by Matt Smith, Silver Spring Networks
Energy drives the lives of billions of people worldwide, and when the power goes off, customers want it back on, and fast. This is especially true in a time of crisis when outage prevention and, in the event of a disruption, restoration are critical.
The current outage approach, however, often poses challenges, including a lack of reliable and timely outage reporting (which relies on customer calls), slow restoration of nested outages, and difficulty pinpointing single customer outages. A manual, less automated approach leads to delays and inaccuracies in detecting and scoping outages, inefficient dispatching of crews, and difficulty in accelerating restoration times.
With real-time insight, the smart grid automates key processes including locating and rerouting power around trouble spots, reducing unnecessary truck rolls and saving costs. Utilities should leverage their own experiences or those of their peers to inject self-healing capabilities that automatically initiate power restoration before the first customer calls. Utilities can achieve the greatest grid reliability through a unified networking platform that allows for data convergence and network convergence. These will help accelerate outage detection and restoration efforts efficiently by connecting switches and metering endpoints on one network.
Smart Grid Tested, Proven During Superstorm Sandy
No matter the time of year, utilities must be prepared for Mother Nature. In the wake of Superstorm Sandy in 2012, utilities, government officials and environmental organizations noted the benefits of smart grid programs, including those that had only partially complete implementations, to accelerate power restoration.
Some 60,000 workers responded to about 9 million customers who lost power. In the immediate aftermath of the disaster, officials including Maryland Gov. Martin O’Malley said the grid is not as strong as it needs to be for the more frequent violent weather patterns. Environmental Defense Fund Director Miriam Horn said smart grid investments proved their value during Sandy in reducing recovery times, keeping crews and customers safer and saving money.
In Washington, D.C., Pepco, with 425,000 networked smart meters, restored power to all its affected customers within 48 hours of the storm using advanced metering infrastructure (AMI) to verify restoration quickly and easily. Then-Energy Secretary Steven Chu praised Pepco’s speed in restoring service.
With just 10 percent of a planned 1.3 million smart meters installed at the time, Baltimore Gas and Electric (BGE) had restored power to 90 percent of affected customers within 48 hours. BGE CEO Kenneth DeFontes said the utility’s ability to restore power in areas that already were using AMI was much faster than in areas without smart meters. With smart meter technology, BGE could target crews to work on remaining outages and not waste time where power had been restored.
Smart Grid Delivers Real-time, Granular Info
During Sandy, utilities credited smart grid technology for improved, streamlined outage management. To be storm-ready in the future, utilities may apply the following five imperatives to any smart grid program for small- or large-scale outage management:
1. Integration between AMI and utility systems. An AMI system must be linked to a utility’s outage management system (OMS) to support two-way communications regarding outages and restorations and deliver last-gasp alarms when power is lost and notifications when service is restored.
2. Timely outage notification. Key to this accuracy is an ability to deliver 100 percent of last gasps for single meter outages and larger outages. An AMI system that delivers last gasps within seconds allows a utility’s OMS to initiate power restoration before the first customer calls and assist dispatchers in assigning repair crews more efficiently and cut restoration times.
3. Intelligent analysis and processing of outage data. By providing utilities with relevant, actionable information, a modernized AMI helps focus and accelerate utility staff response and avoid overwhelming the OMS. Utilities don’t want to open outage tickets and create work orders unless a sustained outage has occurred. Through automatic recognition of nonoutage data such as last gasps from planned meter maintenance or removal, malfunctioning meters and momentary outages, a rapid and intelligent analysis reduces the volume of data sent to the utility and OMS for processing. For example, by correlating individual meter outages to a common transformer, Silver Spring’s AMI easily can spot and report a transformer outage.
4. Immediate verification of power restoration. As many as 75 percent of outage reports are for single service outages, according to smart grid consulting firm Enspiria Solutions. With valuable restoration alerts, utilities can quickly see the status of specific meters and focus crew efforts where needed. In addition, utilities can identify nested outages more easily while crews are still in an affected area.
5. Support two-way communications. An AMI system should support two-way communications with distribution automation devices such as reclosers, feeder switches and capacitor bank controllers that allow utility maintenance crews to locate trouble spots on the network and reroute power around them. Navigant Research estimates that AMI and distribution automation integration is expected to increase from 2 percent of endpoints in 2012 to more than 15 percent in 2020.
A Converged Network Approach: Distribution Automation
Network convergence yields key advantages. The combination of detailed usage and voltage data from the AMI network, along with real-time monitoring and control of the distribution grid, provides new opportunities for grid optimization and efficiency increases. Conservation voltage reduction (CVR), which has been around for decades, can yield double the energy savings by leveraging the power of premise-level voltage monitoring at each meter. Integrating meter alerts and grid monitors with an OMS greatly improves outage restoration.
Distribution automation allows utilities to be more efficient and reliable in the wake of a weather disaster. In the past, crews had to go physically to the site and handle everything manually, which could take hours. Smart grid distribution automation technologies identify and pinpoint outages for utilities, allowing them to isolate and work around problem areas more easily. If a tree goes down and causes a line to fall, distribution automation can redistribute power around the affected pocket—avoiding faults—to ensure nearby customers don’t lose power.
Fundamental to real-time fault isolation is a resilient two-way communications network that enables centralized command and control and low latency peer-to-peer communications for the decentralized coordination of intelligent reclosers and switches.
Next-generation distribution automation enables utilities to gain a real-time understanding of and control over the distribution network. The benefits of next-generation distribution automation are substantial: It can cut the time for system restoration after a fault, improve prediction of equipment failure, boost operational efficiency, and facilitate electricity management. Achieving these benefits requires wide-scale deployment of intelligent distribution devices along with the right network.
Additional benefits can be achieved from convergence. Florida Power & Light Co., for example, leverages a converged AMI and distribution automation approach for outage restoration and prevention. The scope of its Energy Smart Florida program includes distribution devices including reclosers, automated switches, voltage sensors and line monitors, and protection and control appliances. In addition to noting faster outage restoration times in the 2013 storm season, the utility said the program has helped reduce daily outages by 40 percent.
By understanding the communications requirements of distribution automation, utilities can ensure they deploy a smart grid network capable of supporting next-generation distribution automation in conjunction with AMI and other applications. Ideally, utilities should be able to leverage common network components, if not outright common infrastructure, in deploying a diverse set of smart grid applications.
Matt Smith is senior director of utility solutions at Silver Spring Networks.
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