Papers by mauricio angulo
Abstract Multilevel inverters have emerged as the state of the art power conversion systems for h... more Abstract Multilevel inverters have emerged as the state of the art power conversion systems for high power medium voltage applications. However, like most power converter families, these inverters are nonlinear systems with dead times, voltage drops across the power semiconductors, load and supply dependent DC-links, that all together can generate considerable low frequency voltage and current distortion affecting negatively the quality of important variables of the global process powered by the inverter. In high power ...
Like most power converter topologies, multilevel inverters are controlled with modulation techniq... more Like most power converter topologies, multilevel inverters are controlled with modulation techniques that are conceptually based on nonlinear waveform synthesis assuming constant dc-link voltages. However, real applications have load and supply dependent dc-links that usually present important low frequency ripple, which is also modulated and transmitted to the load, generating undesirable low frequency voltage and current distortion. This paper introduces a simple but effective dc-link ripple feedforward strategy into traditional carrier-based modulation techniques. The dc-link ripples are measured and used to modify the carriers or the reference directly in the modulation stage. Simulation and experimental results show the accuracy of the proposed method, eliminating low order harmonics in the load current.
Abstract Cascaded H-bridge multilevel inverters are commonly controlled using multicarrier Phase-... more Abstract Cascaded H-bridge multilevel inverters are commonly controlled using multicarrier Phase-Shifted PWM, since it allows an even power distribution among the converter power cells, which can lead to lower harmonic distortion in the input current if an adequate transformer is used. However it is known that other multicarrier methods, like Phase Disposition PWM (PD-PWM) have better output voltage quality with lower distortion. Nevertheless, when used with cascaded inverters, this method produces uneven usage of ...
IEEE Transactions on Power Electronics, 2008
Novel simple indirect control concepts for an active power filter (APF) application are proposed ... more Novel simple indirect control concepts for an active power filter (APF) application are proposed here. The concepts are exemplarily presented to control a modified APF structure. The main advantage over other control strategies is the achieved excellent simplicity-to-performance ratio. The proposed control strategies are based on the concept of virtual impedance emulation to provide high power factor in a system. To validate the operating principle, a single-phase low-power prototype has been built and experimentally tested. This prototype operates at a remarkably low switching frequency of 5 kHz and is digitally controlled by a digital signal processor.
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Papers by mauricio angulo