基于有功无功安全约束的后续换相失败裕度预估及抑制方法OA

Improper control in high-voltage direct current(HVDC)system induces subsequent commutation failure(SCF),leading to repeated severe power fluctuations.Under various operating conditions,the AC reactive power varies significantly.From the power perspective,the commutation security constraint law can be characterized jointly by DC transmitted active power and AC reactive power,providing a new insight for control optimization.The correlation between commutation security constraints characterized by extinction angle and DC active and AC reactive power is sorted out.It reveals that the increase in active power is conditional on the reduction of reactive power or the extinction angle,and the extinction angle security can be jointly characterized based on active and reactive power.Accordingly,a margin prediction and suppression method for SCF based on active and reactive power security constraints is proposed.The effect of control on power is quantified,and the active and reactive power during fault operation can be predicted.Considering the impact of the commutation process on power,the temporal characteristics of the valve-side current are used to detect the commutation angle,increasing the prediction accuracy.A critical extinction angle satisfying the predicted power level is derived,and the deviation between this angle and the extinction angle order is used to construct an SCF margin index and a compensation order,thereby suppressing SCF.Simulation verifies that the proposed method exhibits excellent performance under various operating conditions across multiple control systems.