基于积分法和差分法的电力系统短路电流直流分量特征参数计算  

Calculation of DC Component Characteristic Parameters of Power System Short-circuit Current Based on Integral and Difference Method

作　　者：王蒙 张文朝 高享想[3] 曹生顺 汪莹 WANG Meng;ZHANG Wenchao;GAO Xiangxiang;CAO Shengshun;WANG Ying(Northwest Branch of the State Grid Corporation of China,Xi'an 710000,China;Beijing Kedong Electric Power Control System Co.,Ltd.,Beijing 100089,China;Xi'an High Voltage Apparatus Research Institute,Co.,Ltd.,Xi'an 710077,China)

机构地区：[1]国家电网公司西北分部,西安710000 [2]北京科东电力控制系统有限公司,北京100089 [3]西安高压电器研究院有限责任公司,西安710077

出　　处：《高压电器》2018年第12期268-273,280,共7页High Voltage Apparatus

摘　　要：近些年随着电网中直流时间常数的增大,导致短路电流中直流分量衰减速度很慢,超出高压交流断路器在设定时间内开断短路故障的能力。因此,直流时间常数的计算与评估对电网的优化设计和安全运行尤为重要。文中通过构造函数提出了积分法、差分法、组合法3种计算短路电流中直流分量特征参数(初始值I0和时间常数τ)的方法,并应用积分法、差分法、组合法分别对含有三次、五次谐波的3种典型的短路电流波形进行直流分量特征参数计算。研究结果表明:积分法、差分法、组合法对理想的短路电流波形均能够零误差的计算直流分量的初始值和时间常数;叠加高斯白噪声信号后,3种算法的计算精度依次为积分法、组合法、差分法,且3种计算方法对叠加信噪比60 dB高斯白噪声信号的计算结果要优于叠加信噪比30 dB高斯白噪声信号。最后,应用积分法对电网实测的短路电流直流分量进行了计算,该方法为电网短路电流直流分量特征参数随时间变化时的参数计算提供了一种新的解决方法。In recent years,with the increase of DC time constant of power grid,which leads to DC component of short circuit decayed low and exceeded the interruption capability of circuit-breakers in the set time.Therefore,the calculation and evaluation of DC time constant is especially important for the optimal design and safe operation of power grid.In this paper,the integral method,difference method and combination method for calculating the char- acteristic parameters of DC component of short circuit current with three times and five times harmonic have been proposed.The results show that integral method,difference method and combination method can calculate the char- acteristic parameters of DC component with zero error for ideal short circuit current waveform.After superposing Gauss white noise signal the calculation precision of three algorithms is integral method,combination method and difference method in turn.What's more,add the 60dB Gaussian white noise calculation result is better than 30dB Gaussian white noise.Furthermore,the DC component of short-circuit current measured in power system is calculat- ed by integrating method,it is provided a new solution to calculated the characteristic parameters of DC component when varying to time.

关 键 词：直流分量 时间常数 积分法 差分法 组合法 

分 类 号：TM744[电气工程—电力系统及自动化]