A G99 relay is a main protection device that helps users monitor voltage, frequency, and loss of mains conditions to safely disconnect distributed energy resources from the grid.

A G99 relay are a crucial device that provides safety and efficient operation of generation equipment connected to the UK electricity distribution network. A generation relay offers protection against that could affect the grid or the generator itself. Compliance with the G99 regulation is essential for all generated systems, this includes solar PV systems and battery storage to ensure that they can connect to the network safely and effectively.

The G99 regulation came into effect in April 2019, this regulation applies to new power generation or storage plants seeking connection to the UK electricity distribution networks. G99 applies to generating units with a capacity exceeding 16A per phase, including large-scale solar farms, wind farms, and energy storage systems.

Key Requirements and Specifications:

  • More stringent protection settings and control capabilities
  • Fault Ride Through (FRT) capabilities for larger systems
  • Reactive power control requirements
  • Extensive testing and commissioning procedures

Application Process:

  • More complex than G98
  • Requires prior approval from the DNO before installation
  • Detailed application forms and technical information required
  • May involve site-specific studies and simulations

 

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Grid Feeding Monitoring Relay

CM-UFD Series 

ABB has created an innovative monitoring relay that helps detect unusual events in the public power grid. ABB’s grid feeding monitoring relay CM-UFD helps monitor the stability by automatically disconnecting and reconnecting the renewable power plant

The CM-UFD series provides a display of all relevant measuring data and events that can be communication via a build-in communication interface. A cloud-based service ‘Energy Manager’ is available with the is grid feeding monitoring relay that enables users to monitor conditions in real time, and sending the data into the cloud but also enabling access to the diagnostics remotely.

So why should you add the CM-UFD into your next project.

The CM-UFD multi functioning grid monitoring relay offers a interface protection that can be installable between a renewable energy system and the public grid. By having these innovative relays it guarantees grid stability and reducing the risk of a black out.

If the voltage or frequency magnitudes of the public grid are outside the permited range, then the devices change status and act to disconnect the renewable energy system from the public grid by sending a signal to a decoupling unit (e.g. contactor, switch disconnector or circuit breaker).

 

 

 

 

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Advantages

  • Highly accurate measurement and setting.
  • Modbus RTU communication interface and ‘Energy Manager connectivity.
  • Functional safety – Single fault tolerances
  • Clear multiline backlit LCD
  • Intuitive and user-friendly menu
  • Event storge
  • Pre-settings meet several local standards
  • Type-tested by 3rd part certification.

 

 

 

 

Easy installation and maintenance

Operate the device remotely and monitor your renewable energy plant. The CM-UFD´s display, communication interface, pre-setting and Modbus RTU reduce installation and configuration times by up to 60%

If you would like to have further information on the G99 regulations or the ABB CM-UFD series please contact your local branch!