Differential protection device and method of traction transformer and train

The invention provides a differential protection device and method of a traction transformer and a train, and can be applied to the technical field of rail transit traction power supply systems. The differential protection device of the traction transformer comprises a current transformer which is used for simultaneously inducing current in a power supply end cable of the traction transformer and current in a grounding end cable of the traction transformer to obtain induced current; the acquisition unit is used for acquiring induction current in the current transformer; and the processing unit is used for triggering the traction transformer to carry out differential protection under the condition that the induction current is greater than a preset threshold value. 本公开提供了一种牵引变压器的差动保护装置、方法及列车，可以应用于轨道交通牵引供电系统技术领域。该牵引变压器的差动保护装置包括：电流互感器，用于同时对牵引变压器的供电端线缆中的电流以及牵引变压器的接地端线缆中的电流进行感应，得到感应电流；采集单元，用于采集电流互感器中的感应电流；处理单元，用于在感应电流大于预设阈值的情况下，触发牵引变压器进行差动保护。