Fast solution of the worst load increasing direction in AC/DC power system

This paper calculates the AC network equation and DC network equation respectively, defines the coupling items between AC network and DC network, establishes the relationship equations of voltages and currents of the DC network to the AC bus voltage of the converter station as well as the presented DC control parameters, and uses the equations to calculate the coupling items between AC network and DC network. The continuation power flow method is applied to AC/DC power system, and a fast method to calculate the closest voltage collapse point and the worst load increasing direction in AC/DC power system is proposed. This method is very simple and convenient to consider the limits of DC system variables and the adjusting of operating modes, and the example system calculation shows the feasibility of this method.