FCIs reduce fault-locating times and improve reliability metrics, especially the Customer Average Interruption Duration Index (CAIDI).

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2 Intelligent electronic devices (IEDs) are the preferred choice for modernizing the grid. Communication among networks of robust IEDs designed for protection, control, and monitoring (PCM) of the power system creates unmatched performance. Traditional instrumentation and control system devices, such as remote terminal units (RTUs) and programmable logic controllers (PLCs), are designed and manufactured for general purposes, not specifically for power system applications. These generic devices contain little or no default awareness of the functions or components of the power system. They must be customized by the end user, who must create, diagnose, and maintain algorithms and settings for application needs. Even end users who are skilled software developers and familiar with apparatus and application requirements must learn the manufacturerspecialized processing, memory, and reliability parameters of generic instrumentation and control devices. IEDs are smart even before deployment due to the expertise and specialized knowledge used during their development. IEDs used in electric power systems in utility and industrial applications are actually multifunction devices. These IEDs are PCM devices first and foremost, but they also serve as information and automation sources. As these IEDs acquire power system data and then perform additional calculations and logic, they create a specific local database with knowledge about the power system asset with which they are associated. Therefore, in addition to present power system values, these IEDs record information about the health, performance, and history of the overall power system, as well as specific assets, such as transformers, breakers, and other primary equipment. 2

3 Smart distribution solutions make the grid safer and more economical to operate and maintain. SEL Distribution Network Automation (DNA) technology combines fast protection with flexible automation and communication for a customized distribution automation (DA) solution that makes a system safer, more reliable, and more economical. Safer. The SEL DNA system makes power safer with high-speed coordination and new methods, such as Arc Sense technology (AST), to detect more faults than ever before and maintain safe operation of the power system. More reliable. The SEL DNA system makes power more reliable by quickly and automatically reconfiguring the system to isolate the fault and restore power to unfaulted sections. This reduces the impact on customers. Faulted circuit indicators (FCIs) and new fault location software also help speed restoration. More economical. The SEL DNA system makes power more economical by implementing volt/var control to improve voltage levels and optimize power factor. SEL has also developed new technologies, such as Load Sense technology (LST), to determine the type of load on the system for conservation voltage reduction implementation. DNA systems range from distributed intelligent devices and sensors to wide-area centralized controls. These fast and efficient systems automate all parts of the distribution grid, from neighborhoods to distributed generation, and improve efficiency by simplifying conservation voltage reduction schemes. Together, we can shape the future of distribution automation. By investing in an advanced, innovative, and flexible system, the technologies of tomorrow can be integrated without fear of expensive system redesigns. 3

4 FCIs reduce fault-locating times and improve reliability metrics, especially the Customer Average Interruption Duration Index (CAIDI). Adding a wireless interface to a traditional FCI provides information to quickly and accurately pinpoint fault locations and further improves CAIDI while transforming the device into a versatile sensor with added benefits. For example, analysis of outage and surge event history yields improved the Momentary Average Interruption Frequency Index (MAIFI) and more efficient maintenance scheduling. A separate radio network specifically for this purpose provides great value and benefit to the distribution system. However, the utility derives even greater value when the radios support multiple simultaneous connections to collect other field data. 4

5 Data acquisition and processing within smart IEDs create a wealth of asset information, including present state and historical information about the IED, the power system apparatus being managed by the IED, and network communication. This valuable information provides situational awareness through data on the state, performance, health, and history of the apparatus, the power system, and its surroundings. Situational awareness, which is the knowledge of a specific event based on information about past events and the present physical environment, leads to greater productivity of automated applications and personnel. Networked, smart IEDs further increase productivity by automatically collecting and storing power system data. Examples include monthly relay and breaker operation, meter reading, breaker condition, and transformer thermal monitoring reports. During fault operations, the automatic fault location calculations provided to dispatch centers increase productivity. Using enhanced Sequential Events Recorder (SER) reports and extended alarms at control centers improves the analysis of power system disturbances, resulting in better determination of asset conditions and faster service restoration. For example, smart IED networks increase efficiency through better monitoring of transformer loading and temperatures, with the additional information collected from on-site weather stations. The environmental information includes ambient temperature, wind speed and direction, precipitation, and solar radiation. More complete awareness of the transformer situation, such as its history, performance, and true environmental conditions, permits analysis of transformer cooling performance and other asset management. In the end, all departments of the utility, including planning and maintenance, are provided decisionrelevant information from the IED network. 5

6 Valuable information from IEDs in the field provides better decision-making information and greater situational awareness. The different types of data require different methods of processing, storage, and transfer. Therefore, the different categories of IED communications provide unique, complementary, and accumulative value proportional to the cost of the communications infrastructure. Data types include: IED operation and diagnostics Protection quality Control indication Metering Fault information SER event notification Alarms Status Apparatus attributes, operation, and diagnostics Equipment health Load profile Power quality Communications channel performance Unsolicited data notification Weather and environment Settings Product, software, and firmware revisions 6

7 The communication for regional centralized systems via distribution automation controllers (DACs) can be deployed in a star configuration or via looped communication, as illustrated on the slide. Here, the DAC acts as the controller for both the DA and the communications network. The simplified installation example demonstrates a centralized DAC that uses meshed radios and multidrop communication to collect information from all of the relays and recloser controls, in addition to making centralized automation decisions. 7

8 Utilities use a smart DAC in the grid infrastructure to automatically react to a fault and reconfigure the network via IEDs in substations and on pole tops. These work in concert with, or instead of, a traditional control center-based supervisory control and data acquisition (SCADA) system. The DAC system analyzes and detects fault conditions, isolates the affected feeder section, and restores power to unaffected sections to effectively reduce outage times. In this case, the power delivery control system intelligently minimizes outages, duration, and affected customers and then reports the actions taken. 8

9 The DAC functions to detect permanent fault and broken jumper conditions on the distribution network with data communicated from the PCM devices. The DAC acts to isolate the affected section of the feeder and restore power to the unaffected sections from the normal source and from an alternate source, if available. The situational awareness of alternate sources and their margins permit educated decision making and better records. The centralized logic engine performs analysis to detect permanent faults, broken jumpers, loss of substation source, and lockout due to miscoordinated protection devices. During the design phase, the distribution network is broken into zones, specifically feeder sections that can be isolated or energized from one or more sources using fault interrupting or switching devices (i.e., breaker, recloser, load-break switch, and so on). The DAC evaluates system conditions to determine if any unfaulted zones are de-energized. If so, it automatically restores unfaulted zones using alternative sources, if available. In addition, it changes settings groups within the IEDs to better coordinate protection devices in the new network topology. Finally, the DAC restores upstream zones that were de-energized due to miscoordination of the protection devices. Information is provided to perform diagnostics of the power system, PCM network, and underlying communications infrastructure via archived reports, which are stored and forwarded to those that need them. 9

10 Restoration of distribution load is still performed manually at many utilities. Personnel operate switches and other sectionalizers until the faulted line is isolated. Radios or other communications links to a DAC allow it to make decisions and perform close and open operations remotely. PCM relays and/or recloser controls with communications capabilities at each switch location with voltage signals supplied from voltage transformers at each side of the switch are other means of reducing restoration times and directly improving traditional reliability data (System Average Interruption Duration Index [SAIDI], CAIDI). Voltage signals from each side of the switch also permit detection of hot/dead voltage conditions, thereby allowing automatic tripping and restoration of switches, improving speed and reliability. The system carefully supervises restoration from alternative sources based on user-defined conditions, including abnormal circuit configuration, hot-line tags, nonreclose status, supervisory control disabled, or communications failures. Alternate sources are selected based on zone load and the available feeder capacity to avoid cascading problems. 10

11 In peer-to-peer applications, each IED communicates with one or two neighboring IEDs. Each IED creates local information and collects data and additional information from other IEDs to make decisions. The locally created data, as well as those collected from other IEDs via message subscription, are then sent to neighboring IEDs, where the data are again used for localized decision making. More rapid and intelligent sectionalization and isolation of individual faulted phases eliminate outages to customers that would otherwise have experienced power disturbances. The reduction in the number and duration of customer outages improves the results of the System Average Interruption Frequency Index (SAIFI), which is the average number of customer interruptions, and the MAIFI, which is the average number of momentary outages. 11

12 As illustrated on the slide, each IED communicates with two neighboring IEDs via direct messaging, such as MIRRORED BITS communications, or potentially with all other IEDs with multicast messages, such as IEC Generic Object-Oriented Substation Event (GOOSE). Each IED creates information and collects it from others to make decisions. Data resulting from local calculation and message subscription are then sent to neighboring IEDs, where the data are again used for localized decision making. These messages are very small and concise so that they can be created and sent immediately following a disturbance, and they travel fast in order to serve high-speed communications-assisted peer-to-peer applications. However, this makes them too brief to be useful for centralized situational awareness, so other messages such as DNP3 and IEC manufacturing message specification (MMS) are used for that purpose. 12

13 Fiber-optic communication works by IEDs sending and receiving pulses of light through a cable with a transparent core. The speed at which that pulse of light travels is governed by the laws of physics. Einstein determined the speed of light in a vacuum as c, or approximately 186,282 miles per second. However, because the pulses of light are traveling through a piece of glass or plastic, they are slowed down. A good estimate is that light travels through fiber at 124,188 miles per second. Therefore, each mile of a fiber route takes about 8 microseconds. With radios, it typically takes between 16 and 30 milliseconds. Perhaps the greatest advantages of direct fiber links are their availability and reliability, as opposed to the atmospheric affects on radio signals. A tradeoff the other direction is that joining lengths of optical fiber are more complex than joining electric wire or cable. The ends of the fibers must be carefully cleaved and then spliced together, either mechanically or by fusing them with heat. 13

14 Leveraging the technology available today in the latest generation of relays and recloser controls along with fiber-optic communication, utilities are implementing peer-to-peer schemes designed to improve reliability numbers. The PCM recloser control performs immediate pole top measurements, calculations of power flow and status, and the required protection actions, and then it time stamps and records the important information. With the ability to talk to neighbors and learn similar information quickly, these controllers locate faults much more quickly that a centralized system. They do not posses situational awareness, only sectional awareness, but they react much more quickly to isolate faults and restore service. This allows avoidance of some faults and shorter duration of others, which improves SAIDI, CAIDI, SAIFI, and MAIFI. 14

15 The combined data and intelligence created by sharing data among the IEDs create a true awareness of the power system. This unique capability represents one of the most valuable modernization efforts possible. In most utilities, this is the low hanging fruit for return on investment (ROI) because most systems are not taking advantage of these existing features in in-service PCM devices and actually use only a fraction of network capabilities. These DA systems make greater use of smart product characteristics built into the IEDs to create a system capable of making observations and decisions and then taking action. This contrasts with currently available systems that simply provide a snapshot of present values with no opportunity to understand trends in power system activity, system performance, or apparatus degradation. 15

16 The overall fault location system contains the following main components: relays, field devices (such as recloser controllers and FCIs), software to retrieve all information from the devices, detailed feeder models, and distribution fault location software (DFLS). The detailed feeder model can be applied to accommodate the nonhomogeneity of feeders. The impact of fault resistance can be minimized using the reactance method. Fault location accuracy is improved using FCI and recloser control data. 16

17 PCM IEDs widely used in electric power systems are the building blocks of a smarter, more reliable grid. There are numerous ways to deploy communications to use all or some of the technologies within IEDs to create different solutions to meet and exceed reliability goals. Automatic Network Reconfiguration (ANR) and outage notifications enable utilities to provide customers with more reliable service. Additional focus on leveraging smart technologies to better inform customers and reduce overall carbon emissions is another common goal satisfied by these solutions. Perhaps most important is that each installation makes financial sense. The measurable benefits of the applications discussed here have demonstrated a tangible ROI with multiple utilities and have created a wealth of business decision-making information. 17

18 Dramatic improvements in power system automation, especially DA applications, are achieved by bringing communications to underutilized, new, and in-service IEDs. SEL is developing IEDs that create new information and enable control of power system assets, so individuals and systems can monitor substations, capacitor banks, voltage regulators, tap changers, reclosers, and intertie switches. By adding new transducers to strategic points in the network, power quality metering, synchrophasors, fault indication, and system automation are improved and a new era of fault location and ANR becomes available. DA systems are being dramatically improved by the careful application of appropriate communications and the migration of IEDs further out into the distribution circuits that are collocated with power system assets to support wider deployment of synchronous, closedloop automation strategies. 18

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