基于改进增广节点方程的柔性互联配电网统一潮流计算方法

Unified Power Flow Calculation Method of Flexible Interconnected Distribution Network Based on Modified Augmented Nodal Equation

未来柔性配电网中的直流环节可能以大量、分散的变流器形式与交流电网耦合,建立统一联立的计算模型对系统准确、高效求解将更具适用性。提出了一种基于改进增广节点方程的柔性配电网潮流分析建模方法。首先,建立了基于改进增广节点方程的交流和直流电网的网络模型,以及各类型节点的潮流约束。然后,考虑了作为耦合环节的换流器及智能软开关等包含多种控制模式的电力电子设备模型,形成了柔性配电网潮流计算的改进增广节点方程,并采用牛顿-拉夫逊法实现了对模型的求解。最后,通过改进的IEEE 123节点柔性配电网算例验证了所提算法能够有效实现对电力电子化柔性配电网的求解,并适用于包含多种运行模式场景下的系统时序潮流计算。

The DC links might be coupled with AC power grids in the form of a large number of dispersive converters in the future flexible distribution network.It will be more applicable to establish a unified and simultaneous power flow model for accurate and effective solution of the system.A power flow calculation method for flexible distribution networks based on modified augmented nodal equations is proposed.Firstly,the network models of AC and DC power grids and the power flow constraints of nodes with different types are established.Secondly,the electronic equipment models of multiple modes including converters and soft open points as coupling links are considered.Finally,the modified augmented nodal equation of power flow calculation in the flexible distribution network is formed,and the Newton-Raphson method is used to solve the model.The effectiveness of proposed method is verified on the modified IEEE 123-bus flexible distribution network.The proposed method is appropriate for the time-series power flow calculation in multiple operation modes.