scholarly journals Finite Control Set—Model Predictive Control with Non-Spread Spectrum and Reduced Switching Frequency Applied to Multi-Cell Rectifiers

Energies ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 6045
Author(s):  
Eduardo Espinosa ◽  
José Espinoza ◽  
Pedro Melín ◽  
Jaime Rohten ◽  
Carlos Baier ◽  
...  

Multi-cell converters are widely used in medium-voltage AC drives. This equipment is based on power cells that operate with low-voltage-rating semiconductors and require an input multipulse transformer. This transformer cancels the low-frequency current harmonics generated by the three-phase diode-based rectifier. Unfortunately, this transformer is bulky, heavy, expensive, and does not extend the existing power cell (three-phase rectifier—Direct Current (DC) voltage-link—single-phase inverter) to the transformer. In this study, a harmonic cancelation method based on finite control set-model predictive control (FCS–MPC), extending the power cell’s modularity to the input transformer. On the other hand, it considers treating the two disadvantages of the FCS–MPC: High switching frequency and spread spectrum. The details were developed in theory and practice to obtain satisfactory experimental results.

2021 ◽  
Author(s):  
Jaksa Rubinic

This thesis proposes a new predictive control strategy to achieve fixed-switching frequency operation for a neutral-point clamped (NPC) inverter. The classical fixed-sampling frequency finite control-set model predictive control (FSF-FCS-MPC) operates with variable switching frequency, and thus produces spread-spectrum in an output current. The classical method also suffers from high computational complexity as the number of converter voltage levels increases. To overcome these issues, a high performance variable sampling frequency finite control-set model predictive control (VSF-FCS-MPC) strategy is proposed to control the power converters. The proposed control technique combines the advantages of space vector modulation (SVM) with a newly introduced mechanics to determine the appropriate sampling frequency. With these features the major requirements such as balancing of DC-link capacitor voltages, switching frequency minimization and common-mode voltage mitigation have been achieved with simultaneous elimination of even-order and inter-harmonics in the load current harmonic spectrum. The VSF-FCS-MPC strategy for current control with decoupled active/reactive power regulation of grid-connected multilevel converter was also analyzed. Moreover, a novel DC-link voltage balancing technique is presented which eliminates the need for balancing the capacitor voltages through cost function, and thus alleviates the weighting factor design. An introduction of SVM highly reduces the calculation time by considering only adjacent vectors, rendering FCS-MPC more suitable for implementation with multi-level converters with a number of voltage levels higher than three. Finally, the proposed control technique has been validated through simulation and experimental verification and a detailed comparison of VSF-FCS-MPC with FSF-FCS-MPC and SVM is presented


2019 ◽  
Vol 9 (17) ◽  
pp. 3513 ◽  
Author(s):  
Mohammed Alhasheem ◽  
Frede Blaabjerg ◽  
Pooya Davari

Finite control set model predictive control (FCS-MPC) methods in different power electronic applications are gaining considerable attention due to their simplicity and fast dynamics. This paper introduces an assessment of the two-level three-phase voltage source converter (2L-VSC) utilizing different MPC schemes with and without a modulation stage. In order to perform such a comparative evaluation, 2L-VSC efficiency and total harmonics distortion of the voltage (THDv) have been investigated, when considering a linear load. The results demonstrate the performance of different MPC algorithms through an experimental verification on a Danfoss converter, and a set of analyses have been studied using the PLECS and MATLAB/SIMULINK together. It can be concluded that a comparable performance is achieved by using conventional MPC (CMPC), improved MPC (IMPC), periodic MPC (PMPC), and MPC scheme with modulator (M 2 PC) controllers. The assessment is critical to classify the strategies as mentioned earlier according to their efficiency. Furthermore, it gives a thorough point of view on which algorithm is suitable for the grid-forming applications.


Solar Energy ◽  
2019 ◽  
Vol 189 ◽  
pp. 57-66 ◽  
Author(s):  
R.B.A. Cunha ◽  
R.S. Inomoto ◽  
J.A.T. Altuna ◽  
F.F. Costa ◽  
S.G. Di Santo ◽  
...  

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