The main contents of power energy include frequency deviation, voltage deviation, voltage fluctuation and flicker, voltage unbalance, temporary or transient over-voltage, wave distortion, voltage dips and interruption, power supply reliability and so on.

• 电能质量的内容包括频率偏差、电压偏差、电压波动与闪变、三相不平衡、暂时或瞬时过电压、波形畸变、电压暂降与短时中断以及供电连续性等。