In August 2011, Hurricane Irene tested U.S. utilities all along the East Coast. The storm brought winds and heavy rains to the entire Eastern United States, including PECO's service territory in southeastern Pennsylvania. At PECO, the storm was responsible for more than 500,000 power outages from falling trees, flooding and other storm-related damage, but that is only part of the story.
Hurricane Irene left nearly 7 million customers without power in 14 states. Ranking as one of the Top 5 worst storms in PECO's history, Hurricane Irene brought 10 inches (25 cm) of torrential rains and more than 24 hours of winds gusting up to 75 mph (121 kmph). However, PECO was able to immediately react to the storm damage and restore service to nearly all affected customers in just 72 hours — faster than other neighboring utilities — with full restoration completed in just five days.
PECO's emergency preparedness team quickly recognized the pending hurricane could have a major impact on the distribution system, not unlike Hurricane Isabel, which hit the PECO service territory almost exactly nine years ago. The utility made preparations in advance of the storm, secured and scheduled crews, staged materials and configured the grid to best tolerate outages.
Smart Deployment Payoff
For more than a decade, PECO has taken an aggressive approach to the operations of its distribution grid through widespread applications, automation and smart grid functionality. Several key areas of functionality include a remote sectionalizing and restoration program, the installation of an automatic meter reading (AMR) platform, the integration of the AMR and outage management system (OMS), and the ongoing development of smart data analytics. Each of these systems, individually and combined, have resulted in more efficient operations and storm response.
As Hurricane Irene moved into PECO's service territory, the utility was ready. On Aug. 27, 2011, a Saturday morning, the first cadre of storm responders was on site and waiting. The first sign of trouble started in PECO's service territory in the early afternoon, and the full fury of Irene was in effect by that evening. Heavy rains and high winds blanketed the service territory, which led to several tornado warnings and significant flooding. At the height of the storm, PECO had more than 700 field and office staff working around-the-clock shifts to restore power to all affected customers. By Sunday afternoon, Irene had moved northward and continued to wreak havoc and destruction along her path.
At that point, PECO fully engaged its restoration process. Field crews, including mutual-aid crews, worked feverishly to restore power as PECO's back-office teams assessed the damage, analyzed data and dispatched crews to the next job. In many cases, work was hampered by flooded and blocked roads. The restoration efforts concluded on Thursday, as the final affected customers regained power. Mutual-aid crews began to move northward to assist other utilities in their restoration efforts. The remaining work was to return the distribution grid to its normal configuration and assess the overall storm response.
Reclosers and Sectionalizing
PECO's remote sectionalizing and restoration program helped restore power to more than 120,000 customers during the Hurricane Irene event. These customers otherwise would have experienced sustained outages. The supervisory control and data acquisition (SCADA) and operational logs demonstrated that the sectionalizing and effective rerouting of the power supply from one circuit to another maintained the power flow to customers. This is in contrast to a traditional outage response that requires manual switching and restoration. The automatic switches kept customer interruptions to a simple blink of the lights when the automatic switching occurred.
The recloser installation program was initiated in the mid-1990s. In this program, nearly 100 reclosers typically were installed on the worst-performing reliability circuits and others that would benefit from such technology. Today, more than 1,500 reclosers are in use across the PECO system.
Outage Management System
PECO recognized the value of an OMS decades ago. Like many utilities, PECO developed its own in-house solution that met specific needs and requirements but, ultimately, became difficult to manage, support and enhance as more sophisticated requirements were developed. PECO then moved to an off-the-shelf Intergraph Public Safety OMS that offers state-of-the-art solutions. This system employs several logical techniques to predict outages based on customer calls, SCADA system activity and outage notifications from meters.
Working hand-in-hand with the OMS, PECO developed an outage-response process that optimizes the skill sets of its diverse workforce. Specifically, there are two broad classes of first responders: energy technicians and linemen. Energy technicians are dispatched to work on secondary voltage issues such as service drops and meters, while linemen are dispatched to work on primary events such as transformer failures and wire replacement. This differentiation has created the means for PECO to optimize is response to outage events.
The utility continues to use the OMS today. While PECO has made various improvements and upgrades, the system's ability to offer high performance and usability still stands true.
Automatic Meter Reading
As PECO completed its AMR deployment in early 2003, the utility began to focus on new means to leverage the data the AMR platform produces. PECO is currently fully automated with a first-generation Landis+Gyr/Cellnet fixed radio frequency network AMR system. The first step in this process was to employ the outage notification, power verification and restoration confirmation capabilities of the meters by creating an interface between the AMR platform and OMS, and by developing several new business processes. This integration has proven quite successful in shortening outage-response times on the customer average interruption duration index (CAIDI) and creating the means for more efficient dispatch and storm management.
The first opportunity to use the integrated AMR/OMS application was in 2003 during Hurricane Isabel. During this event, PECO used the outage-verification process to cancel approximately 2,400 single customer events where service either had been restored already or power never was lost. This benefit was valued at more than US$250,000 and was considered to have helped reduce the overall duration of the storm restoration.
During the eight years since this event, PECO has improved on its AMR/OMS integration. Most recently, the application significantly contributed to the Hurricane Irene restoration efforts. In this case, the AMR/OMS application provided the means not only to cancel 2,300 single customer events confirmed to have power, but it also was used to cancel more than 350 primary events that either had been restored previously or were incorrectly predicted as a primary events. Furthermore, the application users were able to escalate nearly 700 jobs from a single customer event to a primary event. The differentiation is significant because each benefit represents the different classes of first responders, energy technicians and linemen.
The overall impact of these results has been valued at nearly $10 million, primarily driven by the estimated two-day reduction in the storm-restoration efforts. This is a dramatic increase over the original benefit projections from 2003.
The various smart solutions PECO implemented have enabled the utility to generate a tremendous amount of data to document and self-assess its actions and responses.
Following a major event such as Hurricane Irene, PECO routinely self-assesses its performance and the event outcome. Data and smart analytics have enhanced this process greatly. For example, the utility uses the outage and restoration messages from the AMR system to validate and confirm the reported restoration times and to ensure accurate reporting on the reliability indices, including system average interruption frequency index (SAIFI) and CAIDI. PECO uses a similar tool daily to ensure all reporting is accurate. To perform much of the analytics work, the utility uses internally developed reports or the DataRaker meter data analysis system.
Other notable metrics PECO has developed include the ability to monitor distribution system transformer loading by using daily usage from each connected meter. Such analysis has identified both overused and underused transformers. The metering data also has been demonstrated to create the means to identify incorrect meter-to-transformer relationships in the distribution system connectivity model. A complete and accurate connectivity model is paramount to successful outage restoration, such as PECO's experience with Hurricane Irene.
These applications and solutions are just a sample of what is yet to come as the present generation of systems is replaced with state-of-the art solutions. PECO is currently in the process of implementing the next generation of technology. The utility is replacing 600,000 AMR meters with advanced metering infrastructure (AMI) meters and the associated systems to manage the data and ensure accurate billing. PECO has selected the Sensus FlexNet system for its AMI platform, along with the Oracle MDMS, Aclara ADM system and DataRaker analytics systems.
Applications include data analytics, a meter data managements system and a meter asset management system. The new meters also will bring new voltage monitoring and reporting capabilities as well as introduce service disconnect switches to PECO. These are expected to have a positive impact on PECO's future storm-restoration efforts.
The introduction of a four-tiered communications platform was designed to deliver reliable high-performance services in the most secure manner. The first tier consists of a SONET-based fiber-optic communications network servicing PECO's major substations and facilities. Tier two is a hybrid of WiMAX wireless broadband communications and traditional microwave communications links. This system operates as an extension of the fiber backbone reaching to facilities where the fiber network was not justified. Tier three is the traditional AMI network, which reaches from the individual meter and distribution automation endpoints to common collection points served by tiers one and two. Finally, tier four represents communication from the AMI meter to inside the customer premise, offering consumption values, price signals and support for automatic control of customer devices.
A new distribution management system and geographic information system will act as a foundation for many future enhancements and programs. New distribution automation solutions, in addition to continuing the distribution recloser installation program, will convert 300 existing reclosers to communicate through the smart grid communications network.
A closed-loop conservation voltage reduction pilot will employ voltage data from AMI meters as an input to the conservation voltage reduction application in the distribution management system. Numerous substation improvements, including phasor measurement unit installations, Internet protocol enablement of the SCADA systems and digital relaying upgrades, will be made at multiple locations.
PECO is actively deploying these state-of-the-art solutions, with many elements already on-line and in service or on the verge of deployment. In most cases, all will be deployed by the first half of 2013. It should be noted that, during the design and construction phases of this project, PECO's management team has challenged the project teams to maintain the current benefit levels and to achieve even greater performance and benefit. The team has accepted this challenge and is actively delivering accordingly.
The Benefits of Smart
PECO's efforts in leveraging and deploying smart technology during the past decade has positively resulted in improved network performance and operability, which translates into fewer and shorter power interruptions and, ultimately, greater customer satisfaction. PECO has learned from each system “test” and will be even more prepared for its next encounter with unpredictable weather.
Glenn A. Pritchard (firstname.lastname@example.org) is the technology lead for PECO's smart grid/smart meter project. He has been with PECO for the past 20 years and is a registered professional engineer in Pennsylvania. He has authored numerous publications and often presents at events across the utility industry. Pritchard is a registered professional engineer.
Hurricane Irene 2011
Sept. 1 - Service is restored to all customers by late evening.
Aug. 28, 12 p.m. - The bulk of the storm has moved northward and is dissipating; it is now a tropical storm. Storm restoration begins in earnest
Aug. 27, 3 p.m. - The first bands of high winds and heavy rains hit PECO. Winds and rains increase throughout the night; flooding and downed trees impede local travel.
Aug. 27 - PECO crews are staged and mutual-assistance crews are on site preparing for a 6 a.m. start on Aug. 28.
Aug. 25-27 - PECO begins storm preparations to battle a potential Category 3 hurricane; materials (poles, wires, hardware, line trucks, etc.) and mutual-assistance crews are secured, along with lodging and meals.
Aug. 21 - Hurricane Irene forms and is predicted to hit the East Coast of the United States.