The concept of power quality includes the quality of the supplying voltage with respect to, for instance, voltage sag, imbalance, harmonic distortion, voltage fluctuation and flicker, etc.

• 质量包括电源电压的质量的能力的概念与有关，例如，电压下跌，不平衡，谐波失真，电压波动并且摇曳，等等