超高压交流线路对平行架设特高压直流线路的电磁感应

摘要

交流输电线路与特高压直流输电线路平行架设时，通过电磁耦合交流线路会在特高压直流线路上感应出工频交流分量。感应产生的工频电流，经过换流器后会产生直流分量。此直流分量流经换流变压器，会导致换流变压器偏磁。采用EMTDC程序建立了交/直流输电系统仿真模型，对交流输电线路对平行架设的特高压直流输电线路产生的电磁感应影响进行仿真研究，分析了交/直流线路平行架设长度、接近距离、土壤电阻率、杆塔接地电阻等因素对特高压直流线路的工频电磁感应影响。另外，对比分析了超高压紧凑型线路、常规型线路分别与特高压直流线路平行架设时特高压直流线路上的工频感应电压、电流和直流偏磁电流。%When AC transmission line is in parallel with UHVDC line , it may cause electromagnetic influence upon UHVDC transmission line and the power -frequency AC component will occur along the UHVDC transmission line .The power -fre-quency AC current will be transformed into DC current by current converter .When flowing into converter transformer , DC cur-rent can cause magnetic bias .Based on EMTDC software , the simulation model of AC/DC transmission lines is established . The electromagnetic induction influence of AC transmission line on parallelly erected UHVDC transmission line is studied .The factors that affect the influence of electromagnetic induction on UHVDC transmission line are analyzed such as parallel erection length, adjacent distance, soil resistivity and tower grounding resistance .The power -frequency induced voltage , induced current and DC bias current in UHVDC lines which are in parallel with EHVAC compact line or EHVAC conventional line are compared and analyzed .