Fast Calculation Method for Iron Loss of Transformer Fed by Cascaded H-Bridges with CPS-SPWM
Aiming at the transformer fed by cascaded H-bridges with carrier phase-shifted(CPS)sinusoidal pulse-width modulation(SPWM),a fast method is proposed to calculate the iron loss on the basis of the classical loss separation model.Firstly,the lumped duty cycle of the SPWM voltage waveform is defined,and the analytical model for modulation ratio is derived.Secondly,based on the classical loss separation model and the lumped duty cycle,the iron loss calculation model is built for CPS-SPWM cascaded H-bridge.The method can directly use the modulation ratio,DC bus voltage,and other parameters to calculate the iron loss,thus avoiding the harmonic analysis or numerical integration process in conventional methods.Then,based on the proposed iron loss model,an equivalent simulation method is proposed for the iron loss under the SPWM voltage excitation.With this method,the relative error of iron loss is less than 3.6％and the used time is reduced by 74.5％.Finally,the proposed method is verified by experiments and the maximum calculation error of iron loss is less than 7.6％.
CPS-SPWMcascaded H-bridgepower transformerssilicon steel sheetiron loss
万方数据
维普
