Hardware in the Loop and Experiment Validation for a PV Inverter Under Flexible Power Control

Solar intermittency is the primary problem for the PV power generating system with a principal challenge of PV of the weather. Flexible power point tracking (FPPT) control can be incorporated into the system to allow dual-mode control approach between Power Ramp-Rate Control (PRRC) and Maximum Power Point Tracking (MPPT) control to address these issues. This paper develops a testbed platform which includes a hardware-in-the-loop (HIL) simulator, a real inverter, and loads to validate the operation of FPPT control under the realistic irradiance profile. The scaled down setup of the proposed framework with the inverter output limit of 600 W is used for the experimental validation. The output power from the HIL inverter model and the real inverter are compared in 4 modes of operation. Overall, the results from the HIL simulation model agree well with the experiment with slight deviation in the ramp down mode. The experimental framework presented here is intended for stand-alone PV system test, however, we should be able to extend for a test of higher power and more complex system such as microgrid where inverters will be grid connected and loads will be of various power profile.