The distribution network is a power network that receives electric energy from the transmission network or regional power plants and distributes it locally or step by step to various users through distribution facilities. It is composed of overhead lines, cables, towers, distribution transformers, isolating switches, It is composed of reactive power compensation capacitors, metering devices and some ancillary facilities. It generally adopts closed-loop design and open-loop operation, and its structure is radial.
The distributed photovoltaic system is connected to the distribution network, so that power generation and electricity consumption coexist in the distribution system. The structure of the distribution network changes from a radial structure to a multi-power supply structure, and the size, flow direction and distribution characteristics of the short-circuit current change.