变压器一次侧匝间短路参数与特征分析

Analysis of Parameters and Characteristics of Inter-turn Short-circuit Fault on Primary Side of Transformer

变压器作为电力系统中传送电能的关键设备,其一次侧发生匝间短路产生的故障电流将对变压器本身、发电机和电网产生较大冲击,影响电力系统的电能质量和稳定性。针对变压器匝间短路电流计算问题,通过试验变压器的稳态和暂态实测数据在三维有限元软件FLUX中建立仿真模型,基于此模型,进行不同匝数和位置的匝间故障仿真。同时考虑绕组自感、互感与短路匝数及位置的关系,提出了一种根据回路电压方程组计算故障电流的方法。与FLUX得到的仿真结果对比,验证了计算方法的正确性。最后通过FLUX软件的后处理功能对比研究了变压器发生不同类型匝间短路后的内部电磁场变化规律。

Transformer is the key equipment to transmit electric energy in the power system. A fault current generated by inter-turn short-circuit fault on the primary side of transformer will have a great impact on the transformer itself, the electric generator and the power grid. Besides, it makes an influence on the quality and stability of the electric energy of the power system. Aiming at the problem of calculating the inter-turn short-circuit current of transformer, by testing the measured data of steady and transient state of transformer, a simulation model in the 3D finite element software-FLUX is established. On the basis of this model, the inter-turn fault simulation is conducted with different turns and at different positions. Meanwhile, considering the relationship between the self and mutual inductance of windings and the number of turns and positions of short-circuit fault, a method for calculating fault current is put forward according to the circuit voltage equation. Compared with the simulation results obtained by FLUX, the validity of the calculation method is verified. By means of the post-processing function of the FLUX software, the change rules of the internal electromagnetic field after different types of transformer inter-turn short-circuit faults are finally studied by comparison.