直流输电系统发生故障时，逆变侧保护动作后投入旁通对有助于快速停运直流输电系统、隔离故障。结合运行实例和仿真案例，举例说明了投旁通对的作用，探讨了投旁通对需注意的一些问题，如某些故障情况下需禁投旁通对、某些故障情况下投旁通对时应经选相，以及通信系统故障情况下投入旁通对可能带来的不良影响等。

When HVDC system faults, the bypass of converter initiated by the action of inverter HVDC protection will help to stop the HVDC system and isolate the faults quickly. Based on some operational and simulation cases, the paper describes the function of converter bypass and discusses some issues that need to be cautioned when converter bypass is used, such as the faults that prohibit the use of bypass, the faults that need the phase selection before use of bypass, and the negative influence of bypass as the telecom system faults.