Testing micro inverters

Micro inverters are often used in small test setups at remote locations where AC equipment is then connected to them. This is usually done in combination with a battery. Or simply one microinverter per solar panel. They have relatively low power ratings and generally feature fast MPPT technology.

As a solar panel simulator, we can use, for example, the Itech N2100 series. The maximum voltage in this series is 150V, and there are 800W and 1500W models available. For lower power ratings with higher precision, there are also the IT2800 series and the M3600 series from Itech.

An IV curve can be generated very easily for the various types of panels. By entering the correct values for Voc, Isc, Vmp, and Imp, this curve is generated automatically.
These power supplies are exceptionally fast, allowing you to truly test the dynamic behavior of the Maximum Power Point Tracker. Tests can also be conducted according to standard specifications, such as EN50530, Sandia, NB/T32004, CGC/GF004, and CGC/GF035.

As mentioned earlier, these small inverters are also used in combination with a battery in various applications.
To test such a microinverter, we therefore use a small battery simulator. These are low-power bidirectional power supplies.

Depending on the desired power output and dynamic characteristics, we currently offer 8 different models. The Itech 2700 series stands out as a multi-channel unit (up to 8 channels) with various modules. We also need an AC grid emulator for inverters connected to the grid, or an AC load for microgrid inverters.

Just to be clear: An AC power supply alone is not sufficient because it cannot draw power. You would need to combine the AC power supply with an AC load. Fortunately, this is no longer necessary today because regenerative grid emulators are now available on the market that also feed the drawn power back into the grid.

For low-power applications such as this one, we offer Itech’s 7900 series grid emulators. The 2 kW model is usually sufficient, but there are also models with higher power ratings. For low-power AC loads, there are models from Hoecherl & Hackl (H&H) in the ACL series. This series starts at 500 W.

We also have another model from Itech that can be used as both a grid emulator and an AC load. This is the Itech 7900P series, which starts at 2 kW. It’s really convenient that you can use it for both grid-connected inverters and micro grid inverters.