Equipment tested by type

INTEGRATION – HARMONISATION – IMPLEMENTATION

You must obtain all the elements listed above when importing your electricity-generation equipment into the United Kingdom. This has become much more difficult, as all the aforementioned implementation areas are now governed by the technical recommendations G99/2, and if you do not comply with these Engineering Recommendations (ER), your equipment cannot be connected to the grid in parallel.

The ER G99/2 document aims to address all aspects of the connection process, from functional standards to on-site commissioning, so that customers, manufacturers, and generators understand the requirements that will be imposed by the local DNO (Distribution Network Operator) before a power-generation installation is approved for connection to the distribution network.

The guidelines provided in the ER G99/2 document aim to facilitate the connection of electricity-generation module(s) while preserving the integrity of the distribution network in terms of safety and supply quality. They apply to all power-generation modules within the scope of Section 2, regardless of the type of electrical machine or equipment used to convert any primary energy source into electrical energy.

Developers and suppliers of generation equipment
Designers and suppliers of generation equipment must be familiar with the new G99/2 regulations to ensure that their products are capable of meeting these higher performance requirements.

Applecoat Ltd can simplify this process for any importer from any country. We can obtain type-testing for your equipment and register it with the appropriate authorities. We can also establish connectivity with any distribution network operator in the United Kingdom.

As part of our service offering, we can also conduct on-site witness tests, which DNOs may still request even after full type-testing has been completed, as they are entitled to request such tests.

The protection settings of a type-tested interface are defined during manufacture. The regulations define type-tested equipment as “a product that has been tested to ensure that its design meets the relevant requirements of G99/2.” All similar products will be built to the same rigorous standards and meet the same performance levels.

Non-type-tested interface-protection systems require additional tests and measurements to assure the regulator that the protection being used is sufficiently robust.

When familiarising yourself with the G99/2 document, you must also consider all the following areas, in which UK DNOs are showing increasing interest — as shown below.

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Frequency-Response Requirements

Generators must now control their active power output in response to changes in grid frequency. The frequency-response requirements are divided into two modes: Limited Frequency Sensitive Mode (LFSM) and Frequency Sensitive Mode (FSM).

The Limited Frequency Sensitive Mode requires generators to reduce their active power (MW) if frequency exceeds 50.4 Hz and increase their active power if frequency drops below 49.5 Hz.

Frequency Sensitive Mode (FSM) imposes a more demanding requirement for larger generators and requires the installation of a fast-acting proportional frequency-control device that can respond to frequency changes and quickly increase or decrease active power by 10%.

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Fault-Ride-Through Requirements

Generators over 1 MW must now remain connected to the grid during significant voltage dips caused by network faults. This is known as fault ride-through capability and helps prevent power outages by ensuring that if one generation site trips due to a fault, it does not cause other sites to disconnect.

The required stability during voltage dips varies with generator size, with the largest generators required to withstand a total voltage loss for 140 ms.

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Requirements for Fast Fault-Current Injection

Generators over 1 MW must also support the system during a fault by rapidly injecting reactive current so that the grid voltage does not drop too low. This capability helps prevent the loss of additional consumers and generation sites during faults by keeping the grid voltage as high as possible.

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Voltage-Control Requirements

G99/2 requires generators to have a voltage-control system capable of injecting or absorbing reactive power to regulate voltage. The DNO will instruct the generator to operate in one of three modes:
• voltage control
• reactive-power control
• power-factor control

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Reactive-Power Capability

Reactive-power capacity requirements have also been strengthened. For power-generation modules between 1 MW and 10 MW operating at rated capacity, they must allow continuous operation between 0.95 lagging and 0.95 leading at the connection point.

Larger generators have specific reactive-power capability windows within which they must be able to operate at all times.

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Applecoat Ltd can obtain type-testing approval and advise you on any importation of power-generation equipment you bring into the United Kingdom.

If you simply need more training and general information regarding the G99/2 or G98/1-2 documents, why not visit our online training portal, where you can view the information in English, German, French, Spanish, or Italian.