Through studying the principle of dimmer and switch power supply, it was found that in some frequency points, by analyzing the phase of electric voltage and current it can tell if arc faults occur.

• 研究调光灯及开关电源的工作原理可以发现，通过分析回路中电压电流在某些频率点的相位信息，可以有效判别是否发生了故障电弧。