目前牵引变压器差动保护原理在某些因素的影响下并不能准确地区分变压器内部故障和外部故障，可能造成保护误动或拒动，危及电气化铁道系统的安全运行。针对这一现状，建立了计及铁芯非线性特性和磁滞效应而又无需铁芯的B－H曲线数据的牵引变压器模型，提出了一种通过参数辩识理论来辩识牵引变压器绕组参数实现牵引变压器微型机保护的方法。该方法能有效地区分内部故障、外部故障和励磁涌流。仿真计算表明了该方法的正确性和可行性。-Traction transformer differential protection principle in the safe operation and can not accurately distinguish between the transformer internal faults and external faults, may be to cause protection mistaken or refuse to move, endangering the electrified railway system under the influence of certain factors. In response to this situation, taking into account the core nonlinear characteristics and hysteresis and without traction transformer core of the B-H curve data model, a the traction transformer winding identification through parameter identification theory parameters to achieve traction transformer microcomputer protection. This method can effectively distinguish internal faults, external faults and magnetizing inrush current. The simulation results show that the correctness and feasibility of the method.