基于积分等值变换的电容式电压互感器暂态误差校正方法  

An Integral Equivalent Transformation Based Method for Capacitor Voltage Transformer (CVT) Transient Error Correction

作　　者：许明[1] 高厚磊[1] 邹贵彬[1] 刘洪正[2] 杨荣华[2] 

机构地区：[1]山东大学电气工程学院,山东省济南市250061 [2]山东电力集团公司超高压公司,山东省济南市250021

出　　处：《电力系统自动化》2011年第1期71-76,共6页Automation of Electric Power Systems

基　　金：国家自然科学基金资助项目(50777040);山东电力集团科技项目(2009024)~~

摘　　要：电容式电压互感器(CVT)的暂态传变误差有可能导致继电保护装置的不正确动作。为解决该问题,提出了一种基于积分等值变换的CVT暂态误差校正方法。利用梯形积分等值变换,将CVT高阶等值电路转化为t时刻仅包含电流源、电阻和输入电压源的直流电路,然后建立其节点电压方程,只需求解简单的线性方程组就能够由采集到的CVT二次电压精确地计算出一次电压。通过正常分量与故障分量的分解来解决算法的初始值问题;利用数字低通滤波器来抑制高频干扰信号对算法的影响。仿真结果证明了该方法的准确性和有效性。The transient transmission error of capacitor voltage transformer （CVT） may cause malfunction of protection relays. To solve this problem, an integral equivalent transformation based method for CVT transient error corrections is proposed. Using trapezoidal integral equivalent transformation, the high-order equivalent circuit of CVT can be transformed into a simple DC circuit just containing DC current sources, resistors and a DC voltage source. Then the nodal voltage equations of the circuit can be established. By solving these simple linear equations, CVT＇s primary side voltage can be calculated accurately using its secondary side voltage collected. The decomposition of normal component and fault component is used to solve the initial value problem of the algorithm. A digital low-pass filter is used to remove the high-frequency interference signals. Simulation results testified the accuracy and effectiveness of the correcting method.

关 键 词：电容式电压互感器 暂态误差 误差校正 积分等值变换 故障分量 数字滤波 

分 类 号：TM451[电气工程—电器]