Study on winding vibration suppression of new HVDC converter transformer

Nonlinear loads in valve side of high-voltage direct current(HVDC) converter transformer produces a mass of harmonic currents, and DC magnetic bias phenomena also affects the converter transformer. As a result, harmonic currents in the windings and harmonic flux in the core of converter transformer increases, which leads to more serious vibration of windings and core. It has become a new problem in HVDC project. Winding electromagnetic vibration of a new converter transformer considering harmonic currents was studied. Transformation matrices from load currents to windings' currents were proposed and the electromagnetic forces of windings were calculated by Lagrange's theorem. The 3-D finite element method(FEM) model of windings and core was established. Finally, the windings' vibration characteristics were determined by computing the FEM model with transient dynamic analysis method. Finally, the windings' vibration was tested, and the experimental data verified the correctness of the FEM simulation. The result reveals that the new HVDC converter transformer can suppress the windings' vibration. © 2019, Harbin University of Science and Technology Publication. All right reserved.