PV inverter grid-connection testing: one product, many grid codes

#The grid codes by market

Anti-islanding is commonly tested with IEC 62116, which defines a repeatable procedure for utility-interconnected PV inverters.

#The functions behind every code

Grid codes differ in numbers, not in ideas. Almost every market tests:

• Voltage and frequency protection — trip limits and clearing times.
• Ride-through — staying connected through voltage and frequency disturbances (LVRT/HVRT, frequency ride-through).
• Active power response — reducing or increasing output as frequency changes, plus ramp rates and reconnection behaviour.
• Reactive power — fixed power factor, cos φ(P) and Q(U) characteristics.
• Anti-islanding — detecting loss of the grid and disconnecting in time.
• Power quality — harmonics, flicker and DC injection.

What changes between markets is the parameter set: limits, curves, times and the order of priorities. That is why most manufacturers build one hardware platform with country profiles in firmware.

#How to plan one programme for several markets

1. Freeze the hardware and the firmware architecture first. Country profiles should be parameter sets, not separate code branches.
2. Group tests by function, not by standard. One ride-through campaign with several parameter sets is faster than repeating the set-up per market.
3. Use a grid simulator and a PV simulator that cover the highest voltage, current and power of the product family.
4. Test the largest and smallest model of a family and justify the rest by design similarity, where the scheme allows it.
5. Plan the certificate route per market. A CB report and CE documentation can share safety data, while grid-code certificates usually need market-specific reports.

#Storage inverters and hybrids

Battery and hybrid inverters connected to the grid follow the same grid codes when they export power, and AS/NZS 4777.2 explicitly covers multiple-mode inverters. Bidirectional operation adds charging-mode tests and, in Europe, a coming requirement for grid-forming behaviour on larger units.

Our partner laboratory network tests PV and storage inverters up to 2.5 MW for grid connection, ride-through and power quality, together with safety and EMC.