电流互感器初始剩磁系数与稳态剩磁系数的研究

剩磁是影响电流互感器传变特性的关键因素,剩磁问题的研究对于保证电流互感器正常传变以满足控制、保护及计量要求有重要意义。针对铁心剩磁存在状态的问题,提出初始剩磁与稳态剩磁的概念,从磁畴运动角度分析剩磁的不同物理状态,并定义了初始剩磁系数与稳态剩磁系数。通过动模试验,测得不同电压等级下电流互感器饱和磁通、剩磁、剩磁系数的变化趋势。试验表明,初始剩磁系数与稳态剩磁系数相差较大,间接证明了电流互感器剩磁存在不同状态,对于厘清电流互感器暂态传变特性及其变化规律、研究剩磁作用对计量与保护控制系统的影响意义重大。

Research on Initial Remanence Coefficient and Stable Remanence Coefficient of Current Transformer

Remanence of current transformer is a key factor of inflencing its transfer characteristic. Study on remanence to meet the requirements of control, protection, metering has important significance. Aiming at the status of remanence existing in core, the concept of initial remanence and steady-state remanence were proposed in this paper. According to the magnetic domain movement, different physical states of remanence were analyzed. And then the definition of initial and steady-state remanence coefficient were given. On the basis of physical experiment in the lab, the trend of saturation magnetic flux, remanence and remanence coefficient were measured under different voltage levels. Based on experiment data, the initial remanence coefficient and steady-state remanence coefficient are vary considerably, which proves indirectly that the remanence of current transformer exists different states. It is of great significance to clarify the transient transfer characteristics and change rule of current transformer and to study the impacts of remanence on the measurement and protection control system.