考虑换流器控制特性的交直流混联微电网状态估计

State Estimation of AC-DC Hybrid Microgrid Considering Inverter Control Characteristics

交直流混联微电网是分布式发电(distributed generation,DG)装置并网的良好解决方式,因此,含DG的交直流混联微电网状态估计研究具有现实意义。针对换流器控制特性多样化及直流网络接入,该文提出适用于多种运行模式的交直流混联微电网状态估计模型。首先,针对微电网的孤岛运行特性,建立DG的Droop型节点模型。接着,根据交直流混联微电网状态估计的特点,配置相应的伪量测,以提高系统可观测性;同时采用了支路电流幅值量测转换法,以减少雅可比矩阵的求解难度。最后,采用最小二乘估计求解所提出的交直流混联微电网状态估计模型。通过IEEE13节点算例进行验证,结果表明,所提模型能够适用于并网和孤岛两种运行方式,具有良好的工程实用价值。

The AC-DC hybrid microgrid is the good solution for distributed generation（ DG） paralleling in grid.Therefore,it is of great value to study the state estimation of AC-DC hybrid microgrid with DG. According to the control characteristic diversification of inverter and the integration of DC grid,this paper proposes a novel state estimation algorithm for the AC-DC hybrid microgrid considering operating status. Firstly,we establish the Droop-type node model of DG based on the islanded operating characteristics of microgrid. Furthermore,we formulate the appropriate pseudo-measurements to improve the system observability,according to the state estimation features of the AC-DC hybrid microgrid. M eanwhile,we use the branch current amplitude measurement conversion to reduce the difficulty of solving Jacobian matrix. Finally,we adopt the least square estimation to solve the proposed state estimation model of the AC-DC hybrid microgrid. The proposed models on grid-connected and islanded operation modes are tested on the modified IEEE-13 bus distribution system,whose results demonstrate the effectiveness of the proposed model in engineering applications.