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中文摘要：
雷击±800kV直流输电线路时，在未造成故障的情况下，其电压行波围绕原直流量上下交替变化，电压行波在多次折反射后，由于色散最终将衰减为零。因双极直流线路间存在电磁耦合，雷击线路时的电压行波在雷击后起始的一段时间内变化一致；在雷击造成故障或线路非雷击短路的情况下，相当于故障点突然叠加故障激励源，其电压行波被突然截断，此后的变化过程类似于直流激励合闸电路的动态过程。在雷击线路故障后起始的一段时间内，故障极电压迅速衰减，而健全极电压则上升。据此构成故障选极判据。在雷击造成故障或线路短路情况下，初始电压行波对应的小波变换模极大值的特征为极性相反、数值相等。据此特征构造故障行波的识别方法。2个判据相结合以期提高可靠性。该方法的物理概念清晰，大量的EMTP暂态仿真表明，方法可靠且有效。
英文摘要：
In case of lightning stroke on ±800 kV UHVDC transmission line but not developing into fault, the voltage traveling-wave fluctuates around the original DC component value. After several refractions and reflections, it gradually declines to zero due to dispersion. Because of the electromagnetic coupling existed between bipolar two transmission lines, the variations of voltage traveling-wave on the two lines are identical in the short time after lightning stroke, Under the condition of transmission line fault caused by lightning stroke or short-circuit, a fault driving source is superposed to the one at fault point which cuts off the voltage traveling-wave suddenly, and the transient process after fault is similar to the dynamic response to the phenomena of DC source switching in, In a short fault time after lightning stroke, the voltage traveling-wave of fault pole declines quickly, while that of sound pole rises. According to above phenomenon, criterion can be formed to identify the fault pole. Under above condition, the wavelet transform modulus maximum of bipolar primary voltage traveling-wave shows that the module value is identical and the polarity is opposite. This phenomena can be another criterion to identify the traveling waveform caused by fault. Reliability of identification will be increased when these two criteria are combined together. The physical conception of this method is clear and EMTP simulation results show that the method presented in this paper is feasible and effective.
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