基于量测数据的外部电网在线等值实用方法

如何进行准确的外部电网等值是一个经久不衰的研究课题。文中提出了基于量测数据的外部电网在线等值实用方法。该方法首先构建了外部电网等值网络,该网络包括边界节点间的耦合支路,每一边界节点通过支路与外部电网等值电源相连。进而,构建了基于数据采集与监控(SCADA)在线量测数据的等值网络参数优化求解模型,该模型以边界节点的量测值与计算值的失配量的和最小为目标,以所有等值支路的参数在合理范围内为约束。为保证等值参数估计的稳定性和收敛性,提出2个策略:一是基于最大及最小运行方式下的Ward等值网络相应等值支路的阻抗值作为在线等值网络参数范围;二是基于历史数据获取补充量测,避免要求内部电网进行非计划开合操作以及由此带来的一系列问题。算例证明了所提模型及算法的有效性和正确性。

Practical Online Equivalent Method for External Grid Based on Measurement Data

How to conduct the accurate equivalency of external grids has been a hot topic for many years. A practical online equivalent method for external grid based on measurement data is proposed. Firstly, an equivalent network for the external grid is built, which includes coupling branches between boundary nodes, and each boundary node is connected to an equivalent power source of the external grid through a branch. Furthermore, a parameter optimization solution model for the equivalent network is constructed based on online measurement data obtained by supervisory control and data acquisition (SCADA). The model takes the minimum sum of the mismatch between the measured value and the calculated value of the boundary node as the objective, and the parameters of all the equivalent branches within the reasonable range as the constraints. In order to ensure the stability and convergence of the equivalent parameter estimation, two strategies are proposed. One is to take the impedance value of the equivalent branch of Ward equivalent network in the maximum and minimum operation modes as the online equivalent network parameter range. The other is to obtain supplementary measurements based on historical data, thus avoiding the requirement of unplanned opening and closing operations of the internal grid and a series of following problems. Example results demonstrate the validity and effectiveness of the proposed model and method.