直流偏磁對(duì)測量用CT影響及補(bǔ)償方法的研究
申路，裴東鋒，未超，姜艷豐
（國網(wǎng)邯鄲供電公司，河北 邯鄲 056000）
摘 要：直流偏磁會(huì)改變測量用電流互感器(CT) 的傳變特性，直接影響電能計(jì)量與測量的準(zhǔn)確性。分析了直流偏磁的產(chǎn)生機(jī)理，根據(jù)測量用CT 的等效電路建立起仿真電路，研究了直流偏磁對(duì)測量用CT比差、角差及勵(lì)磁電流的影響。結(jié)果表明直流偏磁的存在會(huì)使比差、角差向著不同方向增大，并會(huì)引起勵(lì)磁電流增大、波形正負(fù)半周不對(duì)稱、偶次諧波增加，嚴(yán)重影響CT 的傳變精度。提出了一種減少測量用CT 計(jì)量與測量誤差的補(bǔ)償方法，仿真驗(yàn)證了該方法的有效性。
關(guān)鍵詞：測量用電流互感器；直流偏磁；勵(lì)磁電流；比差；角差；補(bǔ)償
中圖分類號(hào)：TM452 文獻(xiàn)標(biāo)識(shí)碼：A 文章編號(hào)：1007-3175(2017)03-0023-05
Research on Influence of Direct Current Magnetic Bias on Measuring Current Transformer and
Its Compensation Measures
SHEN Lu, PEI Dong-feng, WEI Chao, JIANG Yan-feng
（State Grid Handan Electric Power Supply Company, Handan 056000, China）
Abstract: Direct current (DC) bias will change the current transformer (CT) transfer characteristics and has a direct impact on the accuracy of electric energy metering and measurement. Analysis was made to the formation mechanisms of direct current magnetic bias. This paper established the simulation circuit according to the equivalent circuit of measuring CT and researched the influence of DC magnetic bias on ratio error, phase displacement and exciting current of measuring CT. The results show that DC magnetic bias will increase the ratio error and phase displacement in opposite directions, making the exciting current increase, the waveforms plus or minus semi-cycle asymmetry, a lot of evenorder harmonics generate, which seriously affects the transmission transformer accuracy of CT. A kind of compensation method was proposed to reduce measuring CT computation and measuring errors. The simulation verifies the validity of this method.
Key words: measuring current transformer; direct current bias; exciting current; ratio error; phase displacement; compensation
參考文獻(xiàn)
[1] 陳黎來. 電流互感器對(duì)電能計(jì)量的影響[J]. 電力自動(dòng)化設(shè)備，2011，31(1)：138-141.
[2] 趙畹君. 高壓直流輸電工程技術(shù)[M]. 北京：中國電力出版社，2005．
[3] 鄭崗， 熊列彬， 邢桂鳳， 等. 電流互感器飽和及其影響因素的仿真研究[J]. 電氣開關(guān)，2010，48(6)：41-43.
[4] 肖偉平，黃紹平. 基于MATLAB的電流互感器飽和特性仿真分析[J]. 變壓器，2005，42(5)：27-30.
[5] 崔迎賓，譚震宇，李慶民，等. 電流互感器剩磁影響因素和發(fā)生規(guī)律的仿真分析[J]. 電力系統(tǒng)自動(dòng)化，2010，34(23)：87-91.
[6] 張燕秉，劉連光，姚謙，等. 基于PSCAD/EMTDC的電網(wǎng)GIC影響仿真分析[J]. 華北電力技術(shù)，2004(6)：10-13.
[7] 李長云，李慶民，李貞，等. 直流偏磁條件下電流互感器的傳變特性[J]. 中國電機(jī)工程學(xué)報(bào)，2010，30(19)：127-132.
[8] IEEE 1057: 2007 IEEE standard for digitizing waveform recorders[S].
[9] YAO Yingying，KOH C S, NI Guangzheng，et al. 3-D nonlinear transient eddy current calculation of online power transformer under DC bias[J].IEEE Transactions on Magnetics，2005，41(5)：1840-1843．
[10] GB 50150—2006 電氣裝置安裝工程電氣設(shè)備交接試驗(yàn)標(biāo)準(zhǔn)[S].
