The three major approaches for current-regulated inverters are ramp comparison, hysteresis control, and predictive current control. From these three, predictive current control offers the potential for achieving more precise current control with minimum distortion and harmonic noise. But, the predictive method is difficult to implement and needs more computational burden. The traditional predictive current controller has a poor performance under component parameter variations, and is less robust to filters inductance mismatch. A robust predictive current control strategy was proposed and studied. Both simulations and experimental results show that the proposed method is much more robust to parameter mismatch than the traditional one.Index Terms-Grid connected inverter, predictive control, pulse width modulated (PWM), robust control, single phase.

No abstract

Peak-current-mode (PCM) control is a widely used method to control switched-mode converters. Most often an input filter is necessary to meet electromagnetic interference requirements. The input filter can cause instability and degradation of input and output dynamics if not properly designed. The input filter design from the output dynamics viewpoint has been addressed in numerous papers, resulting in well-agreed results in the case of direct duty-ratio control. The same methods and criteria have also been applied to PCM control, but the results have turned out to be conflicting. This paper shows that the adverse effect of the input filter on the output performance of a peak-current-controlled buck converter in continuous inductor-current mode is insignificant. The input performance is, however, significantly affected, necessitating the use of proper damping. It is also shown that the instability is caused solely by the instability of the input filter under negative incremental resistance. The methods used are unified in nature, but the results obtained in this study cannot be generalized to be valid for types of converters other than a buck converter.Index Terms-Buck converter, continuous inductor current mode, input filter, input and output dynamics, peak-current-mode control.

No abstract

This paper will study the input dynamics of a buck type converter with input filter using voltage-mode and current-mode control at continuous inductor-current-mode. The relevant transfer functions are derived first without input filter and the effect of input filter is added by means of circuit theoretical manipulations. The transfer functions are analyzed in frequency domain. The effect of switching frequency as well as the propagation of rapidly varying load current pulses will be studied using MatlabTM. It is evident that the dynamic behavior of Telecom load system in the respect of EMC and the required dynamics of the down-stream converter can cause severe problems, if the input filtering and controller design is not carefully considered.