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3. Business Case
4. NIST Wide Area Situational Awareness Use Cases
7. Next Steps
- See my post Phase Synchronizer for a description of how this technology works.
- There have been five massive blackouts over the past 40 years, three of which have occurred in the past ten years. Many blackouts and brownouts occur due to the slow response times of mechanical switches, a lack of automated analytics, and poor visibility – a “lack of situational awareness” on the part of grid operators.
- Visibility is key to grid stability. Operators need to have actionable intelligence that shows them what is happening in real time so they can respond promptly and appropriately. The introduction of SCADA (supervisory control and data acquisition) systems gave a tremendous boost to visibility into grid operations. For the first time, data from multiple sources could be collected and analyzed.
- Many wind and solar photovoltaic generators do not have inherent inertial response because of the present controls associated with the power electronic interfaces to the grid. As a result, when these new technologies replace conventional generation, the frequency response and modal behavior of the power system will change.There will be a lack of inertia and governor response, different excitation, different locations of renewables which will all make integrated control of high speed system resources even more important.
- America is relying on a centrally planned and controlled infrastructure created largely more than fifty years ago before the age of microprocessors that limits our flexibility and puts us at risk on several critical fronts.
- Wide Area Situational Awareness (WASA) represents the monitoring of the power system across wide geographic areas. These broad area perspectives are necessary to maintain system knowledge and decisions that go beyond conventions of individual companies or even RTO boundaries. The requirements for WASA are architecturally significant from the standpoint of requiring uniformity across traditional systems operation boundaries. Enabling WASA based applications brings forward unique requirements and challenges for the Smart Grid infrastructure.
|Oscillations in transmission can go across hundreds or even a thousand miles. From Canada or Wyoming down to Southern California -- that’s over a thousand miles.”|
- AGC - Automatic Generation Control – Generators automatic respond in real time to control the power output of the electric generators in accordance with the set limits. - A computation based on measured frequency and computed economic dispatch.
Generation equipment under AGC automatically responds to signals from an energy management system computer in real time to adjust power output in response to a change in system frequency, tile-line loading or to a prescribed relation between these quantities. A Generation output is adjusted so as to maintain a target system frequency (usually 60 Hz) AGC Regulates the moment by moment balancing of load and generation. Steady system frequency = good regulation. The AGC system adjusts the output of generators under its control, typically every 4-10 seconds in the western U.S. State of system is continuously assessed with input from SCADA algorithms that determine required control actions.
- Contingency – The unexpected failure or outage of a system component, such as a generator, transmission line, circuit breaker or other electric element. A contingency plan specifies actions to alleviate the impacts of a possible shortage or disruption of energy. The grid is operated using a conservative approach with margin for anticipated contingencies. This helps to maintain a reliable bulk electric system but also limits throughput capacity. Under selected operating scenarios, it may be advantageous to rely on real-time corrective controls following the contingencies instead of providing operating margins in anticipation of the contingencies.
- Contingency Analysis – (aka N-1 analysis) – Contingency analysis simulates the effects of removing equipment and calculates the results using a model of the power system. Makes sure the transmission system gives power users the ability to draw from a diverse set of power plants in different locations and with different operating characteristics. If the transmission system is robust, with a certain amount of redundancy built in, it can withstand the failure of it most critical lines or other components.
- EMS - Energy Management System – A computer control system used by electric utility dispatchers to monitor real-time performance of various elements of an electric system and to control generation and transmission facilities.
- Control Area Operator - An individual or organization responsible for controlling generation to maintain interchange schedule with other control areas and contributing to the frequency regulation of the interconnection. The control area is an electric system that is bounded by interconnection metering and telemetry.
- FERC - The Federal Energy Regulatory Commission - United States federal agency with jurisdiction over interstate electricity sales, wholesale electric rates, hydroelectric licensing, natural gas pricing, and oil pipeline rates. FERC is also responsible for ensuring the reliability of the nation’s high-voltage interstate transmission system.
Not all transmission is subject to FERC jurisdiction. Public power entities such as the Los Angeles Department of Water and Power are not under FERC jurisdiction. Federal agencies also self-govern, so the Bonneville Power Administration, the Western Area Power Administration and the Tennessee Valley Authority all fall outside FERC’s authority. Finally, most of Texas and all of Hawaii and Alaska are outside FERC jurisdiction because they are not connected, or not tightly connected, to the interstate transmission grid.
- Inter-system Interfaces - those interfaces between the boundary of the utility’s transmission, distribution and customer systems and the boundary of another entity’s systems or devices (i.e., between utility grid management system and RTO system)
- ISO - Independent System Operator - An independent entity that controls a power grid to coordinate the generation and transmission of electricity, provide open transmission access to all market participants on a nondiscriminatory basis, and ensure a reliable power supply. Each ISO coordinates controls and monitors the operations of the electrical power system. An ISO is usually not for profit and can advise utilities within its territory on transmission expansion and maintenance, but does not have the responsibility to carry out the functions/ There are currently eight ISOs including Alberta, California, Florida, New England, New York, Ontario, and Texas plus four RTO’s.
- NARUC - National Association of Regulatory Utility Commissioners - The trade association representing the state public utility commissioners who regulate electricity, natural gas, telecommunications, water and transportation throughout the US. These regulatory commissioners are charged with ensuring that the rates charged by regulated utilities are fair, just and reasonable. NARUC’s mission is to serve the public interest by improving the quality and effectiveness of public utility regulation.
- NASPI - North American SynchroPhasor Initiative - Working to advance the application of information and communications systems within the electric power industry. NASPI is a collaborative effort between the DOE, the North American Electric Reliability Corporation, and North American electric utilities, vendors, consultants, federal and private researchers and academics. NASPI activities are funded by DOE and NERC, and by the voluntary efforts of many industry members and experts. Goals:
- Angle/frequency monitoring for enhanced situational awareness
- Post mortem analysis for disturbances or events
- Voltage stability monitoring
- Model validation and benchmarking
- Enhanced state estimation
- Adaptive protection and control algorithms
- Real-time control applications
- NASPInet– A distributed architecture linking the providers of synchrophasor data (publishers) with applications (subscribers) using a publish-and-subscribe middleware and data bus concept.
NASPInet Data Classification architecture is designed for interconnection-wide phasor data sharing. It is intended to support multiple on-line and off-line phasor data
applications. Services classes supported, with quality of service guarantees for each class are:
- Class A – high performance feedback control
- Class B – feed forward control (state estimation)
- Class C – operator visualization
- Class D – event analysis and off-line queries
- Class E – test and research
A non profit company formed by the electric utility industry in 1968 to promote the reliability of the electricity supply in North America. Establishes reliability standards for planning and operations in order to improve the reliability and security of the North American bulk power system. For example, NPCC assisted the three northeast system operators (ISO-New England, New York ISO, PJM) to develop a plan to share reserves. NERC includes ten Regional Reliability Councils
- ECAR – East Central Area Reliability Agreement
- ERCOT – Electric Reliability Council of Texas
- MAAC – Mid-Atlantic Area Council
- MAIN Mid-America Interconnected Network
- MAP – Mid-Continent Area Power Pool
- NPCC – Northeast Power Coordination Council
- SERC – Southeastern Electric Reliability Council
- SPP – Southwest Power Pool
- SWCC – Western Systems Coordinating Council
- ASCC – Alaskan Systems Coordination Council (Affiliate)
Next-generation visualization is on its way. Of particular note is VERDE, a project in development for DOE at the Oak Ridge National Laboratory. VERDE (Visualizing Energy Resources Dynamically on Earth) will provide wide-area grid awareness, integrating real-time sensor data, weather information and grid modeling with geographical information. Potentially, it will be able to explore the state of the grid at the national level and switch within seconds to explore specific details at the street level. It will provide rapid information about blackouts and power quality as well as insights into system operation for utilities. With a platform built on Google Earth, it can also take advantage of content generated by Google Earth’s user community
In 2009, the DOE awarded $54 million to the WECC's Synchrophasor project to improve grid reliability and transmission efficiency as part of the American Recovery and Reinvestment Act of 2009 (ARRA). This regional project involves nine partner entities. Partners will install or replace synchrophasor technology, also known as PMUs, throughout their service territories, network them together, and provide the data in a secured interface to their electric transmission operators, neighboring utilities, and the CAISO. Planned Completion Date: April 2013 Remaining Spend: $42.9M (of which $22M is funded through the DOE grant)
3. Business Case
- Here is an excellent example of the value of WASA. On January 26, 2008, transformation was lost at Bonneville Power Administration’s Big Eddy substation, near the northern terminus of the 3100 MW DC Intertie. Control center operators in the West observed oscillations and, after the power on the DC Intertie was reduced by 500 MW, it appeared that the oscillations had ceased. However, the oscillations had only been reduced by 50 percent, which is below the observable level, by dispatchers using their main tool — the Energy Management Systems in the control centers. However, in the California Independent System Operator’s control room, synchro-phasor data was available and presented to power system dispatchers. They were able to see the reduced, but still present, system oscillations. When the DC Intertie flow was reduced to zero MW, the oscillations stopped. Providing better situational awareness tools to operators of the system will enable them to see power system vulnerabilities much better and prevent such a vulnerability from ever becoming a disturbance or blackout.
- Wide Area Situational Awareness is one the four "Four Priority Functionalities" identified by FERC in their "Smart Grid Policy" adopted in July 2009. The plan provides guidance to inform the development of a smarter grid for the nation’s electric transmission system and prioritizes the development of key standards for interoperability of Smart Grid devices and systems. FERC will ensure that operators of the nation’s bulk power system have the equipment that gives them a complete view of their systems so they can monitor and operate their systems. Smart Grid technology will play a vital role in making this happen.
- Situational awareness of grid behavior is being transformed by wide-area-measurement networks. Only recently have time-synchronized, high quality measurements (from phasor measurement units – PMUs) worked their way into operating rooms of reliability coordinators and balancing authorities.
- The North American Synchro-Phasor Initiative (NASPI), led by NERC and supported by DOE, is advancing the coordination of the deployment of PMUs and the networking of their measurements for wide-area situation awareness and other applications.
- The Energy Independence and Security Act of 2007 (EISA) requires FERC, once sufficient consensus has been achieved through a process coordinated by the NIST, to adopt standards and protocols necessary to ensure smart-grid functionality and interoperability in the interstate transmission of electric power and in regional and wholesale markets.
- NIST has engaged utilities, equipment suppliers, consumers, standards developers and other stakeholders in a participatory public process to identify applicable interoperability standards, gaps in currently available standards and priorities for new standardization activities in Wide Area Situational Awareness. It developed use cases are a method through which to describe applications and the requirements needed to support them.
|An EPRI study team expects utilities to install approximately 1,250 PMUs throughout the grid over the next 20 years at a total cost of $26-39 million.Source: EPRI|
4. NIST Wide Area Situational Awareness Use Cases
- CA - Contingency Analysis - An Energy Management System (EMS) application that analyzes the security of a power system. It calculates, identifies, and prioritizes: current and power flow overloads in equipment, voltage violations at buses, and system stability problems that would occur if contingency events happen in the future.
- Wide Area Control System for Self Healing Grid Application - The Wide area control system functions comprise a set of computing applications for information gathering, modeling, decision-making, and controlling actions.
- Voltage Security - The Voltage Security function is designed to detect severe low voltage conditions based on phasor measurements of Power and Voltage and upon detection, initiate corrective action such as load shed.
- Monitoring Distribution Operations as a Part of WASA - The results of the analysis are aggregated at the demarcation lines between distribution and transmission.
- Voltage, Var, and Watt Control (VVWC) - The application calculates the optimal settings of voltage controller of LTCs, voltage regulators, Distributed Energy Resources, power electronic devices, capacitor statuses, and may enable demand response means for optimizing the operations following current objectives.
- Mitigate, or even prevent, blackouts - According to the DOE Final Report on the August 14, 2003 Blackout in the United States and Canada, use of data from wide-area measurement systems (WAMS), including synchro-phasor measurements, could have mitigated or even avoided the estimated $4.5 billion in losses suffered by over 50 million people in the 2003 blackout of the northeastern U.S. and Canada.
- Ease transmission congestion and bottlenecks
- Reduce transmission congestion costs from increased transmission transfer capability without building additional transmission capacity
- Optimize the transmission system
- Evaluate power system behavior in real-time
- Prepare the power system for withstanding credible combinations of contingencies, prevent wide-area blackouts
- Accommodate fast recovery from emergency state to normal state.
- Reduce load while respecting given voltage tolerance (normal and emergency);
- Reduce or eliminate overload in transmission lines
- Reduce or eliminate voltage violations on transmission lines
- Situational awareness needs to include information from the distribution and customer systems. These systems are becoming more interconnected with two way power flows becoming more common.
- Utilities have generally deployed silo systems Smart Grid is about an enterprise platform. All departments sharing data and analytics. Actionable intelligence needs to be integrated between IT systems and within the business processes.
- WASA creates very large volumes of data which will present challenges in information processing and management. Advanced software and systems will be needed to manage, process, and render this data into a form suitable for human operators and automated control systems. The Institute’s process should strive to identify the core requirements for such software and systems that would be most useful to system operators in addressing transmission congestion and reliability.
- The DOE is providing grants to install more than 850 PMUs. Per the DOE, these PMUs “will cover 100% of the U.S. electric grid and make it possible for grid operators to better monitor grid conditions and prevent minor disturbances in the electrical system from cascading into local or regional power outages or blackouts.
- In October 2009, the Western Electricity Coordinating Council (WECC) was awarded $54 million of Smart Grid Stimulus funds (See my blog Smart Grid Stimulus) to install over 250 phasor measurement units across Western Interconnection and create a communications system to collect data for real-time situational awareness. (Project Scope White Paper PDF) The Smart Grid stimulus is a matching grant program so total project value will be $108 million. The project will improve integrated systems operation across 11 organizations and in all or part of 14 western states, enhancing reliability and reducing energy loss.
- In the same grant, the New York Independent System Operator was awarded $37 million to deploy a range of smart grid technologies, including 35 new phasor measurement units and 19 phasor data concentrators, across NY to allow area-wide control, and an open, flexible, interoperable, secure, and expandable communciations system that will work in concert with the existing control and monitoring systems.
- The Midwest Independent Transmission System Operator was awarded $17 million to install, test, integrate and monitor 150 phasor measurement units in strategic locations across the Midwest on independent transmissions system operators, which will improve the energy dispatching, system reliability and planning capabilities.
- PJM Interconnection was awarded $14 million to deploy over 90 phasor measurement units and other digital monitoring and analysis technologies across 10 states that will provide real-time data on the operating conditions of the transmission system, improving reliability and reducing congestion.
- American Transmission Company was awarded $11 million to build a fiber optics communications network for high-speed communications to maximize the full capability of phasor measurement networks across ATC's transmission system.
- Examples of the types of demonstration projects under this funding opportunity announcement include:
- Reliability Coordinator saturation Demo – Projects to establish an extensive measurement hardware, communications, processing and applications deployment within one of the Reliability Coordinator regions . This could include a new, dedicated fiber network for all bulk power transmission system communications linking the synchrophasor measurement devices with the control center(s) and linking to generation and transmission assets that facilitate phasor and other phasor-related applications.
- Reliability Coordinator Synchrophasor Backbone Demo – Projects to establish a communications network to link standard configuration measurement and data collection hardware to deliver fast data traffic between Reliability Coordinators and major Balancing Authorities within an area. This should serve as the foundation for supporting multiple synchrophasor applications.
- Phasors for Renewable Generator Interconnection –Projects to install a networked phasor measurement unit at every large renewable generator and key substation within a specific area, e.g., within a single Reliability Coordinator’s region. Design and initiate a research project for data analysis to identify impacts of intermittent generation over various time spans. Link to intermittent generator analysts and share data patterns with adjacent Reliability Coordinators to design methods to feed patterns into intermittent generation forecasting and grid analysis. Integrate phasor data into real-time grid monitoring and operations. Look for ways to use the phasor data to feed into new renewable integration opportunities, including ancillary services provided by demand-side resources.
- NASPInet Demo –Following the release of the draft NASPInet specification, expected in mid-2009, there will be pilot demonstration projects to further refine and modify this specification based on lessons learned from interconnecting multiple vendors and a spectrum of applications in a common architectural framework.
- National Grid UK - A leading example of higher economic efficiency through better monitoring and more optimal control of the transmissionsystem is at National Grid in the UK. To prevent grid instabilities, transmission grid operators have historically had to constrain output. This leads to lost revenues and underutilized systems. National Grid is deploying security-constrained scheduling to maximize transmission efficiency by utilizing a networkmodel that enforces thermal security criteria using both pre-contingency and post-contingency controls.12 The use of both types of controls—as opposed to all conventional security constrained scheduling solutions, which only use pre-contingency actions—enables more efficient use of the transmission grid and higher economic efficiencies. This solution will be in operation by the end of 2016, and National Grid expects to save millions of pounds annually in their balancing energy costs as a result.
- NYISO - New York Independent System Operator - One real-world example of where advancements in grid monitoring technology is leading to higher economic efficiencies while maintaining system reliability is at NYISO. NYISO is making tremendous strides in creating a smarter grid that transmits a stable, reliable supply of electricity from an increasingly diverse mix of generation sources. As part of their smart grid initiative (SGIG), they are deploying online voltage stability monitoring that uses PMU technology to optimize transmission use while adapting to dynamic operational conditions spurred by increases in renewable resources and load variability. Resulting optimal utilization of the grid enables higher market efficiency and ultimately lowers electricity cost to the consum
- WECC – Western Electricity Coordinating Council– Situational Awareness
- Patel M, S Aivaliotis, E Ellen, et al. October 2010. NERC Real-Time Application of Synchrophasors for Improving Reliability.
- Novosel D, V Madani, B Bhargavam, V Khoi, and J Cole. January-February 2008. "Dawn of the Grid Synchronization." Power and Energy Magazine, IEEE, vol.6, no.1, pp.49-60.
- Navigant - Synchrophasors and Wide Area Situational Awareness Next-Generation Technologies for Transmission Grid Management and Wide Area Monitoring Systems: Global Market Analysis and Forecasts