Browsing by Author "Aguilera, Ricardo P."

Modular multilevel matrix converters stand out for their performance in ac–ac high-power conversion. However, they require multiple control loops to govern the currents from both ac ports, the internal circulating currents, and the capacitor voltages. This article proposes a computationally efficient model predictive control (MPC) strategy based on a new converter modeling to exploit the phase-shifted pulsewidth modulation working principle fully, achieving four improvements: 1) control unification of both ac-ports currents, circulating currents, and capacitor voltages; 2) constrained optimization to safeguard the converter limits; 3) computational burden reduction and high scalability compared to standard MPC strategies; and 4) wide frequency operation with fast closed-loop transient responses, low harmonic distortion, and fixed switching frequency.

This article proposes a novel dual-stage control strategy for a flying capacitor converter. During transients, the proposed control scheme applies finite-control-set model predictive control to drive the system close to the desired reference, including all the known nonlinearities of the system in the converter model. When the converter state is in a neighborhood of the reference, the dual-stage controller switches to a pulsewidth modulation based linear controller with an integral action. In this case, the linear controller is reformulated in its feedback form. Thus, the internal linear controller states can be updated based on the actual input applied by the predictive controller. This allows the dual-stage controller to achieve a smooth transition when commuting between controllers and a zero-steady-state error even when load parameter errors are present. Experimental results are provided to verify the effectiveness of the proposed dual-stage controller.