Platform of FCL Solutions

GridON is offering commercial saturated-core based Fault Current Limiters (FCL) to suppress damaging fault currents on industrial, distribution and transmission grids - enabling uninterrupted operation and keeping network stability. 

Since its infancy, the power industry has sought the means to balance between connectivity and safety. Each power source, or sub-network added to the grid, increases the operational flexibility, but at the same time, magnifies the probability of uncontrollable fault currents. The integrity of the electrical grid, and its ability to ensure reliable, consistent and efficient flow of electrical power, depends on how well it is protected against potentially disastrous fault currents.

Utilities are investing hundreds of millions of dollars in upgrading and replacing existing equipment. They often have no choice other than segmenting the grid which negatively impacts the quality and availability of their network. Independent power producers are required to make significant investments and bear long delays, before receiving permits to connect distributed generation and renewable sources. Power disruptions in many industrial plants severely impact their business and financial losses.

GridON's FCL allow for continual uninterrupted operation, while preventing fault currents from propagating through the network and thus prevent power failures, disruptions and outages.

GridON’s FCLs are in field operation in live networks since early 2013 - effectively limiting numerous faults, while proving very reliable and mature. Being scalable to very high voltage and power ratings, the commercial product is well-suited for transmission and distribution network applications. GridON’s established technology has been further enhanced to offer an economical product with smaller footprint - specifically designed for industrial and power producing customers.

This fail-safe, highly reliable current limiting device is offering the most cost-effective commercial solution. The design enables scalable solutions from distribution up to extra high voltage transmission grids. GridON's  transformer-like FCL systems are very easy to install and maintain, eliminating the costly, time and resource consuming network upgrade process.

Placing a GridFeed FCL in a transformer or generator feeder location offers great flexibility in reducing substation fault levels to accommodate switchgear ratings. One or more FCLs may be installed, depending on the fault reduction required, with minimal changes to existing protection settings. The FCL may be included in the transformer protection zone, with no additional relays or CTs required. The FCL may also be used to improve load-balancing between feeder transformers with different impedance and/or rated powers. GridFeed FCLs enable capacity increase on existing grids.

Placing a GridConnect FCL in a bus-tie location offers significant advantages in paralleling bus sections upon loss of one or more transformers in the substation. It also enables paralleling of bus sections in previously split substations, allowing interconnectivity, more flexible running arrangements and increased power quality. One or more FCLs may be installed, depending on the bus-bar topology and fault reduction required, with minimal changes to existing protection settings. The FCL may be paralleled with existing bus-tie circuit breakers, with no additional relays or CTs required.

Novel operating principles

GridON’s variable-impedance FCL combines a novel electromagnetic alteration concept with conventional transformer technology.  The self-triggered system increases its impedance instantly, suppressing the fault current for its entire duration, and recovers instantaneously following fault clearance; being always ready for consecutive faults.  The saturated-core device responds to excessive current independently of any electronic detection or switching mechanisms.  The FCL limits the fault current, but never interrupts it, making it ideal for feeder and generator connections which are very sensitive to current flow disruptions, as well as for any network tie connections. 

GridON's FCL is simple to manufacture, and is extremely reliable, easy to install, operate and maintain – like any power transformer.  While offering superior performance, it surpasses earlier FCL attempts that been bulky and expensive with a yet-to-be proven value proposition to the network operator.

A comprehensive monitoring and control system is provided with the FCL to enable seamless integration with existing protection schemes and to provide a real-time view of the FCL operational parameters. GridON offers the DR-FCL monitoring system from Dynamic Ratings as part of its solution.

Using standard technology and materials

Two main FCL paradigms have been developed in recent years; saturated-core and high temperature superconductor (HTS) based technologies. HTS-based concepts are challenging technically and commercially. Not only does it require expensive, high-maintenance cryogenic system, the HTS system takes long time to cool-down and recovers following a fault. HTS-based FCLs are limited in their scalability and their ability to handle consecutive faults.

GridON has been focusing on superconducting-free solutions that use standard transformer technology and manufacturing expertise. Our unique and proprietary saturated-core based concept is utilizing the non-linear magnetic characteristic of iron core to introduce very high impedance to the grid during fault conditions. The FCL utilizes copper windings wound onto a DC biased, pre-saturated iron core, enabling it to present very low impedance during normal operation. When fault conditions occur, the iron core is driven instantaneously out of saturation, presenting much higher impedance to the grid, thereby limiting the fault current. Upon fault clearing, the FCL immediately resumes its low impedance normal condition, ready to protect from any subsequent faults. GridON’s FCLs currently support all voltage levels and offer fault current reduction flexibility to suit the specific application and customer requirements.

Not only does our FCL suppress fault currents, it also allows for current regulation and reactive power balancing during normal conditions. The unique geometry of our design enables significant increase of impedance during fault, providing ample current limiting.

Key technology advantages:

  • Proprietary concept of magnetic-flux alteration, which changes the FCL's impedance independently of any electronic detection or switching mechanisms.

  • ‚ÄčThe FCL’s impedance rises instantaneously upon fault condition. It withstands the fault current for its entire duration and recovers to its normal condition immediately thereafter, guaranteeing protection for successive faults.

  • A very high impedance ratio between nominal and fault condition provides ample current limiting of up to 90%.

  • Standard transformer-like technology, requiring no superconducting or cryogenic components.

  • Very robust and reliable device, easy to install, operate and maintain. 

  • Scalable designs suitable for industrial substations, distribution networks and Extra High Voltage transmission grids.


Please complete the request form in order to learn more about our FCL and its capabilities.