A new digital zero average current error control algorithm for inverters

Inverter performance is typically measured against its ability to produce a high fidelity output sinusoidal waveform with narrow band switching frequency and good transient response. For this purpose, pulse-width modulation techniques are used to generate the required control signals for the inverter semiconductor switches. Current control voltage-source inverters can be realized using one of the recently proposed zero average current error (ZACE) techniques based on analogue technology. A new and improved algorithm that belongs to the family of ZACE methods suitable for digital technology is proposed in this paper. Advantages include a more robust algorithm with quicker computation allowing fast response and higher switching frequency from a digital signal processor. The effectiveness of the new current control algorithm is demonstrated through simulations first. Experimental results taken from a low power laboratory prototype are also presented to verify the theoretical considerations.