At present, our country power quality national standard was chiefly stipulated five quotas: frequency, harmonic and voltage deviation, three-phaseunbalance and the voltage fluctuation and flicker.
目前我国电能质量国家标准主要规定了五个指标：频率、谐波、电压偏差、三相不平衡及电压波动与闪变。
2
Three unbalanced phase loads varies randomly to lead to three phases unbalance in middle and low voltage distribution system, whi ch brings a series of problems on power grid.
在中低压配电网中，三相负荷随机变化，产生三相不平衡，从而给电网带来了一系列的问题。
3
Three unbalanced phase loads varies randomly to lead to three phases unbalance in low voltage distribution system, which brings a series of problems on power grid.