Derivation and Enhancement of Hosting Capacity Considering Three-Phase Voltage Unbalance in Distribution System

Hosting capacity (HC) is an indicator of the amount of distributed energy resources (DER) that can be accommodated by a power system, and it has attracted attention in Japan as renewable energy deployment advances. In Japan’s 6.6 kV (classified as MV in Japan) distribution systems, PV hosting capacity has primarily been assessed based on thermal limits. However, in recent years, even below thermal limits, insufficient PV hosting capacity from a voltage perspective has emerged as an issue. Consequently, we have been conducting studies focusing on voltage aspects. Because cases of worsening three-phase voltage unbalance have been observed with increasing PV penetration, we have also advanced our investigations into deriving hosting capacity under three-phase unbalanced conditions.