提高特高压直流运行可靠性的分接开关优化控制策略OA北大核心CSTPCD

The tap changer of converter transformers is a key component in UHVDC systems.Severalinstances of forced converter outages or equipment damage have been attributed to tap changer faults.Reducing the action frequency of tap changers can decrease the probability of equipment fault and increase the reliability of UHVDC systems.An optimized control strategy is proposed for the typical control of tap changers in UHVDC systems.For the sending converter station,the proposed strategy suggests appropriate expansion of the triggering angle deadband and adjustment of the tap changer before converter deblocking.For a receiving converter station based on alfa-max inverter control,dynamic DC voltage control and corresponding upgrading is proposed.For a receiving converter station based on constant DC voltage control,the proposed strategy suggests expanding the extinguishing angle deadband appropriately and regulating the tap changer before converter deblocking.The presented optimized control strategy of tap changers is theoretically concise and requires minimal modifications to existing control and protection systems,making it easily applicable.Theoretical analysis results,real-time simulations,and on-site operational data validate the efficacy of the proposed strategy,showing significant reductions in tap changer actions and promising prospects for UHVDC applications.