This added voltage is mainly powerlinefrequency and its effect on the voltmeter reading will depend upon the normal-mode rejection capability of the meter.
这个相加的电压主要为电源频率的信号，其对于电压表读数的影响决定于电压表的串模抑制能力。
2
On line predicting obtaining power system post disturbances steady frequency is beneficial for frequency stability assessment and emergency control.
在线预测系统扰动后的稳态频率，有利于扰动后系统频率稳定性评估和紧急控制。
3
Orthogonal Multi-Carrier Modulation(OMCM) is adopted to overcome the frequency selectivity and time variation of low-voltage powerline channel.