New High-Accuracy Low-Cost Approach for tan6 On-line Monitoring Based on MCU

Through analyzing the principle of micro-current sensor and the shortage of "zero-flux" micro-current sensor, a new on-line monitoring method of dielectric tangent of loss angle (tandelta) based on passive micro-current sensor technology is presented. This method can not only overcome difficulties existing in the manufacturing sensors of the high precision relative scale difference and the high precision angular difference which is often necessary in on-line monitoring of insulation dielectric tandelta, but also can achieve high precision at low cost. This method combines the balance measurement principle and potential computer difference measuring technology, and it can be easily realized by using micro-controller unit (MCU). It also adopts anti-circumstance electromagnetic interference and intelligent diagnostic techniques in the course of measurement, so it possesses great anti-interference ability under strong electromagnetic interference environment. Both the principle analysis and the on-site test have proved that this measure method can reach good tandelta monitoring precision