A new digital control method for a voltage source inverter to compensate for imbalance of output voltage

摘要

This paper provides a new signal compensation method for digital inverters, which is aimed at improving the voltage source inverter. Because of the non-ideal characteristics of components of the inverter (e.g., metal oxide semiconductor field-effect transistor module), the output voltage is unequal at positive and negative half cycles. This will result in inductive load saturation, and the switches will be damaged. The method proposed in this paper utilizes a combination of pulse signal and reference signal for adjusting the height and the width of pulse signal, with small direct current offset compensated by the average voltage of the signal. This method can also be adopted in a built-in, low-resolution pulse width modulation digital controller, which has advantages such as automatic compensation of output voltage and low cost.