Model predictive control-a simple and powerful method to control UPS inverter applications with output LC filter

The use of an inverter with an output LC filter allows for generation of sinusoidal voltages with low harmonic distortion. Several control schemes have been proposed for the control of three-phase inverter. A Model Predictive Control scheme is used for voltage control of a three-phase inverter with output LC filter. The controller uses a discrete-time model of the system to predict the behavior of the output voltage for all possible switching states generated by the inverter. The voltage vector that minimizes a cost function is chosen and its corresponding switching state is applied during the next sampling instant. The cost function used in this work evaluates the output voltage error at the next sampling time and used as a criterion of system performance. The performance of the proposed predictive control method is compared with hysteresis and pulsewidth modulation control under linear and nonlinear loads, using Matlab/Simulink tools. The results show that the predictive method controls very effectively the output voltage and performs very well compared with the classical solutions.