Research on Recognition Method for Excitation Surge Current Protection of Transformer
Yangchun Cheng · Guangdong Electric Power · 2012
On the basis of introducing and analyzing cause,mechanism of surge current and several braking principles of current protective devices,the paper mainly introduces existing problems in secondary harmonic brake and proposes new measures for enhancing recognition capability of excitation surge current protection of transformer:improve phasic braking by adjusting differential current;add value fixing function of floating threshold of surge current;capture the trend criterion of secondary harmonic data by means of algorithm;equip the differential protection device with self-adaptive cycling locking. These measures can handle disadvantages of secondary harmonic braking and greatly improve safety and flexibility of transformer protection.