A Study on Voltage Rise Control Effect by Leading Power Factor Operation of PVs Considering Tap Change of Distribution Transformer

摘要

The voltage rise problem in distribution networks has been discussed as the foremost concern against the penetration of large amounts of photovoltaics (PVs). As a solution of such a problem, using voltage regulation facilities such as SVC (Static Var Compensator) or Loop power flow controller has been proposed. However, this might require major investments in the distribution network and that means the cost would be imposed on the nation. In this paper, the authors focus on the latent ability of the present distribution network and PVs to find solutions to the problem and propose a low-cost solution to mitigate the voltage rise by using constant leading power factor operation of PVs. The distribution voltages are calculated in the case of increasing highly penetrated PVs, where it is very important to make an aggregated model of the distribution networks including loads and PVs. The authors aggregate many loads and PVs by using an aggregation method called "Y-connection." As a result of simulation with the aggregated realistic model of distribution networks, the authors confirmed that using a combination of leading power factor operation with Q = -0.2P and the LDC of the distribution transformer makes it possible to maintain adequate voltage without voltage regulation facilities such as SVC.