Performance Comparison of Voltage Mode Control and Current Mode Control of a Three-Phase PWM Rectifier based on a Dual SISO Model

The challenge in controlling a three-phase PWM rectifier mainly arises from the fact that the state-space-averaged model reported in literature has a multi-input multi-output (MIMO) non-linear structure and furthermore exhibits non-minimum phase feature. Recently, a dual single-input single-output (SISO) model developed for the rectifier showed that the dynamics of the d-axis is similar to that of a traditional dc-dc boost converter. This finding makes it possible to extend the control design and system analysis techniques of dc-dc converters to these rectifiers. In this paper, the well-documented techniques in dc-dc converters namely, voltage and current-mode control techniques, are applied and investigated for a three phase rectifier. The steady-state and transient performances for step changes in output voltage reference, dc load, and supply voltage are experimentally investigated and the results obtained with the two control methods are compared. Experimental results suggest that better performance can be achieved with the current mode controller. The results also further justify the validity of the dual SISO model