EMT models and grid-code compliance for GB connections.
For generators, inverter manufacturers and developers connecting in Great Britain. We build the validated models and produce the compliance evidence the connection now legally requires.
In GB, an EMT model is no longer optional.
Under the GB Grid Code (PC.A.9, brought in by GC0141), new generators and inverter-based plant above the small-power threshold must supply a validated three-phase EMT model and show compliance before they can energise. NESO can ask existing owners too. For converter plant that means proving ride-through, fast fault current and no subsynchronous oscillation, not just steady state.
Stay connected through the dip, and support the grid.
The GB Grid Code requires plant to ride through voltage dips along a defined envelope and inject fast fault current while it does. We set up the ECP.A.3.5.1 dip cases in EMT, demonstrate the plant stays above the boundary, and plot the reactive current delivered at the point of connection. That is the evidence the connection review needs.
Catch the oscillation before the grid does.
Subsynchronous oscillation is the risk a 50 Hz study never shows. We scan the plant's dq impedance across frequency, flag every band where its real part turns negative, and check the stability of plant and grid together.
We did exactly this on a real 40 MW battery: a full impedance scan, eigenvalue Nyquist and time-domain injection, all stable across the band.
From model to approval, in four steps.
Build / audit the model
We build your EMT and RMS models, or audit and fix a vendor model, to the structure the checklist asks for, with encrypted blocks documented.
Run the mandated studies
Fault ride-through, FFCI, voltage injection, reactive capability and frequency response, with each case set up and plotted for review.
SSO screening
Active impedance scan and eigenvalue stability across 1–500 Hz, corroborated by time-domain injection.
Validate & submit
Model verification and validation reports, cross-referenced to factory, type-test and on-site results, packaged for the operator.
We work for the generator, the inverter manufacturer and the developer, the people who have to deliver the model. The same team builds it, studies it and signs off the evidence.
Real compliance projects, start to sign-off.
Two recent GB projects, an inverter-based connection study and a generator re-compliance, show the same package from start to finish.
40 MW BESS · SSO screening
Sub-synchronous oscillation screening for a grid-connected battery: PSCAD/EMTDC injection tests and an MHI impedance scan, showing stable, well-damped behaviour from 1 to 500 Hz.
View the case study →Generator · controls changed
A synchronous generator that changed its controls and had to show Grid Code compliance again. We rebuilt the full EMT model (machine, excitation, stabiliser, protection) and checked it against site measurements.
View the case study →