Analysis Of Electromagnetic Interference In Extra High Voltage Flexible DC Converter Station And Research On Immunity Of PCB Board

With the vigrous development of the domestic HVDC-flexible project,extra high voltage DC-flexible converter station,especially the electromagnetic environment inside the valve hall has gradually get people's attention.Therefore,it is necessary to measure the electromagnetic environment of extra high voltage HVDC-flexible converter station.Electromagnetic disturbance measurements of this article is divided into three levels,by participating in a laboratory of the relevant laboratory test,the radiated electric field generated by the steady operation of a single IGBT submodule was obtained.And when the valve module composed of a plurality of submodules separately electrified with different operating conditions,the radiated electric field near the PCB board and copper bar mounted on the valve module was measured.Finally,with the domestic has been put into operation extra high voltage DC-flexible project,a large number of measurements have been made on the radiated electric field of multiple measuring points inside and outside the valve hall of extra high voltage DC-flexible converter station.Among them,the electric field distribution inside and outside the valve hall is analyzed when the valve tower of converter station is electrified.Because the PCB board installed in the valve,the electromagnetic disturbance generated by the valve will affect the working status of the PCB board,the immunity characteristics of PCB board cannot be ignored.According to the design of PCB board,an equivalent simulation model of PCB board is established,by applying near-field harassment,the electric field intensity distribution under certain special frequencies on the PCB is obtained,in this way,we know the sensitive area with high electric field intensity on the PCB board.And through the time domain and frequency domain simulation respectively solves the sensitive voltage peak of these sensitive areas and the corresponding sensitive frequency.By applying the far-field planar wave disturbance,the induced voltage and the sensitive frequency at some key ports on the PCB board are obtained by using the simulation in time domain and frequency domain.Then derives the tolerable electric field strength at the port based on the peak value of the induced voltage at the critical port.