FCS-MPC and Observer Design in the dq Synchronous Frame: An Experimental Validation

The addition of an output LC filter to a voltage source inverter (VSI) allows the generation of high-quality output voltages with reduced harmonic distortion content. For this reason, this topology is widely used for uninterruptible power supply (UPS) applications. To control this system, finite control set model predictive control (FCS-MPC) has been assessed in previous research with promising results. In this paper, the dq-synchronous reference frame (dq-SRF) formulation of FCS-MPC and a state observer for an UPS system are presented and experimentally validated. The advantage of this proposal lies in the simplification of the observer design by considering a deadbeat observer along with the addition of a low-pass filter. In this way, the observer bandwidth is simply determined by the cutoff frequency of the low-pass filter. Simulation and experimental results are compared to assess the performance of the proposed solution.