电力逆变器调制理论的扩展研究

Extended Modulation Theory for Power Inverters

调制理论是电力变流器分析的有效工具,但是目前调制理论提供的公式在数量和灵活性上具有局限性,难以适应工作在不同控制方式下的逆变器分析。对电力变流器调制理论进行扩展研究,推导出调制理论的扩展公式,并以三相六脉动逆变器为例,详细分析逆变器在相控和脉宽调制(pulse width modulation,PWM)控制方式下的所有工作状态,同时推导出其完整的调制公式,并通过物理实验和软件仿真进行验证。推导出的扩展调制公式适用于采用不同控制方式的逆变器,可以从逆变器任意一侧的电压(或电流)直接推导出另一侧的电压(或电流),从而为电力逆变器的建模和分析提供极大灵活性。

Modulation theory is a powerful tool for power converter analysis. However, present modulation theory only provides limited equations and lack of flexibility for inverters under different control modes. Thus an extended modulation theory was proposed in the paper. Furthermore, extended equations were provided. The paper took a three-phase six-pulse inverter as an example, and discussed all the states of inverters under phase control and pulse width modulation （PWM） control modes in detail, and deduced complete modulation equations which are further validated by physical experiment and software simulation. The proposed equations can be used to deduce the voltage or current of arbitrary side from those of another side of an inverter under different control modes, and provide invaluable flexibility for the modeling and analysis of power inverters.