In EU and Australian projects, Italy and Australia are known for the thickest documentation and the most detailed testing. Both require inverters not only to connect, but to respond to grid instructions.
1. Italy CEI 0-21: reactive curves and overvoltage power reduction
- Reactive capability: triangular curve up to 11.08 kW; rectangular curve above 11.08 kW with Q up to ±48.43% Pn at any P.
- Ride-through: above 11.08 kW, UVRT (0.05 pu for 0.2 s, linear recovery to 0.85 pu between 0.2 and 1.5 s) and OVRT (1.25 pu/100 ms, 1.20 pu/500 ms), including asymmetrical faults.
- Overvoltage reduction: active power reduction near 110% Un at no more than 33% Pn per second.
- Intentional islanding: capability to support local island operation on DSO instruction.
2. Australia AS/NZS 4777.2 Amd 2:2024
- DRM interface: mandatory demand-response capability via DRED.
- Response modes: Volt-Watt, Volt-Var, fixed power factor/reactive power, ramp-rate limits.
- BESS specifics: earth-fault/leakage detection for battery systems; multi-mode operation includes storage charging Volt-Watt and independent supply.
- Energy isolation: separate requirements for isolator, breaker, PV port and battery port.
3. What Chinese manufacturers hit
Both markets require grid-commanded behaviour: Italy requires DSO remote reactive control with priority over local logic, Australia requires the DRM interface. Many products handle local control well but leave remote priority and fallback strategy unclear, which fails commissioning. Put the remote command layer above local strategy in the firmware architecture and define behaviour on communication loss.
Related service: PV inverter grid-connection certification