【摘要】：對保護(hù)用電流互感器在大電流時的性能進(jìn)行校驗時一般采用含鐵芯的電磁式互感器作為標(biāo)準(zhǔn)。但電流較大時,電磁式互感器鐵芯體積大、制造困難,且剩磁現(xiàn)象嚴(yán)重,導(dǎo)致其誤差變大。為此,提出了一種基于空心線圈互感系數(shù)自校驗原理的交流大電流校驗系統(tǒng)。在小電流時,該系統(tǒng)利用鐵芯線圈的輸出來校正空心線圈的安裝等外界因素可能造成的誤差。由于空心線圈的線性度好,校準(zhǔn)后的空心線圈可作為大電流校驗時的電流標(biāo)準(zhǔn)。空心線圈的輸出需要積分還原,采用基于直流負(fù)反饋原理的數(shù)字積分算法,有效克服了傳統(tǒng)模擬積分電路和數(shù)字積分的零漂、時漂和直流偏移問題。測試結(jié)果表明,該系統(tǒng)在電流500 A~50 kA范圍內(nèi)可達(dá)到0.1級的準(zhǔn)確度。
[Abstract]:The electromagnetic transformer with iron core is generally used as the standard to verify the performance of the current transformer for protection at high current. However, when the current is large, the core of the electromagnetic transformer is large, the manufacture is difficult, and the remanence phenomenon is serious, which leads to the bigger error. In this paper, an AC high current calibration system based on the principle of mutual inductance self-calibration of hollow coil is proposed. At low current, the system uses the output of iron core coil to correct the error caused by external factors such as the installation of hollow coil. Because of the good linearity of the hollow coil, the calibrated hollow coil can be used as the current standard for high current calibration. The output of hollow coil needs integral reduction. The digital integral algorithm based on DC negative feedback principle is used to overcome the problems of zero drift, time drift and DC offset of traditional analog integral circuit and digital integral. The test results show that the accuracy of the system can reach 0.1 level in the current range of 500A 鈮，

本文編號：2521080