摘要
电炉变压器低压侧的大电流造成常规CT体积过大无法安装,无法采用差动保护作为变压器内部故障的主保护,而传统的高压侧过流保护在变压器内部故障时灵敏度又不满足要求。在分析了电炉变压器内部构造的基础上,基于成熟的光纤通信技术、电子式电流互感器技术及高性能微机保护技术,通过在低压侧装设电子式电流互感器并根据调压分接开关的位置自动调整差动保护平衡系数,实现了基于三侧电流的差动保护方案,解决了电炉变压器由于过载倍数高、调压范围宽造成差动保护原理实施困难的问题。试验结果表明,电炉变压器差动保护能明显提高变压器内部故障时保护装置的灵敏性和可靠性。
Furnace transformer’s low voltage side current is too large to measure with conventional current transformer,so it can’t use differential protection as the main protection for internal faults.But traditional over-current protection at high voltage side can not meet the requirements of the protection sensitivity when internal fault occurs.Based on analyzing furnace transformer’s internal structure,mature fiber communication technology,electronic current transformer technology and high-performance computer protection technology,with installing electronic current transformer for the low voltage side wire leads and automatically adjusting the balance coefficient according to the position of the voltage regulating tap in the differential protection module,this paper proposes a current differential protection scheme for three sides transformers,which can solve the problem that it is difficult to implement the differential protection due to the high overload factor and wide voltage regulation range of the transformers.Simulation results show that,with this current differential protection,it can significantly improve the protection’s sensitivity and reliability when internal transformer fault occurs.
出处
《电力系统保护与控制》
EI
CSCD
北大核心
2011年第9期114-118,124,共6页
Power System Protection and Control
关键词
电炉变压器
差动保护
灵敏度
电子式电流互感器
furnance transformer
differential protection
sensitivity
electronic current transformer
