地电流干扰系统级抑制方法及机理探究

The Exploratory Development and Mechanism Analysis of Systematic Suppression Methods on Ground Current

电力电子设备以不同的馈入方式将大量干扰信号引入到独立系统壳体上,形成复杂的地电流,在不同接地系统之间通过共地耦合产生共模干扰。此处试图探索从整体上消除或减少馈入壳体的地电流,进而抑制传统屏蔽、滤波等措施难以解决的低频共模干扰。基于不控三相整流桥馈入钢板地电流回路,研究了地电流馈入机理及特性,探究了增大直流母线屏蔽层电感和在钢板两端并联LC谐振电路两种系统级抑制地电流干扰的方法,分析了其基本原理、抑制效果及失效机理。

Various power-electronic equipments inject raff interference into the steel plane via multiform feed-in pattens in isolated systems,which causes complex ground current.The common-mode interference is generated between the grounding subsystems via common ground coupling.The development on how to holistically eliminate or decrease the current injected into the plane is seeked,in order to suppress the low-frequency common-mode interference which is invalidation with shielding and filtering.Based on the ground current loop feed-in by non-controlled three-phase rectifier,the feed mechansim and characteristic of ground current are investigated,and two approaches on systematic sup-pression are explored,include enlarging the shielding inductance and paralleling LC resonance circuit.Also the fundamental,suppression effect and failure mechanism are analysed.