To improve the application of AC ice—melting technology in power grids,a new type of based on cascaded STATCOM ice—melting technology was proposed.Based on analysis on the equivalent model of frozen transmission lines and the heat exchange during ice-melting,the necessary anti—icing current and maximum current were calculated for a 35 kV power line,according to the calculation results.The main circuit topology was designed,mathematical model and control strategy of the power unit module were introduced and discussed.Finally By using matlab ,the simulation is made.,Test results show that the ice—melting device can regulate reactive current output flexibly。