抄録
At early stage of PV's (Photovoltaic) penetration, heavy leading power factor operation was adopted so that LV might be reduced within regulation (107V in Japan). However, such an excessive reactive power control claims additional capacity in PCS (Power Conditioning System). In addition, such a local control could not realize desirable voltage all over distribution network, and as the result, could not realize desirable voltage of the PV itself. Behind such a control procedure lies misunderstanding of distribution network. It must be noticed that impedance of distribution transformer is almost pure reactance and larger than MV and LV network impedance. Therefore, distribution transformer and its tap control are the most prominent elements in distribution network voltage regulation. In this paper, the reason why light and constant leading power factor operation of PVs is sufficiently effective for mitigating overvoltage and voltage fluctuation in distribution network (especially when combined with transformer tap control by vector-LDC: Vector-computed type Line [voltage] Drop Compensation) is clarified through analysis on aggregated network model and simulation on a realistic detailed network model. Moreover, the contribution to energy saving of this combination is demonstrated.
