借助输电线路数据采集与监控(SCADA)系统量测的信息,建立输电线路温度及热平衡微分方程参数的连续估计,进行输电线路动态热定值(DTR)的软实现。首先,基于载流导体电阻与温度变化间明确的物理解析规律,利用输电线路两端量测建立输电线路电阻的扩展估计模型,从而间接得到输电线路温度;其次,考虑电阻变化的马尔可夫特性,利用相邻时刻的先验信息对估计电阻值进行修正,以提高估计精度;最后,利用已知输电线路温度序列,采用渐消递推最小二乘估计实现简化热平衡方程参数的估计,从而通过载流等电气量测间接实现了硬DTR设备的功能。以山东烟台电网实测数据验证了方法的可行性。
Based on SCADA information,the soft realization idea for dynamic thermal rating(DTR)is presented,which establishes continuous estimation model of transmission line temperature and parameters of its heat balance differential equation(HBE).Firstly,based on the explicit analytic physical rules for relationship between conductor's resistance and temperature,an extended estimation model of line resistance is established with measurements of the line,then the transmission line's temperature can be obtained indirectly;Secondly,considering resistance change Markov property,the adjacent time priori information of resistance is used to modify the estimation result so as to improve its accuracy;Finally,with the known transmission line temperature series,a fading-memory recursive least square method is used to estimate parameters of reduced HBE,hence,the function of DTR hardware is realized indirectly through electric measurement of transmission line.The feasibility of the proposed method is verified by the tested data from Yantai grid of Shandong province.