Improved control strategy to eliminate the harmonic current components for single-phase PWM current source inverter

The single-phase PWM current source inverter has many advantages for utility-interactive power systems. It is suitable especially for the noninsulated type utility-interactive topology which is widely used for residential photovoltaic generating systems in Japan. However, this type of inverter has a significant disadvantage, that is to say, the output current of the inverter has large harmonic components when its smoothing reactor is not large enough to eliminate the ripple component of its current. This paper presents a new control strategy to reduce the harmonic component of the single-phase PWM current source inverter sufficiently, even when the ripple current in the smoothing reactor is large. The principle of the proposed control strategy for this inverter system is described, and its simulation results are introduced and evaluated.