Control of a PWM converter in different input voltage conditions

Abstract

A control scheme of a three-phase voltage-source PWM power converter available for the condition of different input voltages is proposed in this paper. From the steady-state model of the power converter, the effect caused by the input voltage on the control of the input current is analyzed from the point of the linear controllability of the input current. Sufficient voltage level of the DC link to control the input current linearly is then analytically determined. The effect of the different input voltage on the DC link voltage control with a fixed-gain controller is analyzed and a simple but effective online gain tuning algorithm is proposed to obtain the optimal regulation of the link voltage. In conclusion, the validity of the proposed control scheme is proved by the experimental results.