Hardware-in-the-Loop Low Voltage Fault Ride Through Tests of Commercial Photovoltaic Inverters

Abstract

Due to the increase in the installed power of dis-tributed photovoltaic generation, this paper proposes a method-ology for pre-certification of the firmware of commercial PV inverters, where the power circuit and the test equipment are emulated in HIL, while the control of the PV inverter is done externally with a microcontroller. This paper describes the proposed pre-certification process and how the tests are performed in an automated way using Python scripts and HIL. The paper focuses on the Low Voltage Fault Ride Through, LVFRT, tests and the possible problems that can be caused if the PV inverter does not meet the requirements for supporting grid faults. Finally, experimental results for the LVFRT tests are presented to demonstrate and validate the proposed pre-certification process. The main goal of this methodology is to accelerate the development of commercial PV inverters, providing manufacturers with reliable results on how the real inverter should behave.