The growth in the energy demand, caused by the continuous increase of the industrial plants capacity, has been demanding higher voltage levels of the static converters applied to the industrial equipment drives, such as motors, rolling mills, pumps, fans and compressors. This increase ends up reaching the physical limit of the power semiconductor, making it impossible to drive equipment with conventional converters connected directly to the medium voltage. Due to this technological deficit, one of the proposals in the literature is the usage of the Cascaded H-Bridge Multilevel Converter (CHB). However, the CHB topology has an operational limitation when using the Back-to-Back (B2B) configuration, since some switching states result in short circuits between the multiple isolated capacitors. The main objective of this article is to propose a high-frequency switching strategy based on the concepts of model predictive control capable of eliminating the capacitor short-circuit stages without losing the controllability and quality of current waveforms and converter voltage.

The design and analysis of the modular multilevel converter (MMC) are usually performed with simulation softwares in an interactive mode. Each parameter is individually set in order to analyze the effect on the converter output, which in turn, demands a lot of time of the user. In this context, this paper proposes a methodology based on Double Fourier Transform so as to provide support to the parameterization of modular multilevel converter (MMC). This methodology allows the designer to choose the appropriate converter, considering its main specifications, from analysis of the results to variations in the amplitude and frequency modulation rates as well as the number of modules used. The proposed methodology was developed in MATLAB software, computationally validated by electromagnetic transient analysis software PSCAD / EMTDC, and experimentally certified through implementation in FPGA Xilinx Spartan-3.

The growth in the energy demand, caused by the continuous increase in industrial plants capacity, has been demanding higher voltage levels of the static converters applied to the industrial equipment drives, such as motors, rolling mills, pumps, fans and compressors. This increase ends up reaching the power semiconductor physical limit, making it impossible to drive equipment with conventional converters connected directly to the medium voltage. Due to this technological deficit, one of the proposals in the literature is the usage of the Cascaded H-Bridge Multilevel Converter (CHB). However, the CHB topology has an operational limitation when using the Back-to-Back (B2B) configuration, since some switching states result in short circuits between the multiple isolated capacitors. The main objective of this article is to propose a high-frequency switching strategy based on the concepts of model predictive control capable of eliminating the capacitor short-circuit stages without losing the controllability and quality of current waveforms and converter voltage.

This paper proposes a predictive current control (PCC) strategy with a field orientation applied on a three-level neutral point clamped (NPC) inverter to drive a three-phase induction motor. It was used the optimal switching vector (OSV) strategy, which is most suitable for power electronics. The field orientation, along with a rotor flux estimation, made it possible to implement a control loop measuring only stator voltage, stator current and rotor speed. The simulation results showed that the average estimated rotor flux error was 0.03%, the total harmonic distortion (THD) for the stator current was 9.29%, and the average stator current error was 5.82%. The proposed model proved to be a viable option to industrial plants, especially when compared with classical controllers.

This paper proposes a new cascaded multilevel converter topology based on three-phase H bridge cells with a common DC-link structure. The proposed multilevel converter topology main advantages, compared with literature renowned multilevel converters topologies, are discussed in the paper, such as modularity, construction, implementation cost, and DC voltage ripple mitigation. Despite presenting an elementary structure and easy implementation, the use of classic PWM switching strategies is not feasible for this topology, causing the appearance of several short-circuit states between its capacitors. Thus, a graph theory algorithm combined with a model predictive control is also proposed in this work to identify and avoid the new cascaded multilevel converter short-circuit switching states and, concomitantly, guaranteeing the converter output power quality. In order to validate the presented topology applicability, a low voltage synchronous static compensators (STATCOM) with an optimal switching vector model predictive control (OSV-MPC) is implemented in a hardware-in-the-loop platform. The real-time experimental results prove the proposed multilevel topology and the OSV-MPC control strategy effectiveness.

This paper proposes a new cascaded multilevel converter topology, presenting some inherent advantages to its construction and implementation cost when compared to the most used multilevel converters in the literature. As a disadvantage, the new topology presents several short-circuit states, which, if used with classic PWM switching strategies, can cause damage to internal components making its implementation unfeasible. Thus, an analysis based on Graph Theory combined with a model predictive control is proposed in order to identify and avoid all possible short-circuit states of the proposed converter The proposed topology is applied to a STATCOM by means of an Optimal Switching Vector Model Predictive Control (OSV-MPC) in order to prove its usability. Simulation results in Simulink MATLAB of such application are also presented.