Design of a High-Precision AC/DC Clamp Ammeter Based on a Self-Calibration Technique
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摘要: 为解决新能源发电换电并网以及非线性负载给交流供电系统带来直流分量,致使工作中钳形电流表失准、失效甚至损毁的问题,分析了传统交流钳形表适用性的劣势,设计了一款基于霍尔元件直流补偿和自校准技术的现场校验用交直流钳形电流表。进行了测量不确定度评定,量程内选择的所有交直流校准点相对测量不确定度优于0.2%,样机准确度等级优于0.5级。与传统交流钳形表进行了交直流测量比较的观察测试试验,表明设计的钳形表可实现交直流测量,符合设计预期,其代表技术具有广泛推广价值。Abstract: In order to solve the problems of misalignment, failure and even damage of clamp ammeters in operation due to that the new energy power generation, grid connection and nonlinear load bring DC components to the AC power supply system, the disadvantages and applicability of traditional AC clamp ammeters were analyzed, and an AC/DC clamp ammeter for field calibration based on the Hall component DC compensation and a self-calibration technique was designed. The extended measurement uncertainty was evaluated. The relative uncertainty at all the selected AC/DC calibration points was within the range of 0.2% and the accuracy grade of the prototype was equal to and even better than 0.5 grades. The prototype was compared with traditional AC clamp ammeters through a test experiment. The results of the experiment indicated the capability of the designed clamp ammeter to make AC/DC measurement, which met the design requirements and showed its potential for application.
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Key words:
- new energy /
- grid connection /
- AC/DC clamp ammeter /
- hall component /
- DC compensation /
- self-calibration
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表 1 交流电流校准点测量不确定度一览表
Table 1. Measurement uncertainty at selected AC current calibration points
校准点(A) 不确定度分量(A) ${u_{\rm{c}}}\;({\rm{A} })$ $U\;({\rm{A}})\;\;(k = 2)$ ${U_{\rm rel} }$ $u({I_{x_1} })$ $u({I_{x_2} })$ $ u({I_0}) $ 8 0.007 0.003 0.001 0.008 0.016 0.20% 16 0.013 0.003 0.002 0.013 0.027 0.17% 24 0.024 0.003 0.003 0.024 0.049 0.20% 32 0.025 0.003 0.004 0.025 0.051 0.16% 40 0.038 0.003 0.005 0.038 0.077 0.19% 380 0.324 0.029 0.044 0.328 0.656 0.17% 表 2 直流电流校准点测量不确定度一览表
Table 2. Measurement uncertainty at selected DC current calibration points
校准点(A) 不确定度分量(A) ${u_{\rm{c}}}\;({\rm{A} })$ $U\;({\rm{A}})\;\;(k = 2)$ ${U_{\rm rel} }$ $u({I_{x_1} })$ $u({I_{x_2} })$ $ u({I_0}) $ 8 0.006 0.003 0.001 0.007 0.014 0.18% 16 0.011 0.003 0.002 0.012 0.023 0.14% 24 0.022 0.003 0.003 0.022 0.045 0.19% 32 0.024 0.003 0.004 0.025 0.049 0.15% 40 0.037 0.003 0.005 0.035 0.071 0.18% 380 0.324 0.029 0.044 0.328 0.656 0.17% -
[1] 许原, 黄艳. 新能源与智能电网产业计量测试服务平台的建立及服务模式研究[J]. 计量技术, 2019(1): 59-61. [2] 吕志盛, 闫立伟, 罗艾青, 等. 新能源发电并网对电网电能质量的影响研究[J]. 华东电力, 2012, 40(2): 251-256. [3] 盛万兴, 吴鸣, 季宇, 等. 分布式可再生能源发电集群并网消纳关键技术及工程实践[J]. 中国电机工程学报, 2019, 39(8): 2175-2186+1. [4] 吉孝明. 风电新能源并网技术研究[J]. 电子世界, 2021(2): 27-28. [5] 宋晓林, 马烨, 孙刚, 等. 复杂工况下直流电能计量的算法影响及误差分析[J/OL]. 电测与仪表: 1-8[2021-02-08]. http://kns.cnki.net/kcms/detail/23.1202.th.20201221.1726.002.html. [6] 王晨迪. 直流配电网电能质量问题的检测与治理研究[D]. 西安: 西安理工大学, 2020. [7] 张瑞, 刘相增, 周鑫. 一种基于六谱线插值FFT的并网风电场谐波分析系统[J]. 计量技术, 2020(2): 22-26. [8] 刘润民. 电能表现场校验仪常见问题解析[J]. 计量技术, 2008(7): 70-71. [9] 应慧娟, 赵德, 施笑琴, 等. 一种电光混合式保护用电流互感器的设计新方法[J]. 计量技术, 2016(5): 22-26. [10] 沈明炎. 隔离型电能表检验装置小电流溯源失准的研究[J]. 计量技术, 2016(1): 43-46. [11] 袁佳歆, 张朝阳, 周航, 等. 交流饱和铁芯型故障限流器的现状与发展[J]. 电力自动化设备, 2020, 40(5): 209-221. [12] 才滢, 黄全胜, 李莉. DC100A直流电流标准的研制[J]. 计量技术, 2006(2): 12-14. [13] 苏野. 干式电流、电压互感器烧毁原因及预防措施[J]. 中国新技术新产品, 2020(5): 147-148. doi: 10.3969/j.issn.1673-9957.2020.05.068 [14] 国家质量监督检验检疫总局. 钳形电流表校准规范: JJF 1075-2015 [S]. 北京, 2015. [15] 邵万里. 防止变压器铁芯饱和的方法[J]. 电工技术, 2020(7): 90-91,94.