方向继电器必须以适当的电流极性接线（电流变换器 [CT] 和中继终端），从而适当运行以防止故障。极性定义继电器的方向保护元件的正向。在许多应用中，数字继电器的计量功能正被用于替换单独的数据采集与监视控制系统（SCADA）计量设备。本计量的功率流方向（瓦特和VAR）还由CT电路的极性定义。这会带来问题，因为某些数据采集与监视控制系统应用需要计量的功率流方向与保护元件的方向相反。SEL 400系列继电器的自动化算术变量可用于反转这些应用的计量值。
Digital Fault Recording (DFR) systems play an important role in the substation because they capture necessary information in order to understand anomalous behavior in the power system and help utilities isolate failing equipment, locate faults, predict maintenance needs, and much more. This Application Note explains how the powerful processing capabilities of the SEL-3555 Real-Time Automation Controller (RTAC) can be combined with the flexible and modular SEL-2240 Axion® I/O platform to solve the digital fault recording needs in the substation. This combination provides longer event recording durations, scalable digital storage, and faster sampling rates to record large amounts of valuable data that other sources cannot capture.
Installation and operating costs of inverter-based distributed energy resources (DERs) continue to decline. In many cases, these resources are making renewable energy solutions cost-competitive with traditional forms of electric power generation. Photovoltaic (PV) and battery are two inverter-based resources trending toward lower costs. These DERs offer unique technical and economic opportunities to optimize electric power delivery. To take full advantage of these systems and to provide the maximum benefit to owners, operators, and the grid, the inverter-based DERs need accurate and reliable control. SEL developed an off-the-shelf control system that helps owners of renewable energy installations meet interconnection utility and regulatory requirements.
The SEL-849 Motor Management Relay is a versatile product suited for both industrial and utility applications. It offers current-, voltage-, and thermal-based motor protection; current- and voltage-based feeder protection; arc-flash detection; and power metering. The relay provides the option for fail-safe or nonfail-safe tripping mode. Motor applications typically use the nonfail-safe mode, but fail-safe mode may be preferred for other applications. Each output can be set for either mode. This application note will describe these modes and how to use them specifically for the SEL-849.
Many power utilities across North America rely on the predictable and guaranteed performance of analog leased phone lines to run power protection and SCADA circuits. Over the next few years, however, national carriers are planning to discontinue their support for DS0 low-speed, analog-based circuits while continuing to offer DS1 leased services. The SEL ICON® Integrated Communications Optical Network can provide a cost-effective conversion from analog devices to leased DS1 circuits that provide the same latency and reliability as DS0 circuits. This application guide provides application examples for converting analog leased line interfaces to DS1 leased service.
Application Note - The desire to reduce carbon emissions and help reduce dependence on oil has led to an increased demand for alternative energy sources, including solar power. This application note explores the application of faulted circuit indicators (FCIs) in solar photovoltaic plant installations.
The desire to reduce carbon emissions has led to an increased demand for alternative energy sources such as wind power. This application note explores the application of faulted circuit indicators (FCIs) to wind farm installations.
This application note describes SEL recommendations for wiring I/O in the euro-style connectors on SEL-2400, SEL-2200, and SEL-700 series devices.
This application note explains how to inject the proper phase-to-phase voltages to test a relay that is connected to an open-delta PT.
This application note discusses basic guidelines for the creation and use of RTAC programming variables and tags and the initialization of each type.
The purpose of this application note is to provide a solution for achieving detailed monitoring of an SEL-2488 Satellite Synchronized Network Clock via Simple Network Management Protocol v2c or v3, over any SCADA system.
The purpose of this application note is to describe how an SEL-3355 Rack-Mount Rugged Computer can be monitored via Simple Network Management Protocol. Instructions on how to configure the SEL-3355 for monitoring via SNMP are given within.
This application note provides a high-level planning guide for converting an SEL ICON Integrated Communications Optical Network from a single-user account to role-based, multiple-user accounts. This conversion requires cooperation and coordination with multiple departments.
This application note explains the types of solid-state drives (SSDs) offered by SEL and assists you in determining the best types of SSDs to use for your applications. To do so, enter data from your application into the digital calculator included in this PDF, click the Calculate button, and consult the results fields.
This application note reviews the COMTRADE export functionality of the Analytic Assistant and synchroWAVe Event 2015 software.
This application note describes how external wetting power supplies in SEL devices provide the most flexible and robust solution for monitoring contacts.
This application note explains how to use network address translation (NAT) to add a redundant connection to a dynamic routing network where SEL-5051 Network Management System Software and the ICON® are on different subnets.
This application note describes the differences between Lightweight Directory Access Protocol (LDAP) and Remote Authentication Dial-In User Service (RADIUS) protocol and how to select the correct protocol for centralized authentication. It also discusses security considerations for implementation.
This application note shows how to use the SEL-2488 Satellite-Synchronized Network Clock as a grandmaster with multiple connections to a redundant network topology.
This application note shows how to use the SEL-2488 Satellite-Synchronized Network Clock to provide highly accurate time to isolated networks without compromising design requirements or connecting the networks.
El documento anexo permitirá configurar variables analógicos como eventos en el Registrador Secuencial de Eventos (SER) y posicionarlos en la base de datos del controlador de automatización en tiempo real (RTAC).
This application note discusses how the SEL System Control (SSC) library can be used to add features, such as watchdog protection, directly to customer applications and how to add basic system monitoring to operating systems without SEL SysMon support.
This application note explains two possible acSELerator Team® configurations for solving time-stamp issues and outlines the strengths and weaknesses of each.
This application note describes the control functions in the SEL-2411 Programmable Automation Controller that can be used in a duplex lift station with primary SCADA control and a failover to local automatic or manual control.
This application note discusses how to use a read-only domain controller on an SEL rugged computer for user authentication during a wide-area network link failure.
This application note provides the calculations to determine system availability or how infrequently the functionality of the SEL ICON® Integrated Communications Optical Network System is impacted by a fault or defect.
This application note discusses how to prevent unnecessary blinks of power by enabling the second-harmonic blocking feature in the SEL-351RS Kestrel® Single-Phase Recloser Control, SEL-651R Advanced Recloser Control, and SEL-351 Protection System family.
This application note describes how to protect against breaker failure using the SEL-487B Bus Differential and Breaker Failure Relay.
Application Note - This application note describes an SEL solution to synchronize intelligent electronic devices that do not support the IRIG-B signal but do support time synchronization via serial communication and periodic ASCII time synchronization message broadcasting.
This application note explains the operation and benefits of applying Overhead AutoRANGER® faulted circuit indicators on lightly loaded circuits.
This application note provides a protection scheme that solves the problem of misoperation due to simultaneous faults on distribution systems.
Application Note - This application note describes an SEL solution for creating a SCADA server or gateway to interface substation equipment and apparatus with a SCADA master station.
Application Note - Using temperature measurement sensors with SEL relays provides a very powerful method for detecting system health in substation equipment. While many SEL relays provide built-in logic to alarm and trip on a temperature measurement, the raw resistance temperature detector (RTD) values can also be used directly in SELogic® control equations to provide more complex control. Caution must be applied when using RTD values in SELogic control equations, however, as RTD faults can cause misoperations if not handled correctly. This application note provides solutions to prevent misoperations when using the raw RTD values in SELogic control equations.
Date Code 20131113 SEL Application Note 2013-01 Application Note AN2013-01 Applying VLANs With the SEL-2730M to Improve Network Manageability Simon Loo INTRODUCTION A wide-area network (WAN) or local-area network (LAN) is designed to transport data among geographically distributed sites. Networks carry large amounts of
In the past, automatic generator transfer, arc-flash protection, and load-shedding features required separate devices. The system integrator or engineer designed a complex and expensive system to handle all of these functions. These additional devices increased installation costs, maintenance requirements, and the number of components that could fail, possibly derailing the benefits of the system. The SEL-751 Feeder Protection Relay incorporates all of those needed features into one single device.
Application Note - With new drilling and production technologies, the latest oil and gas boom in the United States has led to a rush to drill more and more wells located in vast fields, often in remote areas. Geologic formations, where the oil and gas are located, dictate that the wells are clustered together in pockets that may be isolated from one another. These wells are expected to produce far into the future and, depending on the formation, may eventually require supplementary energy to continue oil and gas flow to the surface as the well matures to sustain production. Once the wellbore pressure (ρw) is greater than the formation pressure (ρf), a secondary energy source is necessary to continue the flow of oil and gas to the surface.
Application Note - The T1 or DS1 interface is a standard telecommunications interface that is widely used to transport voice and data circuits between network equipment. This application note describes the DS1 interface and DS0 grooming capabilities of the SEL ICON™ synchronous optical network (SONET) multiplexer and shows application examples of how the ICON can interoperate with T1 multiplexer equipment to transport voice and data circuits.
Date Code 20131023 SEL Application Note 2013-09 Application Note AN2013-09 MCC Arc-Flash Protection Using the SEL-849 Motor Management Relay Via IEC 61850 Alan Saldivar INTRODUCTION Electrical rotary machinery poses several safety risks to workers in various industries. In lowvoltage motor control centers (MCCs), arc-f
Application Note - The interconnected ICON node is provisioned to pass through the SONET payload from the existing network. The ICON inserts its payload into preselected unused bandwidth in the existing network. The existing network passes the ICON traffic transparently as well.
Application Note: In industrial and commercial facilities, users need to interact with process and control equipment locally as well as remotely. Supervisory control and data acquisition (SCADA) systems provide
remote system control. A touchscreen human-machine interface (HMI) provides local user control and system monitoring. HMI screens also provide processed data in tabular, graphical, or animated format locally on the site. This application note describes the use of Modbus protocols to interface different SEL devices with third-party HMI touchscreens.
The SEL-849 Motor Management Relay is a powerful, cost-effective relay used to protect and control motor and feeder circuits. The SEL-849 is suited for new applications and retrofit installations due to its compact size, pass-through current transformer (CT) arrangement, and built-in arc-flash sensor technology. Figure 1 shows an example of a motor control scheme with an SEL-849.
Application Note - This application note explains the value and benefit of inexpensive and robust dual-ring communications among remote sites via SEL Hop-Sync technology in the SEL-3031. Pairs of SEL-3031 radios located at each site and connected via SEL Hop-Sync technology provide continuous peer-to-peer communications simultaneously in both directions around the ring.
Date Code 20130612 SEL Application Note 2013-21 Application Note AN2013-21 Applying SEL-3031 Hop-Sync™ Technology to Distribution Automation Schemes With Collocated Radios Eric Sagen INTRODUCTION Distribution automation (DA) systems have been in use for over a decade. Very few DA systems employ sophisticated communicat
Application Note - Military facilities are upgrading their electrical infrastructure to support the increasing electrical demand of military bases. The size of bases has increased with the addition of more facilities and on-base housing. Military bases are considered a self-contained city needing a complete electrical infrastructure. There are many locations within the base that are considered critical in operation, and they can no longer afford to be out of power for any length of time.
Application Note - The standard SEL-710 Motor Protection Relay thermal model uses a constant rotor resistance during motor starting, which may overestimate the heat building up in the motor during starting. The SEL-710 slip-dependent thermal model is an improvement over the standard thermal model because it takes into account that the actual rotor resistance is being reduced as the motor slip improves during the starting sequence.
Application Note - This application note discusses how the SEL-849 Motor Management Relay, shown in Figure 1, enhances VFD protection and provides redundant backup control for VFD normal operation, malfunction, soft start bypass, maintenance, or replacement.
Application Note - SEL-700 series relays provide protection and control solutions for motors, feeders, transformers, and generators in small, economic packages. The relays share a common user interface, as shown in Figure 1, and can be customized via the programmable liquid crystal display (LCD) screen, pushbuttons, light-emitting diodes (LEDs), and labels.
Fault Data Recorder and Power Quality Monitor for Oil Field Wellhead and Tank Battery Installations
A distributed generator is defined as an energy source that is connected directly to the distribution network. Distributed energy sources include both distributed generators and energy storage devices. Recently, renewable energy sources have been developed, such as solar, wind, and biofuels. Because of the scale of these sources, there is a tendency towards their integration at the distribution level. Distributed generation (DG) is gaining momentum, with governments all over the world pushing towards clean energy and carbon footprint reduction, causing a paradigm shift in the conventional generation, transmission, and distribution of electrical energy. The low installation cost of using SEL-3031 Serial Radio Transceivers allows DG users to comply with regulatory standards and better meet cost targets.
This application note describes security features built into the ICON and the testing performed to ensure security robustness. Protection against unwanted or unauthorized system access is only one part of a complete solution. It is equally important for equipment to send alarms and keep records to increase situational awareness when events occur.
Facilities managers and engineers need accurate, reliable water and energy consumption data systems that are similar to the system shown in Figure 1. They use the data to monitor operating expenses, track energy usage, conserve resources, perform maintenance applications, and conform to regulatory requirements. This application note outlines some of the possibilities of how an SEL-2411 Programmable Automation Controller can be implemented to provide this information.
Advantages of Using Ethernet Pipes to Segregate Networks
Application Note - Using the SEL-735 to Display Multiple Metering Values
This application note identifies how harmonic detection elements in the SEL-351 and SEL-351S Protection Systems can be used to modify relay settings and improve feeder protection security during the energization of transformers.
This application note describes the SEL Network Global Variable List (NGVL) communications protocol and how it can be used within a decentralized control application to share data between processes.
There are different methods for performing current injection testing for recloser controls. A protective relay test set can be used. However, many small municipal and cooperative utilities find the cost and necessary training to use these devices prohibitive. A recloser control tester presents a more economical solution, but the available models are typically designed only for 14-pin controls.
Application Note - Arc-flash detection in certain SEL devices is triggered by the relay sensing light and overcurrent simultaneously. The relay then trips at high speed. When commissioning arc-flash detection systems, testing the overcurrent thresholds is not enough—the light sensors must be tested as well.
The SEL-3031 Serial Radio Transceiver is a 915 MHz ISM serial data radio that supports pointto-point (P2P) and point-to-multipoint (P2MP) operational modes.
Whether dealing with a standardized or proprietary SCADA protocol, the need has always arisen for some form of in-line debugging capabilities that offer a programmer or commissioning engineer a look into the protocol data stream between the SCADA system and the end device. For newer Ethernet connections, a solution is an available class of computer software known as Ethernet packet capture utilities (Wireshark® is an example), but a different solution is needed for serial data streams. The actual device that offers this capability for serial channels is referred to as a serial data line analyzer, and this application note outlines both a traditional and a modern solution for this type of device.
Application Note - This application note provides implementation details and requirements for using the SEL-2401, SEL-2404, or SEL-2407 Satellite-Synchronized Clock with Linux NTP service to create a Linux NTP Stratum 1 server suitable for LAN/WAN (local-area network/wide-area network) applications.
Application Note - Within an electrical utility, several departments must interact with recloser controls. Engineers commonly develop settings and analyze event reports, technicians load settings and retrieve reports, and linemen interface with the front panel to restore power.
Application Note - This application note covers the data acquisition feature of the SEL-2411 Programmable Automation Controller and the programming capabilities of the SEL-3505 Automation Gateway, including its ability to run control algorithms. This application note also discusses using the SEL-3031 Serial Radio Transceiver to communicate between the various remote sites and the server.
Application Note - Using the Wireless Interface in junction enclosures and inside the switchgear of a wind turbine tower reduces the risk of arc flash by avoiding unnecessary opening of high-voltage cabinets. Personnel can easily check the state of fault indicators installed inside the switchgear and junction enclosure with the easy-to-use wireless RadioRANGER Remote Fault Reader.
Application Note - Physical surveillance is a critical part of any physical security program. With the increased awareness of cyberterrorism, the focus for securing a control network has shifted from physical security solutions to electronic security solutions. Both physical and electronic security perimeters are critical to the overall protection of the control network. The North American Electric Reliability Corporation (NERC) physical security standard (CIP-006-1) outlines the minimum set of required controls to physically protect critical cyberassets. The required controls include physical access controls, monitoring, logging, and log retention.
One of the many advantages of SEL protective relays is their automatic self-testing capability. SEL relays include automated self-testing to determine the health of the device. Self-test mechanisms measure and verify that power supply voltages are within range, validate checksums of data, check the ability to read and write to memory, ensure that analog-to-digital conversion is correct, and monitor watchdog timers. A watchdog timer is normally designed to time out when a critical process, like protection, does not complete in its allocated time. For example, if a relay has a 4-millisecond processing interval, the watchdog timer might be designed to expire in 5 milliseconds. Thus a processor stall or other failure is rapidly detected and alarmed immediately.
Application Note - Prolonged exposure to certain concentrations of chemical compounds can cause damage to surface mount technology (SMT) electronic components, resulting in possible failure of power protection, automation, communications, or metering equipment. This application note describes this problem in more depth, identifies some of the industry sectors where these compounds are present, and provides solutions to mitigate their effects.
Application Note - This application note covers the data acquisition features of the SEL-2411 Programmable Automation Controller (PAC) and the SEL-2440 Discrete Programmable Automation Controller (DPAC), including event buffer, event report, and Sequential Events Recorder (SER).
Application Note - Intelligent transportation systems (ITS) with traffic monitoring and managing have become more important as traffic congestion increases on highways and bridges as well as in tunnels, parking lots, and cities. Transportation authorities make appropriate changes to traffic flow, notify public safety personnel, and make traffic condition reports available to the public through the media or direct communication to minimize traffic congestion and increase traffic safety.
Application Note - The SEL tough industrial computers with Windows Embedded Standard 2009 are designed for the types of applications that are needed in utility and industrial environments. SEL tough industrial computers with Windows have been performing reliably all over the world.
Application Note - This application note provides a process on forwarding a copy of Windows® event log data from the SEL System Computing Platform with Windows XP Professional to a central location using
the IETF RFC 3164 syslog format.
Application Note - This application note provides implementation details and requirements for using the SEL-2401, SEL-2404, or SEL-2407® Satellite-Synchronized Clock with the SEL-3332 Intelligent Server or SEL-3351 System Computing Platform With Windows® XP Professional to provide NTP.
Application Note - This application note provides information on how Simple Network Management Protocol Version 3 (SNMPv3) operates securely over a network connection. SNMPv3 over Ethernet or USB operates differently from traditional command line or web-based interfaces. This application note explains the secure flow of data between the network management software and the ICON. The ICON does not support command line or Hypertext Transfer Protocol (HTTP) web interface.
Application Note - This application note describes how enabling and tuning the network firewall can help prevent unauthorized access to a Linux-based operating system. Linux uses iptables as the basis for configuring its firewall. Iptables has been integrated into the Linux kernel since Version 2.4 (the year 2000).
Application Note - This application note guides the reader to the National Institute of Standards and Technology (NIST) Special Publication 1058, which contains information on the impact of antivirus software on control system equipment. This application note is intended to aid asset owners in antivirus decisions to minimize impact on critical processes.
Application Note - This application note presents SEL logic devices, such as the SEL-2411 Programmable Automation Controller (PAC), SEL-2440 Discrete Programmable Automation Controller (DPAC), and SEL-3530 Real-Time Automation Controller (RTAC), as distributed control system solutions for one of the most fundamental sectors in the electrical generation industry—steam control.
Application Note - The SEL-3401 Digital Clock Display is more advanced than many clocks on the market. It can receive an IRIG-B time signal from any appropriate source, including a satellite-synchronized clock. SEL offers a range of satellite-synchronized clocks for use with the SEL-3401, providing an accuracy of ±100 nanoseconds. The following sections explain three different examples of providing synchronized clock systems using the SEL-3401.
Application Note - This application note explains how to use the SEL-3530 Real-Time Automation Controller (RTAC) and SEL-3031 Serial Radio Transceiver to provide faster pilot protection and a backup SCADA communications link.
The programming features in SEL relays, including SELogic® Boolean expressions with math variables and comparisons, provide the capability for custom applications such as the implementation of KYZ contacts.
Application Note - Many subtransmission-level power systems use three-phase on-load tap changer (OLTC) transformers and shunt capacitor banks (SCBs) to provide voltage regulation and VAR support.
Application Note -This application note demonstrates how SEL products provide the means to monitor alarm sensors and send out intelligent alarm notification as an email or a phone call, even acting as a low-cost backup system for activating redundant sirens or strobe lights.
Application Note - The heart of the kiosk is the computer. A reliable computer is needed to withstand the temperature changes and vibrations that may occur where the kiosk is located. SEL tough computers are designed to meet the requirements of kiosk computers.
Application Note - A human-machine interface (HMI) allows an operator to monitor and control the machines used in an automated process. Computer-based HMIs are found extensively in today’s process control systems, using graphical onscreen controls that are virtual representations of the physical switches, pushbuttons, and gauges in control panels of the past. These HMIs range from simple numerical data displays, to basic two-dimensional drawings, to complex three-dimensional renderings of the systems they control. They can trend and archive data, automate control, and advise operators when actions need to be taken.
Application Note - Asset optimization tools are conveniently built into many SEL relays and monitoring devices, eliminating the need for extraneous devices. The SEL-487E Transformer Protection Relay has monitoring capabilities to optimize asset performance and reduce maintenance costs.
Application Note - This application note discusses the features of the SEL-2411 Programmable Automation Controller (PAC) and SEL-2440 Discrete Programmable Automation Controller (DPAC) and the benefits of using this hardware for ingredient dispensing, blending, and mixing applications.
This application note covers features of the SEL-2411 Programmable Automation Controller (PAC) and SEL-3530 Real-Time Automation Controller (RTAC) and the benefits of using this hardware for PV (photovoltaic) solar panel or concentrated solar power (CSP) tracking applications.
Utilities can integrate synchrophasors into existing SCADA/EMS (supervisory control and data acquisition/energy management systems). This integration improves the accuracy and coherency of SCADA systems and allows system-wide application of synchrophasor data. An example would be using synchrophasor data as an input into state estimators to improve estimation results.
Application Note - Network Time Protocol (NTP) is a common protocol used for Ethernet time synchronization in applications requiring 1- to 50-millisecond time accuracy, such as IT (information technology), SCADA (supervisory control and data acquisition), and public safety networks. This application note provides implementation details and requirements for using the SEL-2401, SEL-2404, or SEL-2407 Satellite-Synchronized Clock with the SEL-3530 Real-Time Automation Controller (RTAC) to provide NTP to connected devices.
Application Note - Protective relays and other associated devices can have their onboard clocks and calendars synchronized by an Inter-Range Instrumentation Group (IRIG) time-synchronization signal. The basic demodulated IRIG-B signal accepted by virtually all SEL products (IRIG-B002) includes the time of the day and the day of the year. If the receiving device employs a calendar that reports the full month, day, and year, it must have a provision for entering and storing the year, which is not transmitted with the basic IRIG-B002 signal.
Application Note - This application note demonstrates how the SEL-3620 Ethernet Security Gateway significantly reduces the installation time to protect site-to-site Ethernet communications links from unauthorized access.
Application Note - This application note illustrates how synchrophasors can be used to analyze the effects of remote wind generation on major population centers by monitoring the phase angles reported by the synchronized phasor measurement units (PMUs) monitoring each location.
Application Note -Interconnections are conventionally established to provide reliable power to customers. When local system islanding occurs, the proposed scheme initiates the load-shedding process based on the intertie power exchange and the amount of local power generation to maintain power system stability.
Application Note - The SEL-3378 Synchrophasor Vector Processor (SVP) provides a platform to perform mathematical operations on incoming phasor data using built-in functional blocks and userdefined logic to build custom applications. In order to monitor and archive the calculated or derived data, the SVP provides a programmable virtual phasor measurement unit (PMU). This application note highlights the built-in functions and virtual PMU capabilities.
Application Note - The idea of small, widely distributed power generation has been talked about and implemented on a limited scale since the 1970s energy crisis. Since then, advances in technology and reliability have contributed to the large number of wind turbines installed in the last few years. Looking into the future, carbon limits, government incentives, and the decreasing cost of wind turbine technology will all contribute to the increased installation of distributed wind energy systems. The SEL-547 Distributed Generator Interconnection Relay is a key system component that allows wind turbines to be connected to the electric utility grid. Since its introduction in 2002, the SEL-547 has been installed in hundreds of wind energy installations all over North America.
Application Note - This application note demonstrates how the SEL-2440 Discrete Programmable Automation Controller (DPAC) can enhance the security monitoring and protection of your substation.
Application Note - Islanding detection is important for protecting personnel, preventing equipment damage, and providing good power quality in power systems with distributed generation (DG). This application note discusses islanding detection systems based on wide-area, time-synchronized measurements.
Application Note - In processing plants, line production rates are carefully studied. The outcome of a process equipment area in a production line needs to be balanced with the rest of the system. When there is an unexpected downstream equipment delay, an online accumulation system can avoid starting and stopping critical processes involved in continuous production operations, thus increasing product quality and consistency and maximizing line efficiency.
Application Note - Protective relays sense electrical information and issue trip commands to protect electrical lines and apparatus. Microprocessor-based protective relays perform self-diagnostics. If power to the relay is lost, or if diagnostics fail, the alarm contact will close.
Application Note - Utilities around the world specify SEL for the point of common connection because SEL has extensive experience working with wind generators and complete wind farm applications. Protection and control of wind energy have special considerations for protecting both the wind turbine and the utility connection.
Application Note - This application note highlights some of the benefits of the SEL-2411 Programmable Automation Controller (PAC) when used as an independent control and monitoring system for primary and secondary lubrication pumps.
Application Note - Water storage reservoirs provide customers with uninterrupted service without the need for continuous pumping. Electrical rates in certain regions of the country are structured to discourage use during certain times of the day, making the time of pump operation an important economic factor in the control of pumping systems. The SEL-2411 Programmable Automation Controller (PAC) uses historical and predictive calculations to optimize pumping cycles, thereby shifting water pumping from on-peak electrical rate structures to lower-priced tier periods.
Application Note - This application note outlines some of the benefits of using the SEL-2411 Programmable Automation Controller (PAC) to monitor remote buildings.
Application Note - This application note outlines the versatility and benefits of the SEL-2411 Programmable Automation Controller (PAC) in wastewater lagoon aerator control, monitoring, and protection.
Application Note - Manufacturers commonly employ rotary assembly tables to automate progressive assembly lines and save production floor space. Using SEL automation and communications products will simplify integration of assembly equipment from various original equipment manufacturers (OEMs) and provide reliable system performance.
Application Note - Technology is changing at a rapid pace, and intelligent electronic devices (IEDs) are smarter, faster, and include features only imagined a year ago. How do you make sure you are not missing a significant cost-saving technology? How can you be sure the system you install will meet your needs well into the future?
Application Note - In the 1970s, traffic control systems started to become intelligent . Today, many United States traffic intersections already have roadside cabinets based on the National Electrical Manufacturers Association (NEMA) TS2 and Intelligent Transportation Systems (ITS) standards.
Application Note - This application note discusses valuable features of the SEL-2411 Programmable Automation Controller (PAC) when used to control industrial crushers, grinders, shredders, and chippers. A single SEL-2411 PAC allows for powerful, reliable, and economical machine control.
Application Note -The use of traditional relay-to-relay communications is limited due to the nontime-correlated nature of the information sent between the relays. Using the real-time control capability in certain SEL relays to time-align data between two relays adds an entire new family of applications to protective relays.
Application Note - This application note provides implementation details and requirements for converting an EIA-485 port to the IEEE C37.94 standard through an EIA-422 interface using the SEL-3094 Interface Converter.
Application Note - The SEL-2523 Annunciator Panel provides complete alarming, notification, reporting, and communication of station alarms.
Application Note - With growing public concern about climate change and energy independence, there is an everincreasing desire to add distributed generation (DG) to the existing distribution grid. DG can come in many forms, including wind turbines, photovoltaic, methane capture, and more conventional sources like small gas or diesel generators. All of these new sources help support the ever-growing demand for power.
Application Note -Voltage reduction is a scheme used to reduce the demand on a power system through the intentional lowering of the system voltage. Lowering the system voltage achieves short-term energy savings. Recent studies have found that lowering system voltage by 1 percent will result in approximately 0.5 percent reduction in demand. Because many residential and commercial motors are designed to run at 230 V and 460 V and utilities often provide 240 V through 250 V and 480 V through 500 V, these motors run more efficiently at a slightly lower voltage. However, the savings are greatly dependent on the system load, because lowering the system voltage will affect mainly the resistive portion of the load. Maintaining optimal system voltage is a key component in making the grid work as efficiently as possible and may lead to a reduction in peak load on some systems.
Traditional distribution feeders have been equipped with three-phase fault interrupters. This is particularly true on heavily loaded feeders where unbalance may be a problem. Utilities have had to accept the fact that as many as two-thirds of customers could be affected unnecessarily by a single-phase fault. Many utilities have been reluctant to consider single-phase tripping on the main three-phase line for a number of reasons, including a desire to protect three-phase loads, difficulty coordinating devices along the feeder, and a loss of sensitivity of the protective device for low-magnitude faults. By taking advantage of today’s microprocessor-based recloser controls and the versatile reclosers available, solutions to these problems can be found.
Time-synchronized phasors enable a new perspective into the power grid. They provide a direct view of the power system state and a means to display this information to the power system operators. You can observe quantities such as phase, magnitude, frequency, and power at a high resolution. This gives immediate feedback on what is happening in the system.
Interestingly, methane gas is over 20 times more effective in trapping heat in the atmosphere than carbon dioxide . For those concerned about man-made climate change, reducing methane emissions is a critical step towards reducing greenhouse gases. For proponents of abundant energy, capturing and combusting methane gas is a step towards energy independence.
There are compelling reasons to use fiber-optic data links to transfer digital inputs and outputs (I/O) instead of using discrete copper wire in electrical substations, industrial plants, or other facilities. Because the optical fibers are insulators, they provide no path for electricity to endanger personnel or damage equipment. The data integrity is much better because electromagnetic noise does not interfere with optically transmitted data, and there are no paths for signal ground loops. The system is more reliable, because the links are continuously monitored and the number of connections is much lower . And all of these benefits come with a cost reduction instead of a cost premium!
Portable HPUs (hydraulic power units) are subject to excessive vibration and extreme temperatures that will leave commercial-grade control components susceptible to failure. HPUs will have tank-level sensors, flow meters, pressure sensors, and a variety of discrete sensors that need monitoring.
This application note covers the features of the SEL-2411 Programmable Automation Controller (PAC) and the benefits of using this device for controlling a portable HPU.
Application Note - This application note covers several features of the SEL-2414, particularly how to transmit temperature information from one SEL-2414 out to another SEL-2414.
The SEL-2440 Discrete Programmable Automation Controller (DPAC) provides discrete inputs, discrete outputs, programmable logic, and flexible communications protocols and is designed for
harsh environments. Industrial vision systems operate in locations where the product under view may change position in relation to the camera. In these locations, engineers can install a system to
move the cameras as the product position changes. As an example, we will demonstrate the use of the DPAC as an Ethernet-enabled remote I/O device for an edge inspection system in a flat-rolled
metal strip application.
Application Note - The SEL-3378 Synchrophasor Vector Processor (SVP) provides built-in modal analysis function blocks to detect unstable power system oscillations in real time. This application note illustrates how to use the modal analysis function blocks in the SVP to detect power system inter-area oscillations.
Application Note - This application note discusses useful features of the SEL-2440 Discrete Programmable Automation Controller (DPAC) when applied to control doors, lights, alarms, and intercoms in detention facilities as well as its interaction with a SCADA (supervisory control and data acquisition) master.
Application Guide - Many renewable energy resources, such as solar and wind, utilize dc to ac converters for electrical grid interconnections. During the dc to ac conversion, an inverter produces harmonics due to switching and nonideal power factor. Typically, a utility installs a capacitor bank on a distribution system for voltage and VAR support, but these capacitors also provide harmonic isolation and power factor correction that are perfect for interconnecting renewable energy resources.
Application Note - The integration and communications features in the SEL-710 Motor Protection Relay provide a method for you to include motor performance information in adaptive process control strategies. This example discusses how to use the output of the AccuTrack™ Thermal Model in the SEL-710 to not only help provide motor protection but also to optimize production for a crusher and conveyor application.
Application Note - This application note provides information on the simplest and least costly means of satisfying two generator protection and communications connection applications using the SEL-300G Generator Relay and auxiliary SEL devices.
Application Note - The SEL-587Z Relay provides bus protection using a high-impedance differential technique. Each phase has a separate differential element, providing segregated measurement. Each element has two pickup levels providing six settings in total. The differential elements compare the measured voltage with these settings.
Application Note - SEL designed the RadioRANGER Wireless Fault Indication System to solve the problem of troubleshooting faults in subsurface vaults and the underground cables between them.
Application Note - For many years, single-phase electromechanical relays (EMRs) have been used to provide protection for induction motors. These relays provide a very limited amount of motor protection and trip reporting. Microprocessor-based multifunction protective relays (MMPRs), such as the SEL-749M Motor Relay, can provide far superior motor protection and have trip event reporting capabilities that EMRs do not have.
Application Note - Power system state estimators filter power system measurements and estimate the power system state. This application note summarizes the advantages of replacing traditional SCADA measurements with synchrophasor measurements available in SEL relays for the state estimation process.
Application Note - This application note demonstrates synchrophasor measurement in the SEL-421/-451 Relay and how it can enhance the protection and control of power systems. IEEE communications protocol Standard C37.118 defines the transmission of data related to synchronized measurement as wellas supplemental data in either analog or digital form.
Application Note - This application note demonstrates how synchrophasor measurement in the SEL-421/-451 Relay can provide additional information to enhance protection and control of power systems. IEEE Communication Protocol Standard C37.118 defines the transmission of data related to synchronized measurement as well as supplementation of data in either analog or digital form.
Application Note - This application note demonstrates synchrophasor measurement in the SEL-421/-451 and SEL-311A, B, C, and L Relays and how it can provide valuable information during a generator black-start procedure.
Application Note - Motor relays must adequately protect the motor from overheating when both constant and cyclic overloads occur. Conversely, the motor relay should not trip during cyclic overloads before the motor’s thermal limit is exceeded.
Application Note - U.S. Steel, Minntac, in northern Minnesota has used microprocessor based motor protection relays since the early 1990s. In spring 2006, Pro-Tech Power Sales, Inc., met with the U.S. Steel Electrical Coordinator about the performance of the existing motor protection relays.