V2G Standardization and Grid Codes: Certification Testing is not Optional
Vehicle-to-grid (V2G) turns an EV battery from a load into a grid asset, and the moment a vehicle can export power, it becomes a distributed energy resource (DER) that has to prove it will behave properly when grid conditions change. That behavior is referred to as grid code — and for V2G it is the must-conform gate to get through.
Grid codes are regional by design
A grid code defines the functions a DER must perform to support the grid: active and reactive power control, voltage and frequency ride-through, anti-islanding, and the response curves that govern how a device reacts as conditions drift out of acceptable range. Critically, these are not global. Grid code functions carry different defaults in each region, and every country sets its own requirements based on local grid needs. In North America, IEEE 1547-2018 and IEEE 1547.1-2020 govern DER interconnection and conformance testing — mandatory in a growing number of states— with UL 1741 SB the supplement devices certify against. The EU is working to standardize on their EN 50549. Australia requires conformance to AS/NZS 4777, and other regions have their own codes. A product certified for one market is not compliant in another.
Why V2G raises the bar
A solar inverter exports one way. V2G adds bidirectional flow, a moving vehicle, and a question of where the grid-code functions live. In V2G-DC, the inverter sits in the charging station, so the EVSE is the DER. Same grid-code intent; different device under test, and only the EVSE needs to be certified for grid code compliance.
In a V2G-AC system, the bidirectional inverter sits in the vehicle: the grid-code functions run on the EV or are split between the EV and the charging station, and what gets certified are the EV and EVSE components independently. There is an interim standard that certifies a matched EV-and-EVSE combination but then only that combination can be interconnected and provide V2G services to the grids.
Testing grid codes for V2G-AC
Verifying compliance means testing a device (either the EVSE or the EV with inverter) through every required function with a grid simulator and capturing whether its response stays within the standard’s limits. QualityLogic’s grid-code test bed is built for both topologies — grid-code test control software driving a grid simulator with automated data collection, using an EV emulator for V2G-DC or a real EV for V2G-AC.
For V2G-AC in North America, certification includes both validating a J3072 protocol (IEEE 2030.5, SunSpec Modbus, or ISO 15118-20 Amendment 1 in the future) and validating effectively UL 1741 SB compliance of the EV with UL 1741 SC compliance for the EVSE. The practical implication for an OEM is that the V2G-AC path requires both communications-interoperability and grid code compliance.
In the EU, a different division of functions between the EV and EVSE is being codified in a set of updated standards. But each component (EV and EVSE) is independently tested and certified for both grid-code and communications compliance.
Where QualityLogic fits
QualityLogic built the first automated certification test product for UL 1741 SB certification testing, supporting the DER protocols IEEE 1547 requires — IEEE 2030.5, SunSpec Modbus, and IEEE 1815.2 — and working closely with major NRTLs globally to keep testing standardized and consistent. The same framework automates grid-code execution end to end for OEMs and test labs, including V2G-DC EVSEs, and it is the foundation QualityLogic is extending into V2G-AC certification testing in both North America and the EU.
If you are scoping a V2G-DC or V2G-AC program and need to know what your grid-code and certification path actually looks like, talk to us about our test tools, training, and consulting.
