Anti-islanding and islanding detection mitigate the risks associated with unintentional islanding of generation. Communications assisted methods eliminate the Non-Detection Zone (NDZ) experienced in local detection methods. As a result, voltage and frequency elements can be set less sensitively and reduce unwanted loss of generation.

Direct Transfer Trip (DTT)

DTT is a teleprotection signal used to prevent islanding when a power utility isolating device is opened. The signal is sent from the utility substation to the generator to initiate tripping.

Phase Comparison

Phase comparison islanding detection uses a communications channel to compare voltage phase information between the source station and generation. As an alternative to DTT, it is well suited to complex interconnection applications using multiple source stations and isolating devices or looped systems. Phase comparison reduces the necessary number of communications devices and channels.

Featured Product: GARD 8000®

Designed specifically for protection applications, this advanced communications platform provides users with a fully programmable system that can be used for Direct Transfer Trip, and Phase Comparison applications. One unique flexible platform handles analogue, digital, and Ethernet communications with multiple interfaces combined in one unit. The interfaces can be programmed together or independently, according to the needs of the application.

Features and Benefits

  • Modular platform with wide range of functional modules and diverse communications options and fully customizable logic
  • Eliminates the need for multiple devices but maintains redundancy requirements for critical applications
  • One common platform for a wide range of protection and communications applications reduces the costs associated with maintaining multiple platforms of equipment
  • Assures reliability, security, dependability, and low latency for real-time critical applications

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Utility industry and electric utility white papers by RFL providing communications and protection solutions to today's challenges, such as migrating data from leased lines.

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Multipoint-to-Multipoint Protective Relaying Signaling Using Digital Communications and Built-In Logic

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