It covers five aspects: supply voltage tolerance, utility harmonic, three-phase voltage unbalance, power system frequency tolerance, voltage fluctuation and flicker.
它涵盖五个方面：供电电压允许偏差、公用电网谐波、三相电压不平衡度、电力系统频率允许偏差、电压允许波动和闪变。
At present, our country power quality national standard was chiefly stipulated five quotas: frequency, harmonic and voltage deviation, three-phase unbalance 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。
Several issues of power quality are presented, including harmonics, reactive power, three phase unbalance, large difference between peak load and vale load, voltage disturbance and so on.
第一章简单介绍了目前电网存在的几种问题，包括谐波问题、无功问题、三相不平衡问题、用电峰谷差过大的问题以及电压异常、断电问题等；
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。
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.
在电网中，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。
Voltage unbalance of three phase ac distribution systems adversely affects power customers.
配电系统三相电压的不对称会对用户造成一系列不利影响。
Based on this requirement, this paper introduced the theory of power quality monitoring, include RMS of voltage and current, power, three-phase unbalance, harmonic and flicker.
在此基础上研究了电能质量监测理论，详细介绍了电压电流有效值、功率、三相不平衡度、谐波和闪变的数字测量方法。
Based on this requirement, this paper introduced the theory of power quality monitoring, include RMS of voltage and current, power, three-phase unbalance, harmonic and flicker.
在此基础上研究了电能质量监测理论，详细介绍了电压电流有效值、功率、三相不平衡度、谐波和闪变的数字测量方法。
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