Breakers & Relays
Dynamic Resistance Measurement
Power Factor Testing of Circuit Breakers
Breakers & Relays

Protective Relay Frustrations
Solving misoperation with line parameter measurements
BY WILL KNAPEK, OMICRON USA
Between 80 to 90 percent of all power system faults involve ground. Many protective relaying schemes depend on ground distance protection to accurately sense and locate ground faults on multi-terminal sub-transmission and transmission lines. In addition to the need of dependable ground fault detection, protective relay devices must provide adequate selectivity to avoid overtripping for faults outside of its zone of protection and other...
Related Articles

Power Factor Testing of Circuit Breakers
Detecting contamination and deterioration in SF6 breakers to ensure longevity BY LINDA NOWAK, Doble Engineering Company The purpose of “Doble testing”, or power factor testing, SF6 (sulfur hexafluoride) circuit breakers is to detect the presence of contamination and/or deterioration of the...

Selecting Substation Medium-Voltage Switchgear: GIS vs. AIS
Understanding differences between GIS and AIS in five points BY GAETAN DJENANE, Schneider Electric, Inc. Many considerations must be taken into account before selecting the electrical medium-voltage (MV) switchgear that best meets a user’s needs. From a management perspective,...

Effective and Safe Testing of GIS Switchgear
To fully assess the functionality of medium and high voltage circuit breakers, various mechanical and electrical parameters must be tested. Gas-insulated switchgear (GIS) in particular poses unique and special challenges, including the connection of the test equipment. In today‘s world, where...

FERC Complaint Targets Duke, PJM Transmission Planning
A coalition of large energy consumers and ratepayer advocates has filed a complaint with the Federal Energy Regulatory Commission (FERC), urging the agency to prohibit transmission owners from independently planning "local" transmission projects exceeding 100 kilovolts (kV). The coalition argues...

FERC Complaint Targets Duke, PJM Transmission Planning
A coalition of large energy consumers and ratepayer advocates has filed a complaint with the Federal Energy Regulatory Commission (FERC), urging the agency to prohibit transmission owners from independently planning "local" transmission projects exceeding 100 kilovolts (kV). The coalition argues...

FERC Approves Interconnection for Talen Energy, Amazon Data Center
In a significant move that underscores the growing demand for reliable and sustainable energy to power the expanding digital infrastructure, the Federal Energy Regulatory Commission (FERC) has approved an interconnection agreement between Talen Energy, Amazon Web Services (AWS), and Exelon. This...

SAME DAY SWITCHING
Same day switching avoids the extended outages and human and equipment costs associated with inoperable and broken switches.The vast majority of air break disconnect and ground switches in electric power networks typically receive no appreciable maintenance. This invariably results in the inability...

Effective and Safe Testing of GIS Switchgear
To fully assess the functionality of medium and high voltage circuit breakers, various mechanical and electrical parameters must be tested. Gas-insulated switchgear (GIS) in particular poses unique and special challenges, including the connection of the test equipment. In today‘s world, where...

Reconditioned SF₆ Gas: An Environmentally Friendly Alternative
When it comes to medium and high voltage circuit breakers, there is no better electrical insulator than sulfur hexafluoride (SF6). The manufactured gas is most commonly used to fill circuit breakers within utility substations to prevent and quench arcing events. SF6's impeccable dielectric...

Protection of Electrical Power Transformers
INTRODUCTIONIn most large electrical systems, generators and power transformers are the two most expensive pieces of equipment. In addition to the capital cost of purchase, these two key devices are also the most critical to continuous and reliable operation of the system.Consider, for example, the...