摘要
为提高电力系统电磁暂态计算精度,输电线路元件模拟常用分布参数,电磁暂态仿真软件中,也有与之匹配的输电线路频率相关模型。为验证ATP与PSCAD中该模型的精确度,提出一种时域仿真反推算输电线路衰减系数的方法,通过卡尔松公式计算输电线路理论衰减系数;分别建立输电线路电磁暂态仿真模型,使系统在某一频率下进行暂态仿真直至稳态,分析线路中点与末端电压波形,利用稳态参数反推算其衰减系数,比较在不同频率下与理论计算所得衰减系数的误差;通过对比输电线路参数理论计算值与仿真计算值,分析误差产生的原因。结果表明:输电线路暂态过程中,高频下的衰减系数远大于工频。随着频率的升高,输电线路参数正序、零序的衰减系数都逐渐增大,且零序表现的更为明显,在频率为50000 Hz时,其衰减系数可达到工频时的17倍;比较理论与仿真计算结果,ATP中的频率相关模型参数计算比较精确,50000 Hz时计算出衰减系数误差为0.66%,PSCAD中衰减系数误差较为明显,50000 Hz时计算出衰减系数误差为3.41%,且随着频率的增大,衰减系数误差也越来越大。究其原因,PSCAD中线路参数计算得到的电阻值偏大,其与程序中求解频变参数计算公式有关,电磁暂态仿真时需予以重视。
In order to improve the accuracy of electromagnetic transient calculation of power system,the distribution parameters are commonly used in the simulation of transmission line components.In the electromagnetic transient simulation software,there are also corresponding transmission line frequency correlation models.In order to verify the accuracy of the model in ATP and PSCAD,a method for inversely calculating the attenuation coefficient of transmission lines was proposed by time domain simulation,and the theoretical attenuation coefficient of transmission lines was calculated by Karlsson’s formula.The two software were used to establish the electromagnetic transient simulation model of the transmission line,so that the system can be simulated to the steady state at a certain frequency,the voltage waveforms at the midpoint and the end of the line were analyzed,the attenuation coefficient was inversely calculated by using the steady-state parameters,and the error of the attenuation coefficient was compared with the theoretical calculation at different frequencies.By comparing the theoretical calculation values of transmission line parameters with the simulation calculation values,the causes of errors were analyzed.The results show that the attenuation coefficient at high frequency is much greater than that at power frequency during the transient process of transmission line.With the increase of frequency,the attenuation coefficients of the transmission line parameters in positive sequence and zero sequence gradually increase,and the zero sequence is more obvious.when the frequency is 50000 Hz,the attenuation coefficient can reach 17 times that of power frequency.Comparing the theoretical and simulation results,the frequency-related model parameters in ATP are more accurate.The error of attenuation coefficient is 0.66%at 50000 Hz,and the error of attenuation coefficient in PSCAD is more obvious.The error of attenuation coefficient is 3.41%at 50000 Hz,and with the increase of frequency,the attenuation coefficient error is also increasing.The reason is that the resistance value calculated by line parameters in PSCAD is too large,which is related to the calculation formula of frequency-dependent parameters in the program.Attention should be paid to electromagnetic transient simulation.
作者
李磊
马宪民
LI Lei;MA Xianmin(College of Electrical and Control Engineering,Xi’an University of Science and Technology,Xi’an 710054,China)
出处
《西安科技大学学报》
CAS
北大核心
2023年第6期1219-1226,共8页
Journal of Xi’an University of Science and Technology
基金
国家自然科学基金项目(52177056)。
关键词
输电线路
分布参数
反推算
衰减系数
频变参数
transmission line
distributed parameter element
inverse estimation
attenuation coefficient
frequency-varying parameter
