Prepared bya TaskForceoftheDcField& IonsWorkingGroup IEEECorona& FieldEffectsSubcommittee

£gQDUCIIN Intransmitting largeblocksofelectric power over longdistances, highvoltagedctransmission linesmaybemoreeconomically attractive thanhigh voltageac lines.Toproperly evaluate thebenefits ofdcoverac, however, consideration hastobegiven to all aspects ofthetransmission lineperformance. To moreeffectively address thoseaspectsrelatedto corona,electric fieldsandmagnetic fields, theRadio Noiseand CoronaSubcommittee was reorganized, in 1978,intotheCoronaand FieldEffectsSubcommittee. At thattimea newWorkingGroupwas formedto specifically addressthe subjectof the electric fieldsandioneffectsofdctransmission lines.One ofthefirsttasksestablished bythenewDcFieldand Ions WorkingGroupwas a reviewof existing instrumentation and techniques for measuringdc electricfield and ion relatedquantities. To complement thisreview, theWorking Groupsponsored an experimental fieldprogramwhosepurposewas to comparetheperformance of variousinstruments for measuring electricfieldandioncurrent.Thefield program, heldatProject UHVinLenox,Massachusetts, duringSeptember 5-7,1979,was attendedby 20 representatives from utilities,manufacturing companies, universities, and government agencies. Subsequently, a TaskForcewas formedtoanalyzethe dataarisingfrom the program,andtopublish the findings intheformofanIEEECommittee Report.