The distribution network is the key power supply link for the direct connection of the power system to the user and assurance of voltage quality along the distribution network directly affects the safety and economy of the power equipment.The use of series capacitance compensation deviceto compensate the reactance of the linecan effectively improve the transmission capacity of the AC transmission line

improve the stability of the system and the voltage quality.In case of large power supply radius of lien and heavy load at the end

the voltage drop along the line is very serious and

at this time

a single compensation method is difficult to meet the requirements

and other compensation methods are needed to compensate together.As for the five typical load structures of 10 kV distribution network in this paper

the numerical simulation method is used to study the series compensation effects of different composite structures and different compensation degrees with purpose of analyzing the single series compensation mode to make the load voltage along the line meet the amplitude.The critical compensation length of the quality requirement is also studied.Meanwhile

the effects of load capacity and power factor on the compensation effect are also studied.