Evaluation of generation efficiency and voltage deviation in residentail clustered PV voltage control

Installation zero-emission power sources, including photovoltaic power systems (PV), is necessary to cut greenhouse gasses to reduce global warming. In Japan, the target capacity for installed PV in 2020 has been set at 28 GW, which is 20 times the 2005 capacity. PV should be installed in 70 percent of new houses to reach this target. The PV output (active power) must be suppressed to sustain adequate voltage (within 101±6 V), due to voltage increases by inverse power from PV when clustered residential PV systems are grid-interconnected on a distribution line, even if there is sufficient irradiance. Simulation software was developed to analyze voltage increases when clustered PV were grid-interconnected on a large-scale demonstration research in Ota City in Japan. From the previous fiscal year, the authors started to research how to improve whole generation efficiency at a site and balance it among all the residences through voltage control including power conditioning systems of a clustered residential grid-interconnected PV with the developed simulation software. For the subject, we have already demonstrated that 25 percent of the output suppression loss was eliminated with reactive power control when 225 residential PV are grid-interconnected to a single distribution line. In this research, we have evaluated the influence of increasing and decreasing active and reactive power rate in residential PV voltage control on voltage deviation.