高压直流输电换流站作业环境合成电场强度分析

Total electric field intensity in workplace of high-voltage direct current converter stations

[背景]高压直流输电线路的换流站会产生特殊的合成电场,目前较少从职业卫生角度对换流站内作业环境的合成电场进行调查。[目的]了解换流站作业环境合成电场强度现状。[方法]采用立意抽样方法,用已校准的HDEM-1直流合成场强检测系统,依据DL/T 1089—2008《直流换流站与线路合成场强、离子流密度测量方法》对东南地区和西南地区6条直流线路12个换流站合成电场进行检测,依据DL/T 275—2012《±800 kV特高压直流换流站电磁环境限值》、美国工业卫生师协会(ACGIH)和国际非电离辐射防护委员会(ICNIRP)推荐的职业接触限值进行评价。[结果]本次共检测615个测点的合成电场强度,测量值为0.05~37.05 kV·m^(−1),M值为10.45 kV·m^(−1)。其中39个(占6.3%)测点合成电场≥25 kV·m^(−1),超过ACGIH和ICNIRP的标准,12个(占2.0%)测点合成电场≥30 kV·m^(−1),超过DL/T 275—2012的限值。中性极区域分别与正极区域、负极区域合成电场强度结果及≥25 kV·m^(−1)的超标率比较,差异均有统计学意义(P<0.01),负极区域合成电场≥30 kV·m^(−1)的率高于正极区域(P<0.01)。不同电压等级、不同海拔高度换流站合成电场强度结果各进行比较,差异均无统计学意义(P>0.05);不同电压等级、不同海拔高度换流站合成电场≥25 kV·m^(−1)和≥30 kV·m^(−1)的率分别比较,差异均无统计学意义(P>0.05)。[结论]换流站部分作业环境合成电场超过标准,作业人员可能短时接触较高强度的合成电场。

[Background]The converter stations of high-voltage direct current(HVDC)transmission lines generate special total electric fields.At present,few investigations have been conducted on total electric fields in the workplace of converter stations from an perspective of occupational health.[Objective]To understand the current situation of total electric field strength in the workplace of converter stations.[Methods]Using purposive sampling,a calibrated HDEM-1 direct current(DC)total electric field strength measurement system was used to measure the total electric fields of 12 converter stations serving 6 DC lines in Southeast and Southwest China according to the Measurement method for total electric field strength and ion current density of the converter stations and DC transmission lines(DL/T 1089—2008).The results were evaluated according to occupational exposure limits recommended by The limits of electromagnetic environment at±800 kV UHV DC converter station(DL/T 275—2012),the American Conference of Governmental Industrial Hygienists(ACGIH),and the International Commission on Non-Ionizing Radiation Protection(ICNIRP).[Results]A total of 615 check points were planned,the total electric field strength was 0.05-37.05 kV·m^(−1),and the median was 10.45 kV·m^(−1).The total electric field strength of 39 check points(6.3%)exceeded 25 kV·m^(−1)(the limits of ACGIH and ICNIRP),and the total electric field strength of 12 check points(2.0%)exceeded 30 kV·m^(−1)(the limit of DL/T 275—2012).There were statistically significant differences in the total electric field strength values and the proportions of exceeding 25 kV·m^(−1)between the neutral regions and the positive regions and between the neutral regions and the negative regions(P<0.01).The proportion of total electric field strength exceeding 30 kV·m^(−1)in the negative regions was higher than that in the positive regions(P<0.01).There were no significant differences in the total electric field strength of converter stations at different voltage levels and different altitudes(P>0.05).There were no significant differences in the proportions of total electric field exceeding 25 kV·m^(−1)and exceeding 30 kV·m^(−1)in converter stations at different voltage levels and different altitudes(P>0.05).[Conclusion]The total electric field in some workplace of converter stations exceeds selected limits.Converter station operators may be exposed to high-strength total electric field for a short time.