Test Setup for Anti-Islanding Testing

In addition to the required AC grid emulator, the RLC load generally represents the greatest challenge. Depending on the type or model of the DUT, this RLC circuit must be adjusted to simulate the correct grid impedance at different power levels.

The Itech IT7900 series grid emulators are fully four‑quadrant, regenerative, and bidirectional, with the capability to simulate the required RLC network as needed for anti‑islanding tests.

RLC‑load capacity

One of the mandatory anti‑islanding tests is verifying that a DER ceases energizing and disconnects as specified in IEEE Std 1547 when an unintended islanding condition occurs. This requires an adjustable RLC load as part of the test setup. The IT7900 series regenerative grid emulators support emulation of the islanding condition through the RLC Electronic Load mode. The disconnection time is also determined in this mode. This simplifies both the installation and the time required to perform anti‑islanding tests in accordance with IEEE 1547 on PV inverters and other distributed energy resources (DERs).

Users can adjust RLC parameters or configure active and reactive power parameters to simulate the islanding state between inverter and load when the grid is disconnected. This makes it relatively easy to verify the anti‑islanding response time of grid‑connected DUTs under different load impedances, three‑phase load balancing, and unbalanced conditions.

This solution helps developers and test engineers simplify the test circuit and reduce costs for additional equipment such as discrete RLC impedances, oscilloscopes, and power meters.