1 research outputs found
Nonlinear Control of Single-Phase PWM Rectifiers with Inherent Current-Limiting Capability
In this paper, a nonlinear controller with a currentlimiting
property is proposed to guarantee accurate dc output
voltage regulation and unity power factor operation for singlephase
PWM rectifiers without the need of a phase-locked-loop
(PLL). The proposed current-limiting controller is fully independent
of the system parameters and can guarantee asymptotic
stability and convergence to a unique solution for the closedloop
system using nonlinear control theory. Without requiring
the instantaneous measurement of the grid voltage, a PLL,
an external limiter or a saturation unit, the proposed strategy
guarantees that the input current of the rectifier will always
remain below a given value. An analytic framework for selecting
the controller parameters is also presented to provide a complete
controller design procedure and it is also proven that the currentlimiting
property is maintained even when the grid voltage
drops. Extensive experimental results are presented to verify
the proposed controller when the load changes, the reference
dc output voltage changes and the grid voltage drops