It is of prime importance to maintain voltage profile in distribution systems with a large number of renewable energy sources such as photovoltaic generators. Voltage control is available by using existing voltage control equipment with tap position control. However, there is a possibility that proper adjustment of control parameters of those control equipment is needed to enhance their control performance with the penetration of photovoltaics. To this end, in this paper, a new LDC logic was proposed based on the combination of two sets of control parameters. The effectiveness of the proposed method was shown by using 37-node distribution system model.