Fault ride through capability for solar inverters

A solar inverter for utility scale has been developed in this paper, and the inverter has fault ride through (FRT) capability, which is now discussed in Japan and similar to requirement in U.S.A and Europe. This solar inverter consists of a boost chopper and a three-phase 2-level inverter, and the capacity covers from 20 kW to 600 kW. This paper first describes the FRT capability. Second, how to control the boost chopper and the inverter is shown. Especially, a new inverter current control to achieve FRT capability and dynamic voltage support (DVS) during a grid fault is proposed. After that, several results using an experimental model (5-kW solar inverter) are shown. Finally, results of a prototype model (20 kW), which has been installed in an actual grid, are presented.