Total electric field intensity in workplace of high-voltage direct current converter stations
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。
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
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.
To understand the current situation of total electric field strength in the workplace of converter stations.
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.