摘要
针对传统静电电位测量方法的缺点提出了基于复合调制的测量方法。采用电压发生器产生辅助交直流合成电压施加到静电体接地端,辅助交流电压的频率与振动电极的振动频率不相等。通过锁相检测流过振动电极且频率为电极振动频率的电流分量幅值及其随辅助直流电压变化的方向,检测频率为振动频率与辅助交流电压频率之和的电流分量幅值,计算得到静电电位的大小及其极性。理论和实验结果表明,所提出的方法只需要较低的辅助调制电压就可以实现静电电位的精确测量和极性判别,并且测量结果与电极的尺寸、安装参数、振幅等误差以及测量回路分布电容无关。
In view of the disadvantages of the traditional electrostatic potential measurements, a measuring method based on complex modulation is proposed： The auxiliary AC and DC synthesized voltage generated by voltage generator is applied to the grounding end of the electrostatic body, with the auxiliary AC voltage having a frequency differing from the vibration frequency of the vibrating electrode. The electrostatic potential and its polarity are derived according to the amplitude of the current component through the vibrating electrode with the frequency being equal to the vibration frequency, its variation direction as a function of the auxiliary DC voltage variation, and the amplitude of the current component with the frequency being equal to the sum of the vibration frequency and the auxiliary AC voltage frequency, which are obtained by using the phase lock-in detection technique. The theoretical analysis and the experimental results show that the proposed method can provide accurate measurement for the electrostatic potential and its polarity under a relatively low auxiliary modulation voltage, while the measurement results are independent on the size and installation of the electrode, the amplitude of the vibration, and the distributed capacitance in the measuring circuit.
出处
《电测与仪表》
北大核心
2013年第3期45-49,共5页
Electrical Measurement & Instrumentation
关键词
静电测量
振动电容
调制
electrostatic measurement, vibration capacitor, modulation
