Electric Circuit and Magnetic Circuit Combined Model of Three-Phase Three-Legged Transformer under DC Bias
An electric circuit and magnetic circuit coupled model of the DC biased three-phase three-legged transformer was built. In the model, the magnetic circuit was set up by a practical PSPICE model with accurate performance for the three-phase three-legged saturated transformer. Meanwhile, the electric circuit equation under DC bias was built. Then, two matrix equations were formed. The matrix equations are dispersed and solved by iterative method. The waveform of the flux and exciting current for the three-phase three-legged transformer were gained in MATLAB. The simulation results show that DC current will lead to the flux and exciting current bias, but could not make the flux and exciting current distort. And the exciting current of the three-phase three-legged transformer is smaller than that of the single-phase transformer with the same rated power because of the magnetic coupling among three legs.
Keywordsthree-phase three-legged transformer DC bias exciting current magnetic circuit
Unable to display preview. Download preview PDF.
- 1.A report prepared by the IEEE transmission and distribution committee working group on geomagnetic disturbance and power system effects: Geomagnetic disturbance effects on power systems. IEEE Trans. on Power Delivery 8(3), 1206 (1993)Google Scholar
- 3.Li, X.P., Wen, X.S., Lan, L., et al.: Test and simulation for single-phase transformer under DC bias. Proceedings of the CSEE 27(9), 33–40 (2007)Google Scholar
- 7.Li, X.Y., Chen, L.Y., Yan, Q., et al.: Design of nonlinear complementary controllers for multi-infeed HVDC transmission systems. Proceedings of the CSEE 25(15), 16–19 (2005)Google Scholar
- 8.Zhu, Y.Y., Jiang, W.P., Zeng, Z.H., et al.: Studying on measures of restraining DC current through transformer neutrals. Proceeding of the CSEE 25(13), 1–7 (2005)Google Scholar
- 9.Ma, Y.L., Xiao, X.N., Jiang, X., et al.: Optimized grounding resistance configuration against DC magnetic bias of large capacity power transformer. Power System Technology 30(3), 62–65 (2006)Google Scholar