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％.
关键词
载波移相正弦脉宽调制/级联H桥/变压器/硅钢片/铁耗
Key words
CPS-SPWM/cascaded H-bridge/power transformers/silicon steel sheet/iron loss
维普
万方数据