After the AC side short-circuit fault occurs in a multi-infeed DC system

the voltage of the AC system will continue to decrease

and will thus cause the commutation failure of multiple or even simultaneous failure of all DCs

which will seriously damage the security and stability of the power grid. The synchronous condenser has overload capability

and its reactive output is negligibly affected by the system voltage. The voltage drop caused by the AC fault can provide strong reactive power support

and can thereby suppress the occurrence of DC commutation failure. To suppress the failure of DC commutation

a synchronous condenser optimization configuration method for suppressing multi-feed DC commutation failure was proposed

which was optimized for both installation location and capacity. Firstly

starting from the duration of DC commutation failure

and taking the interaction between DCs into account

we proposed an effective index for suppressing commutation failure. Then

according to the electrical distance

the area to be selected was determined

and the best compensation location of synchronous condenser was selected by the reactive compensation response index.Thirdly

the configuration optimization model of synchronous condenser was established

and the optimal configuration scheme was solved in two stages to obtain the final configuration scheme. Finally

the actual large-grid simulation results show that the final solution can effectively suppress the multi-feed DC commutation failure caused by AC fault while considering economy.