrid.

Guest Editorial: Special Section on Asset Management in Smart Grid

Electric power system and its components, most of which developed based on the rising electricity demand during economic growth periods of 1970s and 1980s, have aged and some are not being replaced quickly. In addition, the integration of variable sources of energy has changed the way assets are being managed for optimal operation. Aging assets and uncertainty in power system load profile and demand management create a challenge for the optimal operation and maintenance of the electricity grid. This special section aims at addressing the challenges and opportunities in deployment of smart grid technologies such as wireless sensors for condition monitoring and intelligent electronic devices to improve transmission and distribution asset maintenance and repair strategies, asset management in microgrids for enhancing power system sustainability, reliability, and efficiency, and further bring together the state-of-the-art technologies and best practices in asset management in the smart grid era. Through a careful peer review process, 14 papers representing diverse topics on asset management and aging infrastructure are included in this special section. Based on the various aspects of contributions, these papers are categorized into five groups.

Powering the Future: New Initiatives for the Society [Leaders' Corner]

Reports on new initatives, areas of project development, and activities planned for PES society members.