Research On Technology Of Symmetrical Dual-core Phase Shifter Applied To Power Flow Regulation In Power Grid

The phase-shifting transformer can redistribute the active power between the lines by changing the phase shift or amplitude of the voltage connected to the line windings,thereby controlling the distribution of power flow,fully tapping the potential of the existing transmission lines,and improving the stability of the power system It is very necessary for research on related technologies,such as sex,economy,and so on.This paper takes the 110 k V transmission line ice melting project of a HW-SP substation in a certain area of Guizhou as the research background,takes the symmetrical double-core phase-shifting transformer as the research object,and synthesizes some of the problems encountered in the research process and the corresponding solutions.,Carried out the following research work:Firstly,the application status of phase-shifting transformers at home and abroad is summarized,the model improvement of phase-shifting transformers in calculation is analyzed,and the research progress of phase-shifting transformers in terms of optimal power flow and short-circuit current limitation in recent years is explained.The application of renewable energy and system interconnection is explained,the combination of phase-shifting transformers and other electrical components are introduced,and the basic principles of phase-shifting transformers are analyzed,and the types of phase-shifting transformers and their adjustment methods are summarized..Secondly,integrating the topology structure of the actual phase-shifting transformer and the existing problems in simulation modeling,the modeling method of the two-core symmetrical phaseshifting transformer is improved,and the positive sequence and negative sequence equivalent models of the symmetrical two-core phase-shifting transformer are derived.And the calculation method of the primary and secondary leakage impedance of the series transformer and the excitation transformer,and the simulation experiment of the calculation method through MATLAB/Simulink verifies the feasibility and accuracy of the proposed calculation method,and makes the simulation model correspond to the actual parameters.Close to practical application.Then,the principle of phase-shifting transformer used for line ice melting is analyzed,and the basic parameters and connection methods of phase-shifting transformer are designed based on the actual situation of related projects.The 110 k V transmission line of HW-SP substation in a certain area of Guizhou was modeled by MATLAB/Simulink software,and the phase-shifting transformer was used for the demonstration of ice melting of the transmission line in this area.Finally,on the basis of deriving the zero-sequence model of the symmetrical double-core phase-shifting transformer,a pilot directional protection method based on the zero-sequence fault component is applied.The principle is mathematically analyzed,and the electromagnetic transient software PSCAD is used for simulation verification.The results show that the protection principle can clearly distinguish the internal and external ground faults and the turn-to-turn and turn-toground short-circuit faults in the protection zone.The algorithm judgment principle is simple and has certain characteristics.Theoretical and practical value.