一种消除单相变压器励磁涌流的预充磁策略

摘要

Energization of transformer both unload and removal of fault is accompanied with an inrush current, the value of which depends on the angle of the applied voltage, residual flux of the core, the impedance of system and so on. A strategy of eliminating the single-phase transformer inrush current is proposed, which refers to set the transformer residual flux to a known value which is equal to the flux when energization by a pre-magnetizing device, while decreases the inrush current. By theoretical analysis, the relationship between size of capacitor and the voltage, the degree of magnetization of the core and the corresponding phase are determined. Finally, in case of a single-phase transformer, the proposed strategy is verified by Simulink simulation.%变压器空载合闸或切除故障合闸都伴随着励磁涌流的出现，励磁涌流的大小受合闸角、剩磁、系统阻抗参数等因素的影响。提出了一种消除单相变压器励磁涌流的策略，利用预充磁装置改变变压器铁心中的磁通，当接近极限磁滞回线的剩磁时，控制断路器的合闸，从而消除励磁涌流。通过理论推导，确定了预充磁装置电容大小与电容电压之间的关系、铁心的充磁程度以及对应的相位。最后，以某单相变压器为例，利用Simulink仿真，验证了该策略。