Analysis Of The No-Loading EMF Waveform Of Powerformer

In the paper, the design characteristic and development situation of powerformer are introduced; the structure of prototype is studied; the no-loading magnetic field is analyzed using the finite element method; the suitable harmonic analysis algorithm is sought. On the basis of these theories, the no-loading EMF of powerformer is analyzed and the no-loading waveform deviation factor is taken out, in the conditions of considering the influence of damping winding and not considering it. While analyzing every condition, whether the core is saturated or not is considered. In these conditions, the no-loading electric motive forces are contrasted and analyzed.Considering the influence of damping winding and if core is saturated or not, the no-loading EMF waveform of a conventional generator having the same size with the prototype (except the stator slot) is analyzed, and the waveform deviation factor is taken out. The no-loading EMF of prototype and the no-loading EMF of conventional generator are contrasted and analyzed, in the condition of considering the influence of damping winding and core saturation.According to the no-loading waveform deviation factor, the prototype conforms to the national design standard and practical needs in the engineering. More important, the high voltage is achieved. In the condition of considering core saturation and damping winding influence, the influence to powerformer of the no-loading tooth harmonic EMF is smaller than conventional generator, and the waveform deviation factor of the former is smaller, too. The program and the work in the paper have some practical value, and can be used in the engineering.