With the development of ultra-high voltage AC/DC technology and the expansion of ultra-high voltage AC/DC projects

the voltage support problem of the AC system in the DC receiving system of the power grid is becoming increasingly prominent.When commutation failures occur in HVDC transmission lines

it will lead to an increase in DC current and a decrease in DC transmission power.In serious cases

it leads to a DC blockade

which will lead to a large-scale power transfer on AC channels

and may threaten the transient stability of the DC receiving system.The common treatment method is to cut off a large amount of load

but it can also cause significant economic losses.It uses transient voltage drop indicators to form risk indicators as a measurement basis.It proposes a load prevention control strategy for the receiving system considering DC faults

improving the transient voltage margin after accidents

reducing the degree of risk

and thereby reducing the amount of load shedding.The PSASP simulation results in actual examples demonstrate the effectiveness of this strategy

providing a reference for the stable operation strategy of ultra-high voltage DC receiving systems.