With the high-quality development of the economy in recent years

the demand for electricity in Jiangsu Province has been increasing year by year

which will put great pressure on the safety of power supply in some 220?kV regional power grids.In response to the problem of small power supply margin and insufficient power supply capacity in some typical 220?kV district power grids

the paper proposes to embed the technology such as phase shifting transformer and back-to-back DC transmission into 220 kV district power grid

which takes it as a means of mutual flow and on-demand control of the the main transformer load rate in higher-level 500?kV substation.This planning approach considers the full utilization of power grid existing resources as the basis and enhances the power supply capacity of district power grids through flow control

which can provide reference for the planning and development of large-scale 220?kV district power grids in other provinces and cities.