补偿电网阻尼率及脱谐度的分析

Analysis of damping rate and out-of-resonance degree of compensation network

阻尼率和脱谐度是补偿电网的两个重要参数,针对运行中出现的相关问题,从中性点位移电压、三相电压不平衡度以及残流的有功分量、无功分量等方面,分析了阻尼率和脱谐度对补偿电网运行特性的影响,给出了合理配置阻尼率和脱谐度的公式,分析认为,采用非线性电阻将增大残流的有功分量,不利于电弧的熄灭;在保证残流小于规程允许范围内的前提下,适当增大脱谐度,可改善三相电压不平衡度,有利于补偿电网的运行。应用这些研究成果也解决了实际运行中出现的一些相关问题。

Damping rate and out-of-resonance degree are two important parameters of compensation network. To solve the relevant problems encountered in operation, the effects of damping rate and out-of-resonance degree on the operation characteristic of the compensation network were analyzed from the aspects of neutral-point displacement voltage, degree of unbalance of the voltages on three phases and the active and reactive components of residual current. The formulas for properly configuring the damping rate and out-of-resonance degree were given. After analyzing it is considered that the adoption of the non-linear resistance will result in the increase of the active component of the residual current which is disadvantageous to the arc suppression; in the prerequisite that the residual current is kept below the limitation specified by the code, appropriate increase in out-of-resonance degree will improve the degree of unbalance of the voltages on three phases and is beneficial to the compensation network operation. Some relevant problems encountered in actual operation can be solved through applying these research achievements.