Analysis of Distributed Photovoltaic Acceptance Capacity in Low Voltage Distribution Network

Grid-connection and utilization of distributed photovoltaic (abbr. PV) power are important ways to cope with present risks in energy source and environment, and the voltage out-of-limit caused by grid-connection of high-proportioned distributed PV power is one of the important factors restricting the ability of distribution network to accept distributed PV power. Taking enhancing the ability of distribution network to accept distributed PV power as the primary objective and considering the coordination among multi-voltage levels in distribution network, a method was proposed, which utilized the regulation and control ability of medium-voltage active distribution network and alleviated the absence of voltage regulation means via the mutual influence between medium-voltage and low-voltage distribution networks and promoted the ability of low-voltage distribution network to accept the distributed PV power. Firstly, considering time-sequence of the output of distributed PV power and load in distribution network and according to the season and weather, twelve scenarios were constructed to carry out time-sequence overall process simulation of a whole year. Secondly, an optimized operation model of 10 kV medium-voltage active distribution network and a site selecting and capacity determining model for distributed PV power in 380 V radial low-voltage distribution network were established. Simulation results show that using the proposed method the ability of low-voltage distribution network to accept distributed PV power can be enhance. Besides, the influence of grid-connection and voltage regulation of distributed PV power on the voltage of medium-voltage active distribution network and the influence of the load in low-voltage distribution network on accepting distributed PV power and voltage regulation modes are further analyzed.