| In recent years,with the development of ultra-high voltage long-distance power transmission technology and the access of various impact loads in the power grid,the problem of voltage fluctuations in the power grid has become increasingly serious.The use of on-load voltage regulators in the distribution network is one of the most effective ways to stabilize voltage.The on-load voltage regulation technology realizes voltage regulation by changing the position of the tap.The traditional mechanical on-load tap-changer has problems such as slow switching speed,high failure rate,and easy arcing during the switching process;Although the new power electronic on-load tap-changer has a fast response speed,its manufacturing cost is high,and the output voltage harmonic content is high,which affects the power quality.Based on the above problems,this paper proposes a topological structure of a magnetic control transformer.The magnetic control transformer is composed of a magnetic saturable reactor and a transformer in series,without a mechanical transmission device.It can realize the stepless smooth adjustment of the output voltage and has the advantages of no arc in voltage regulation and high power quality.First of all,this paper analyzes the basic structure and principle of the magnetic control transformer in detail,and focuses on the electromagnetic characteristics of the magnetic saturable reactor in the magnetic control transformer.The harmonic characteristics and control characteristics of the magnetic control transformer are theoretically derived,which lays a theoretical foundation for the next simulation analysis.Secondly,the Ansys Maxwell software is used to build a two-dimensional model of the magnetic control transformer,and its working characteristics are analyzed through the co-simulation of Ansys Maxwell and Simplorer software,and the Fourier harmonic analysis of the output voltage is carried out by the Matlab/Simulink software.The simulation results show that the magnetic control transformer can continuously and smoothly adjust the output voltage,and has fast response speed,strong short-circuit capability of carrying load,and high power quality,which are consistent with the theoretical analysis.Finally,the voltage control strategy of the magnetic control transformer is researched,and the PI controller is designed to realize the output voltage control function.The simulation verifies that the controller has good control effect and meets the requirements of practical application.On this basis,a complete control system based on MSP430F149 is designed,and the hardware circuit and software program design method is given,which provides a reference for the design of the magnetic control transformer control system. |
