《《Model Predictive Control of an Inverter With Output LC Filter for UPS Applications》.pdf

IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, VOL. 56, NO. 6, JUNE 2009 1875 Model Predictive Control of an Inverter With Output LC Filter for UPS Applications Patricio Cortés, Member, IEEE, Gabriel Ortiz, Juan I. Yuz, Member, IEEE, José Rodríguez, Senior Member, IEEE, Sergio Vazquez, Member, IEEE, and Leopoldo G. Franquelo, Fellow, IEEE Abstract—The use of an inverter with an output LC filter allows bank resonant filters [10], [11], and repetitive-based controllers for generation of output sinusoidal voltages with low harmonic [12], [13]. Some tuning strategies have been presented, includ- distortion, suitable for uninterruptible power supply systems. ing H-infinity control design [14]. In most of these schemes, the However, the controller design becomes more difficult. This paper presents a new and simple control scheme using predictive control output voltage and one of two currents are used by a cascaded for a two-level converter. The controller uses the model of the control considering outer and inner control loops, with linear system to predict, on each sampling interval, the behavior of the or nonlinear controllers, to generate the reference voltages and output voltage for each possible switching state. Then, a cost by an external modulator to generate the firing pulses for the function is used as a criterion for selecting the switching state power semiconductors. that will be applied during the next sampling interval. In addi- tion, an observer is used for load-current estimation, enhancing Predictive control appears as an attractive alternative for the the behavior of the proposed controller without increasing the control o