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电网参数准确性对状态估计结果存在较大影响.基于电热关联理论,考虑线路温度对电阻参数的修正,将线路热平衡方程同状态估计模型相结合,提出一种计及线路温度的两步状态估计模型与算法.该算法利用内层循环修正电气量,外层循环修正线路温度和电阻参数,能够获得精确的电气量和线路温度值.进而将线路热平衡方程作为伪量测量,将线路温度引入状态量中,建立计及线路温度的联合状态估计模型,详细推导了 SCADA 及相量测量单元(phasor measurement unit,PMU)量测量对于线路温度的偏导数,并对伪量测量予以较大权重来求解.最后采用IEEE14、39和118节点算例验证了算法的有效性和效率.结果表明,所述方法能有效降低状态估计误差.“,”The accuracy of transmission line parameters has a great influence on power system state estimation results. Based on the theory of electro-thermal coupling, a two-step state estimation algorithm was proposed by integrating the heat balance equation into the conventional state estimation model. The correction of the line resistance according to line temperature was considered in the proposed algorithm. The algorithm used the inner loop to modify electrical quantity, and the outer loop to correct line temperature and resistance, which can achieve more precise estimation results of electrical quantity and line temperatures. Furthermore, heat balance equation was introduced as the pseudo measurement and line temperature was introduced into the state vector. Joint state estimation model considering line temperature was established. Partial deviation of SCADA and PMU measurements to line temperature was derived and pseudo measurements were solved with a larger weight. The validity and efficiency of the proposed algorithm are verified by IEEE 14-bus, 39-bus and 118-bus case. The simulation results show that the estimation error is obviously decreased with the proposed model.