In distribution network, the short-circuit current generated by photovoltaics will inevitably affect the reliability and sensitivity of the existing protection with the increasing penetration of photovoltaics. In order to analyze the impact of photovoltaic access on Instantaneous Overcurrent Protection and Definite Time Overcurrent Protection, a calculation method of photovoltaic maximum accessible capacity based on the existing protection configuration was proposed. Two factors of the photovoltaic maximum accessible capacity, length of feeder line and capacity of short circuit, were analyzed respectively through the discussions under two boundary conditions. A simulation model was established on DIGSLIENT platform to verify the conclusion.

photovoltaic access,maximum accessible capacity,distribution network,current protection