VDCOL link optimization of HVDC system based on improved genetic algorithm

The fault of the receiving-end AC power grid of the high voltage direct current (HVDC) transmission system may cause the HVDC subsequent commutation failures. In order to dynamically adjust the DC current command during the recovery process of the first HVDC commutation failure to achieve the purpose of suppressing the HVDC subsequent commutation failures, a new method is proposed based on improved genetic algorithm (IGA) of the voltage dependent current order limiter (VDCOL) link optimization method. This paper analyzes the influencing factors of HVDC subsequent commutation failures and the reactive power interaction between the inverter converter station and the external power grid. Taking VDCOL as the research object, the work principle and limitations of conventional VDCOL are introduced. In order to overcome the single linear defect of the conventional VDCOL link, an IGA was used to optimize the parameters of the multi-segment inflection point of the VDCOL link, which realized the dynamic reactive power demand adjustment of the inverter side converter station when the receiving-end AC power grid was faulty, and then suppress the HVDC subsequent commutation failures. Finally, the simulation results demonstrate the effectiveness of the proposed method.