【摘要】 变压器在因电力故障继电保护动作或因运行方式改变等原因而退出运行后再次投运时铁心剩磁并不是随机的。在分析磁性材料的时效特性的基础上,结合Preisach模型及其特性,推导出了分段计算铁心剩磁的方法。在此基础上,对单相变压器抑制励磁涌流的控制合闸角策略进行分析,推导出合闸角控制律,EMTP实验验证了该策略的正确性。同时,仿真实验揭示了在给定电流超调裕度下不同剩磁环境所对应的合闸角波动范围的变化规律;最后,遵循该规律,提供了设计单相变压器抑制励磁涌流装置的分段合闸角策略。更多还原

【Abstract】 When a transformer is switched back into power system operation again without load from last switching off, due to either the action of protective device aiming at the system fault or the changes of system framework structure, the residual flux of ferromagnetic-core is non-random. Based on the time-characteristic of ferromagnetic material analysis, combined with Preisach model, a way to calculate residual flux is proposed. An expression between the residual flux and the entering-phase is derived to eliminate inrush current in single-phase transformer and its correctness is shown by an EMTP test. Meanwhile, some rules between the residual flux and the range of entering-phase at a given overshoot limit of inrush current are demonstrated in the simulations. Finally, these rules have been used to propose a control strategy about entering-phase in sections to design a device to eliminate the inrush current.更多还原