- Technical Paper: A Derivation of Symmetrical Component Theory and Symmetrical Component Networks (630.4KB)
Review symmetrical component analysis.
- Technical Paper: A Practical Guide for Detecting Single-Phasing on a Three-Phase Power System (864.8KB)
Reference for the loss of one or two phases of a radial three-phase system and includes suggested detection and protection methods.
- Technical Paper: A Review of Ferroresonance (518.8KB)
The basics of a ferroresonant condition.
- Technical Paper: A Review of System-Grounding Methods and Zero-Sequence Current Sources (762.3KB)
Grounding methods, sources of ground current, ground-current flow in the power system, and how each impacts protective relaying.
- Technical Paper: A Review of Wye/Delta Transformer Connections and How They Affect Measured Current and Voltage (507.3KB)
The transformer is arguably one of the key technologies that led to AC winning over DC in the contest to distribute electricity across the US and the world.
- Technical Paper: A Survey of Cold Load Pickup Practices (668.6KB)
Cold load pickup, the causes and effects.
- Technical Paper: Analysis of Transformer Inrush Current and Comparison of Harmonic Restraint Methods in Transformer Protection (951.7KB)
Factors affecting the second-harmonic ratio in inrush current and various harmonic restraint methods.
- Technical Paper: Arc Flash Mitigation Through Use of Voltage Controlled/Voltage Restrained Overcurrent Elements (244.2KB)
The use of voltage controlled/voltage restrained overcurrent elements as an arc flash mitigation technique.
- Technical Paper: Breaker Monitoring with Numerical Relays (392KB)
Breaker duty/contact wear monitoring.
- Technical Paper: Bus-Protective Relaying, Methods and Application (1.5MB)
Application of bus-protective relaying, describing and comparing differences.
- Technical Paper: Commissioning Numerical Relays (681.2KB)
Experienced-based changes to commissioning tests and revised documentation of settings as a method for commissioning.
- Technical Paper: Considerations for Effective RS-485 Network Design (169.1KB)
Considerations for effective RS-485 network design.
- Technical Paper: Current Transformer Errors and Transformer Inrush as Measured by Magnetic, Optical and other Unconventional CTs (1MB)
Errors in secondary current for these primary current conditions determine when CTs are at risk, and show, using numerical analysis, the output of a saturated CT.
- Technical Paper: Directional Overcurrent Relaying in the Distributed Generation Environment (1MB)
Basics of directional overcurrent relaying as applied in modern numeric relays.
- Technical Paper: Effect of Transformer Connection and Construction on Single-Phasing Detection / Single-Generator Stator Protection (920.4KB)
Event, failure analysis, transformer theory, and relay solutions from loss-of-phase event at generating station.
- Technical Paper: Fundamentals and Advances in Breaker-Failure Protection (703.4KB)
Deciding whether to apply dedicated breaker failure protection.
- Technical Paper: Ground Differential Protection: Revisited (265.3KB)
Principles of ground differential protection within industrial power systems.
- Technical Paper: Harmonic Sharing for Effective Detection of Transformer Inrush Condition in Differential Protection Scheme (564KB)
Harmonic sharing in transformer differential protection improves security for some inrush conditions, while maintaining sensitivity.
- Technical Paper: Life Lessons from the Power System (681.3KB)
Explores the basic principles of relay protection design and relay protection commissioning, while reflecting upon lessons learned.
- Technical Paper: Power Quality: Measurement of Sags and Interruptions (362.9KB)
Measurement of power quality use of meters for residential and small commercial customers as a tool to track outage issues.
- Technical Paper: Predicting Current Differential Relay Tripping (1.6MB)
Testing current differential relays at final settings.
- Technical Paper: Protective Relaying Methods for Reducing Arc-Flash Energy (653.1KB)
Arc flash standards/requirements and high-speed detection and operation techniques used to reduce arc-flash energy via protective relays.
- Technical Paper: Reliability Considerations of Multifunction Protection (331KB)
Reliability of numerical multifunction protection systems against predecessor technologies.
- Technical Paper: Solutions for Unconventional Connection of Transformer Differential Current Transformers (982.3KB)
Analyzing unconventional current-transformer polarity connections and how to obtain the right connection to achieve the desired direction of operation or polarity.
- Technical Paper: Three Phase Transformer Winding Configurations and Differential Relay Compensation (1.2MB)
How a transformer differential relay compensates for the effects of the various transformer winding configurations.
- Technical Paper: Upgrading Relay Protection? - Be Prepared. (336.4KB)
Guidance for your next replacement or upgrade project.
- Technical Paper: Using Iop Characteristics to Troubleshoot Transformer Differential Relay Misoperation (1.2MB)
Transformer differential false trips and methods to alleviate this issue.
- Technical Paper: Voltage Restrained Time Overcurrent Relay Principles, Coordination, and Dynamic Testing Considerations (330.1KB)
Dynamic response of 51/27R relays in which the overcurrent element conforms to the dynamic characteristic defined in ANSI C37.112.
- Technical Paper: Zero-Sequence Circuit of Three-Legged Core Type Transformers (648.5KB)
Modified zero-sequence equivalent circuit for a three-legged core-type transformer.
- Technical Paper: Zero-Sequence Impedance of Overhead Transmission Lines (716.5KB)
Transmission-line impedances, centering on zero-sequence impedances.