【摘要】 量测配置薄弱一直是困扰配电网状态估计精度的重要原因。台区智能融合终端的广泛应用丰富了量测配置，并使配电网状态估计范围延伸到配电变压器低压侧，客观上对配电变压器参数的准确性提出了更高的要求。配电变压器数量多，参数维护工作量大，参数准确性目前仍难以得到有效保证，变比参数错误是导致配电网状态估计精度低的关键因素。利用配电变压器普遍采用无载调压抽头、变比变化频率较低的特点，提出考虑配电变压器变比误差的配电网多断面联合状态估计方法。通过建立直角坐标系下基于二次型的配电网多断面联合状态估计模型，并采用正交变换法求解，实现对配电变压器变比的准确估计。IEEE 33节点修正系统及某实际配电网的算例分析结果表明，所提方法能够对配电变压器变比给出较为准确的估计，有助于及时发现并修正变比参数错误，减轻参数维护工作量，提升配电网状态估计精度。更多还原

【Abstract】 The weakness of measurement configuration is always an important reason plaguing the accuracy of distribution network state estimation(DSE). The widespread application of intelligent fusion terminals enriches measurement configuration of the distribution network, which extends the range of DSE to the lower side of distribution transformers(DTs) and puts forward higher requirements for the accuracy of DT parameters. The large quantity of DTs results in significant maintenance workload and the current difficulty in ensuring parameter accuracy, with tap ratio errors being a key factor leading to low accuracy of DSE. According to the characteristics of the widespread use of no-load tap changers and the low frequency of tap ratio variations in DTs, this paper proposes a DSE method with multi-scan measurements considering tap ratio errors of DTs. By establishing a distribution network state estimation with multi-scan measurement model based on quadratic forms in a rectangular coordinate system and solving it using orthogonal transformation methods, the accurate estimation of tap ratios of DTs can be achieved. The DSE results of the modified IEEE 33 system and an actual distribution network show that the proposed method can give accurate estimation of transformer tap ratios, which helps to detect and correct the tap ratio errors in time, reduces the parameter maintenance workload and improves the accuracy of DSE.更多还原