Electromagnetic Transient Modeling And Fast Simulation Of Soft Open Points In Active Distribution Network

With the continuous development of power electronic technologies,the structure and operation of distribution systems are changing enormously.Soft open points?SOPs?based on fully controlled power electronic devices can improve the economy,flexibility and reliability of distribution system by effective control of power flow and couple the system dynamics with more complex power electronics characteristics.Many scenarios including parameter design of SOP controller,harmonic analysis,and determination of system protection strategies are highly dependent on transient simulation results.This thesis focuses on the modeling and fast simulation algorithm of SOP and its integration into distribution systems.The main contributions are summarized as follows:1)The detailed dynamic models of SOP with different configurations are investigated,including the SOPs with two terminals and multiple terminals,and their controller with U_dcQ control,PQ control and V/f control.These models are built for analyzing and simulating the dynamics of distribution system with SOPs.2)A Krylov-based model order reduction?MOR?algorithm for transient simulation of distribution system with variable structure conditions is proposed.To simulate the detailed dynamics of SOP under different system disturbances,a novel algorithm is proposed to extend the MOR method to variable-structure system,making it applicable to the multi-scenario analysis of SOP when external system fault occurs.3)Several cases are studied to validate the SOP models and the simulation algorithm.Compared the results with different model dimensions,the reduced model can improve the simulation efficiency in acceptable errors.The simulation results validate the correctness and effectiveness of the proposed method.