Background
Client: Undisclosed
Industry: Waste-to-Energy
Location: Devon, UK (Southwest)
Date: February 2025
In-depth grid code compliance and connection studies for the integration of a 2.9 MVA ORC synchronous generator into an 11kV distribution network.
Explore Our Project in Detail:
Engineering Recommendation G99 Studies
P28 Voltage and Flicker Studies
G5/5 Harmonic Compliance Studies
Project Overview
A UK-based renewable energy facility required comprehensive grid code compliance and connection studies to support the integration of a 2.9 MVA ORC synchronous generator into its existing 11kV network. Our scope included:
- EREC G99 Grid Connection Studies
- P28 Voltage & Flicker Studies
- G5/5 Harmonic Analysis
EPS delivered specialist power system modelling to ensure the generator’s seamless integration and determine compliance with UK grid connection standards.
G99 Grid Connection Studies
Our power system engineers developed in-depth DIgSILENT PowerFactory models to simulate the new generator’s performance across key compliance areas. This included:
- Voltage & Reactive Power Capability
- Fault Ride Through (FRT)
- Frequency Response
- Limited Frequency Sensitive Mode – Overfrequency (LFSM-O)
Each operating scenario was evaluated against the permissible limits outlined in (ENA) Engineering Recommendation G99, confirming full compliance at the Point of Common Coupling (PoCC).
P28 Voltage & Flicker Studies
Using ETAP, our team assessed voltage fluctuations and rapid voltage changes during energisation, generator tripping, and motor starting events, determining acceptable voltage dips for both infrequent (7.5%) and frequent (0.3%) events and full compliance with P28 flicker thresholds.
G5/5 Harmonic Compliance Studies
National Grid required a Stage 2C G5/5 harmonic assessment with the integration of the new generator. For this, EPS conducted:
- Background harmonic monitoring
- THD and individual harmonic voltage simulations
- Future harmonic distortion projections (THDVp, Vhp)
All outcomes were found within G5/5 planning levels, ensuring harmonic compatibility with the client’s existing infrastructure.
Conclusion
Overall, the comprehensive suite of grid code compliance studies delivered by EPS (G99 / P28 / G5/5) confirmed that our client’s new 2.9 MVA ORC synchronous generator meets all applicable UK grid code requirements. The detailed modelling and analysis conducted by our power system experts validated the generator’s ability to operate under various fault, frequency, and harmonic conditions. The client’s waste-to-energy facility was shown to operate well within the allowable thresholds for voltage dips, flicker, and harmonic distortion.
As a result, the generator is now fully configured for long-term, standards-compliant operation within the UK transmission and distribution (T&D) network.
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