定子绕组对地电容作为发电机的一项重要参数,其准确测量可为发电机定子接地保护方案的制定提供重要依据。在此背景下,对发电机定子绕组故障分支进行分割,并对电压互感器内部结构进行研究,提出一种采用电流信号注入形式的发电机定子绕组对地电容实时测量方法。首先,通过从电压互感器低压开口三角形侧注入电流信号,流经电压互感器高压侧及绕组对地电容构成回路;然后,分别测量电压互感器低压开口三角形侧电压和低压星型侧电压;最后,基于构成回路的简化电路以及注入的电流信号、测得的电压信号计算出定子绕组对地电容大小。 该法避免了电压互感器短路阻抗对测量结果的影响,经 PSCAD/EMTDC仿真结果和实验结果表明,该测量方法过程安全、接线简单、结果准确。
The stator winding-to-ground capacitor is an important parameter of generator, and its accurate measurement can provide important basis for the stator grounding protection scheme. On the background, the fault branch of generator stator winding is divided, and the internal structure of voltage transformer is studied. Then, a real-time measurement method for the stator winding to ground of generator based on the injected current signal is proposed. Firstly, the current signal is injected from the low-voltage triangle side of voltage transformer for the generator and flows through the high-voltage side of the voltage transformer and the capacitance of the winding to ground. Secondly, the low-voltage triangle-side voltage and the low-voltage star-side voltage of the voltage transformer is measured respectively. The simplified circuit and the injected current signal and the measured voltage signal calculate the stator winding capacitance to ground. This method avoids the influence of the short-circuit impedance of voltage transformer on the measurement results. The PSCAD/EMTDC simulation and experimental results show that the measurement method is safe in process, simple in wiring, and accurate in results.
黄路明,熊锋,巫晓云,陈豪威.基于注入信号的发电机定子对地电容测量方法[J].电力科学与技术学报,2021,(2):83-88. Huang Luming, Xiong Feng, Wu Xiaoyun, Chen Haowei. Real-time measurement scheme of large-scale generator stator winding to ground capacitance[J]. JOURNAL OF EIECTRIC POWER SCIENCE AND TECHNOLOGY,2021,(2):83-88.复制