一種帶開關量的開口式電流互感器的應用

syt

蘇月婷

江蘇安科瑞電器制造有限公司

       摘 要：介紹了開口式電流互感器在改造項目中的應用，以及帶開關量的開口式電流互感器的作用，和常規開口互感器對比的優勢，并結合工程實例分析。

  Abstract：Introduces the application of open type current transformer in the renovation project, as well as the role of open type current transformer with switching quantity, and the advantages of comparison with conventional open type current transformer, and analyzes with engineering examples.

  關鍵詞 ：低壓配電系統 開關量 開口式 電流互感器 防竊電 工作原理

  Keywords low voltage distribution system, switching, open type current transformer, anti-theft, working principle

  1.引言 Introduction

  隨著我國電力工業中城網及農網的改造，以及低壓配電系統的自動化程度不斷提高，開口式電流互感器作為低壓配電系統中的一種重要電氣元件，在電網改造中的作用越來越明顯，已被廣泛地應用于測量、計量、繼電保護、系統監測、接地保護和各種電力系統分析之中。

  With the transformation of urban and agricultural networks in China's power industry and the increasing automation of low-voltage distribution systems, open type current transformers, as an important electrical component in low-voltage distribution systems, have become more and more obvious in the transformation of power grids and have been widely used in measurement, metering, relay protection, system monitoring, grounding protection and various power system analysis.

  但是，目前市場上的開口式低壓互感器在安裝的時候可能會出現卡扣沒卡緊導致鐵芯沒有完全閉合；或者在運行過程中，互感器外殼受到很大應力作用，外殼鉸鏈斷裂，導致上下鐵芯不閉合，影響互感器精度或者沒有電流輸出。帶開關量的開口式電流互感器能夠有助于向儀表或者后臺反饋上述情況，在電力監控項目上有廣闊的運用前景。

  However, the open type low-voltage transformers on the market at present may be installed with snaps that are not tightened to cause the core to be not completely closed; or during operation, the transformer shell is subjected to great stress and the shell hinge breaks, resulting in the upper and lower cores not being closed, affecting the accuracy of the transformer or no current output. The open type current transformer with switch can effectively feedback the above situation to the instrument or the background, and has a broad application prospect in power monitoring projects.

  2.電流互感器工作原理 Working principle of current transformer

  開口低壓電流互感器的工作原理如圖1所示，開口電流互感器的一次繞組串聯在被測線路中，I1為線路電流即電流互感器的一次電流，N1為電流互感器的一次匝數，I2電流互感器二次電流，N2為電流互感器的二次匝數，Z2e為二次回路設備及連接導線阻抗。當一次電流從電流互感器P1端流進，P2端出，在二次Z2e接通的情況下，由電磁感應原理，電流互感器二次繞組有電流I2從S1流過，經Z2e至S2，形成閉合回路。由此可得電流在理想狀態下I1×N1=I2×N2，

  所以有I1/I2=N1/N2=K，K為電流互感器的變比。但是由于開

  口式電流互感器的鐵芯切開后，使鐵芯的性能下將的比較厲害，所以要將互感器的鐵芯截面積加大，而且提高安匝數，將I1×N1=I2×N2≥100AN。

  The working principle of the open-ended low-voltage current transformer is shown in Figure 1. The primary winding of the open-ended current transformer is connected in series with the line under test, I1 is the line current, that is, the primary current of the current transformer, and N1 is the primary turns of the current transformer. I2 is the secondary current of the current transformer, N2 is the secondary turns of the current transformer, and Z2e is the impedance of the secondary circuit equipment and connecting wires. When the primary current flows in from the P1 end of the current transformer, and the P2 end goes out, in the case that the secondary Z2e is turned on, according to the principle of electromagnetic induction, the secondary winding of the current transformer has a current I2 flowing from S1, through Z2e to S2, form a closed loop. It can be obtained that the current is I1×N1=I2×N2 in the ideal state, so there is I1/I2=N1/N2=K, and K is the transformation ratio of the current transformer. However, after the iron core of the open current transformer is cut, the performance of the iron core will be worse, so the cross-sectional area of the iron core of the transformer must be increased, and the number of ampere turns must be increased, and I1×N1=I2 ×N2≥100AN.

     

  另外，該互感器上的開關量開關，當互感器卡扣沒卡好或是互感器老化導致殼體破裂，開關按鈕彈起，常閉變常開，信號終止傳輸，互感器無信號輸出；當互感器卡扣正常是，開關狀態為常閉，互感器正常工作。

  In addition, the transformer on the switch, when the transformer snap did not card or the transformer aging caused by the rupture of the shell, the switch button pops up, normally closed to normally open, the signal termination transmission, the transformer no signal output; when the transformer snap is normal, the switch state is normally closed, the transformer works normally.

  3.開口式電流互感器Open type current transformer

  開口式電流互感器主要應用于工業中城網、農網改造項目。特點是安裝方便，無需拆除一次母線，亦可帶電操作。但是，目前市場上的低壓開口式互感器存在以下缺點：

  Open type current transformers are mainly used in industrial city network and agricultural network renovation projects. Features are easy to install, no need to remove the primary busbar, and can also be operated with electricity. However, the current low-voltage open type transformers on the market have the following drawbacks.

               

  （1）市場上的開口式電流互感器在安裝的時候可能會出現卡扣沒卡緊或是鐵芯沒有閉合，在運行過程中會出現互感器脫落或者斷開的風險；

  (1) Open type current transformer on the market may not be installed when the clasp is not tight or the core is not closed, the risk of the transformer falling off or disconnected during operation.

  （2）開口式電流互感器在安裝后如果被人為二次打開后，會出現無信號等問題。

  針對上述不足，AKH-0.66/K-SW系列電流互感器，可以解決上述問題。此互感器外形美觀，安裝維護方便簡潔。如圖2所示，該互感器具備以下幾個優點：

  Open type current transformer will have no signal and other problems if it is artificially opened twice after installation.

  AKH-0.66/K-SW series current transformer can solve the above problems. This transformer has a beautiful appearance and is easy and simple to install and maintain. As shown in Figure 2, the transformer has the following advantages.

  （1）AKH-0.66/K-SW系列電流互感器，安裝時無需將電斷開，可以帶電操作，閉合直接使用即可現場安裝簡便，減少人力成本；

  AKH-0.66/K-SW series current transformer, installation without disconnecting the electricity, you can operate with electricity, close the direct use of the site installation is simple, reducing labor costs.

  （2）AKH-0.66/K-SW系列電流互感器，在該模塊有4根引線，兩根傳輸電流信號，兩根傳輸開關量信號；

  AKH-0.66/K-SW series current transformer, there are four leads in the module, two to transmit the current signal, two to transmit the switching signal.

  （3）AKH-0.66/K-SW系列電流互感器，當卡扣沒卡好或是互感器老化導致殼體破裂，上下殼體彈開，鐵芯接觸不良，卡在互感器下殼體的開關凸起按鈕就會向上彈出，開關斷開，開關量信號終止傳輸，起到提示開口式低壓互感器停止工作的作用。

  AKH-0.66/K-SW series current transformers, when the buckle is not locked or the transformer is aging, the casing is broken, the upper and lower casings pop open, the iron core is in poor contact, and the switch stuck on the lower casing of the transformer protrudes The button will pop up, the switch will be disconnected, and the switching signal will terminate the transmission, which will prompt the open-type low-voltage transformer to stop working.

  （4）AKH-0.66/K-SW系列電流互感器，上下殼體帶有鉛封孔，一旦安裝完畢立即進行鉛封。

  AKH-0.66/K-SW series current transformer, the upper and lower shells with lead seal holes, once the installation is completed immediately lead seal.

  4.參數對照表Parameter comparison table

  4.結束語Conclusion

  AKH-0.66/K-SW系列電流互感器的出現，具備異常打開報警、停上電事件上報等功能，同時也為企業降低了人力物力成本，由于市場巨大，一旦形成生產能力，也可帶動其他行業的飛速發展。

  The emergence of AKH-0.66/K-SW series current transformer, with abnormal open alarm, stop on the power event reporting and other functions, but also for the enterprise to reduce the cost of human and material resources, due to the huge market, once the formation of production capacity, but also can drive the rapid development of other industries.