Abstract：DC bias of transformer will lead to the increase of noise, vibration and heat , injected a large number of harmonics into the grid , affect the correct operation of protection devices and reduce the system voltage etc. Therefore, the study of DC bias and its suppression measures have a great practical significance and long-term strategic significance. The model of transient electromagnetic field of single-phase transformer had been established to analyze the internal magnetic field changes in core and yoke under different DC currents by using finite element analysis software -Maxwell 2D. Based on the Unified Magnetic Equivalent Circuit (UMEC) model of transformer, the excitation current and its harmonic when DC bias occurs had been analyzed by using PSCAD. The effects to inhibit DC bias of self-excited compensation method and applied DC compensating power supply method had been compared. The simulation results shows when the transformer under DC bias, the leakage flux increases, which leads to the core heated, the highest temperature appears in the junction of yoke and core. The self-excited compensation method and applied DC compensating power supply method have significant effect to suppress DC bias of transformer.
张师赫, 苏帅, 刘青. 单相变压器直流偏磁及抑制措施分析[J]. 电气技术, 2016, 17(4): 25-28.
Zhang Shihe, Su Shuai, Liu Qing. Analysis of DC Bias and Suppressing Measure of Single-phase Transformer. Electrical Engineering, 2016, 17(4): 25-28.
2016, Vol. 17 
