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This webinar focuses on the new SEL-RP50 Fault Repeater and SEL-FT50 and SEL-FR12 Fault Transmitter and Receiver System, a simple and cost-effective solution for utilities to enhance distribution protection. During the webinar, you will learn about …
This webinar discusses how an SEL powerMAX remedial action scheme (RAS) solution helps the bulk power system function closer to stability limits and prevents blackouts. We also cover how to operate transmission corridors m…
This webinar introduces the SEL Blueframe and Data Management and Automation applications. During the webinar, you will learn how these new solutions support your efforts in increasing system security, efficiency (ease of use), and data utilization.
This webinar explains CT saturation in an intuitive way using simple animations and avoiding complex math and physics. We examine symmetrical and asymmetrical saturation, remanence, the equivalent circuit of a CT, and CT excitation graphs. We also…
This webinar focuses on how SEL powerMAX commercial microgrids provide greater resiliency, seamless islanding from and reconnection to the bulk electric system, and simultaneous energy storage management—maximizin…
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.
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.
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.
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 - Using the SEL-735 to Display Multiple Metering Values
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?
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 - 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 - 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 - Directional relays must be wired with proper current polarity (on the current transformer [CT] and relay terminal) in order to operate properly for faults. The polarity defines the forward direction of the directional protection elements of the relay. In many applications, the metering functions of digital relays are being used to replace separate supervisory control and data acquisition (SCADA) metering equipment. The direction of power flow (both watts and VARs) for this metering is also defined by the polarity of the CT circuit. This can create a problem because certain SCADA applications require the direction of power flow for metering to be opposite of the direction for protection elements. Automation math variables available in SEL-400 series relays can be used to invert the metering values for these applications.