考虑共模电压和中点电压的T型三电平逆变器调制方法

Modulation Methods of T-type Three-level Inverter Considering Common-mode Voltage and Neutral-point Voltage

与两电平逆变器相比,T型三电平逆变器具有输出电压波形正弦度更高、谐波特性更好等优点,因此得到了广泛的研究和应用。在60。坐标系下以小矢量为中心给出了基于两电平的T型三电平逆变器的空间矢量脉宽调制(SVPWM)方法。为了抑制共模电压,提出了采用共模电压幅值较小的矢量合成共模电压幅值较大的中心小矢量,将共模电压大小限制到直流母线电压的六分之一。在抑制共模电压的基础上研究了不同方案的中点电压调节能力,根据中点电压波动和中点电流的方向,选择不同的共模电压抑制方案。这种混合方案在抑制共模电压的同时,又增强了中点电压调节能力。大量的实验结果验证了所提方案的有效性和正确性。

compared with two lvel ivete,T-ype teevee ivreter has the avanages of hgher sisoia output 0otse wvelrm and bter harmonic carceries which makes it widely sudieded and aplede with smal wectoes a5 cene aspace vector pulse with mdultion (SPWM)method based on tw.e iverter for Tope thee level iverte ipresete in 60 coriatre ytm.in order to upes the cmmom.moe votage,vecters with smal cmmomrmn voltage are used to synthesize the central small vectors withlarge;common-mode voltage,and the common-mode voltage ampitude is lmied to one sixth of DC bus vltage.Based on the spsn of common mode vltge the nutat:pont vote contol alles of dre schemes are sudie and dferet scemes are slete ecorng t0 nutr pont ote futaton and nutalpointn urent decion This hybnd mehod can not only spes comorm Votage,but also enhance the neutral point vltge contol ailly Abundant exeriment resuts verify the effectiveness and correctness of the proposed methods.