An Observer-Based Composite Identifier for Online Estimation of the Thevenin Equivalent Parameters of a Power System
An Observer-Based Composite Identifier for Online Estimation of the Thevenin Equivalent Parameters of a Power System
复制标题
DOI：
10.48550/arxiv.2203.07273
复制
发表时间：
2022-03
期刊：
影响因子：
--
通讯作者：
Daniele Zonetti;R. Ortega;Rafael Cisneros;A. Bobtsov;F. Mancilla–David;O. Gomis‐Bellmunt
中科院分区：
文献类型：
--
作者：
Daniele Zonetti;R. Ortega;Rafael Cisneros;A. Bobtsov;F. Mancilla–David;O. Gomis‐Bellmunt
我们考虑从与电力电子转换器的公共耦合点来看捕获电网动态的戴维南等效电路，并提出了相应电路参数在线识别问题的解决方案。为此，我们首先在传统的 abc 坐标中推导线性回归模型，不幸的是，该模型严重缺乏可识别性。尽管如此，我们设计了一种基于有界观察者的复合标识符，仅需要局部测量和电网频率知识，就能确保参数估计误差的全局有界性以及收敛到实际上很小的残差集。进一步提供了在网格主要是感性的情况下保证这些误差指数收敛到零的扩展。所提出的标识符包含传统的梯度下降算法，其性能通过详细的计算机模拟进行了说明。
We consider a Thévenin equivalent circuit capturing the dynamics of a power grid as seen from the point of common coupling with a power electronic converter and propose a solution to the problem of online identification of the corresponding circuit parameters. For this purpose, we first derive a linear regression model in the conventional abc coordinates that, unfortunately, suffers from severe lack of identifiability properties. In spite of this fact, we design a bounded observer‐based composite identifier that, requiring only local measurements and knowledge of the grid frequency, ensures global boundedness of the parameters estimation error and convergence to a practically small residual set. An extension that guarantees exponential convergence of these errors to zero, in the case that the grid is dominantly inductive, is further provided. The performance of the proposed identifier, which subsumes a conventional gradient descent algorithm, is illustrated via detailed computer simulations.