Development of Solar Inverter with FRT and DVS Capabilities

With increasing penetration of renewable energies, especially, photovoltaic energy, more and more concern about power stability will be required because most distributed generators like solar inverters don't have fault ride-through (FRT) capability and reactive power supply capability which is called as dynamic voltage support (DVS). These capabilities haven't been required for a grid code in Japan. Penetration of large amount of PV into power system would deteriorate power system stability in the future. This paper first presents an effect of a distributed generator with FRT and DVS on voltage stability of power system by a simple simulation. Next this paper describes how to perform those capabilities of solar inverter and notes a relation between FRT/DVS and islanding. Then, we examined the methods in a factory test and manufactured a 20-kW prototype of a solar inverter with FRT/DVS capabilities. Finally we performed a field test in real power system, resulting in a good performance.