This article presents the use of model predictive control (MPC) in multilevel inverters for some applications, such as, first, wind generation and, second, photovoltaics, showing that the particular restrictions of each of them can be very easily included in the control algorithm, which is an important advantage of this technique. Another application is in modular multilevel cascaded converters, where it is demonstrated that MPC can operate with very few calculations and fixed switching frequency. The second part of this article is dedicated to comparing MPC with linear control and pulsewidth modulation for multilevel inverters. The main comparison criteria are the switching losses, the distortion in the load current, and the number of commutations. The main conclusion is that MPC is a competitive alternative to linear control for application in multilevel inverters.
{"title":"Model Predictive Control in Multilevel Inverters Part II: Renewable Energies and Grid Applications","authors":"Margarita Norambuena;Andres Mora;Cristian Garcia;Jose Rodriguez;Mokhtar Aly;Fernanda Carnielutti;Javier Pereda;Cristian Castillo;Zhenbin Zhang;Venkata Yaramasu;Luca Tarisciotti;Yafei Yin","doi":"10.1109/OJIA.2024.3460668","DOIUrl":"10.1109/OJIA.2024.3460668","url":null,"abstract":"This article presents the use of model predictive control (MPC) in multilevel inverters for some applications, such as, first, wind generation and, second, photovoltaics, showing that the particular restrictions of each of them can be very easily included in the control algorithm, which is an important advantage of this technique. Another application is in modular multilevel cascaded converters, where it is demonstrated that MPC can operate with very few calculations and fixed switching frequency. The second part of this article is dedicated to comparing MPC with linear control and pulsewidth modulation for multilevel inverters. The main comparison criteria are the switching losses, the distortion in the load current, and the number of commutations. The main conclusion is that MPC is a competitive alternative to linear control for application in multilevel inverters.","PeriodicalId":100629,"journal":{"name":"IEEE Open Journal of Industry Applications","volume":"5 ","pages":"414-427"},"PeriodicalIF":7.9,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10680135","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142253441","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Multilevel inverters (MLIs) have lately become important due to their extended application to electrical transmission and distribution systems. At the same time, the control and modulation of MLIs are especially challenging due to the high number of switching states, many of them redundant in terms of output voltage generation, and their nonlinear characteristics. In order to ease their implementation in real environment, model predictive control (MPC) is often considered, where the main control targets are: 1) to generate a the desired output current and 2) to keep the internal converter capacitor voltages at their reference value. However, a major issue with the implementation of MPC in MLIs is that the number of calculations to be done online increases dramatically with the number of levels, making it almost impossible to apply MPC in some practical cases. For these reasons, one of the main research trend in MPC for MLIs is to provide an algorithm which can reduce the computational burden necessary to operate the control. The article proposes a review of such control techniques. Starting from the basic MPC implementation and using a flying capacitor converter as an example the article review the basic strategies to avoid calculating the weighting factor in the cost function, simplifying the implementation. Also, methods to reduce the number of calculations necessary to implement MPC are shown and applied to cascaded H-bridge converters. These techniques allow to keep an high load current quality while reducing more than 95% in the number of calculations necessary to implement the control. Finally, other operation improvements of MPC are also included, such as fixed switching frequency operation and multistep MPC, reaching an important performance improvement compared to the basic MPC strategy.
{"title":"Model Predictive Control in Multilevel Inverters Part I: Basic Strategy and Performance Improvement","authors":"Cristian Garcia;Andres Mora;Margarita Norambuena;Jose Rodriguez;Mokhtar Aly;Fernanda Carnielutti;Javier Pereda;Pablo Acuna;Ricardo Aguilera;Luca Tarisciotti","doi":"10.1109/OJIA.2024.3460669","DOIUrl":"10.1109/OJIA.2024.3460669","url":null,"abstract":"Multilevel inverters (MLIs) have lately become important due to their extended application to electrical transmission and distribution systems. At the same time, the control and modulation of MLIs are especially challenging due to the high number of switching states, many of them redundant in terms of output voltage generation, and their nonlinear characteristics. In order to ease their implementation in real environment, model predictive control (MPC) is often considered, where the main control targets are: 1) to generate a the desired output current and 2) to keep the internal converter capacitor voltages at their reference value. However, a major issue with the implementation of MPC in MLIs is that the number of calculations to be done online increases dramatically with the number of levels, making it almost impossible to apply MPC in some practical cases. For these reasons, one of the main research trend in MPC for MLIs is to provide an algorithm which can reduce the computational burden necessary to operate the control. The article proposes a review of such control techniques. Starting from the basic MPC implementation and using a flying capacitor converter as an example the article review the basic strategies to avoid calculating the weighting factor in the cost function, simplifying the implementation. Also, methods to reduce the number of calculations necessary to implement MPC are shown and applied to cascaded H-bridge converters. These techniques allow to keep an high load current quality while reducing more than 95% in the number of calculations necessary to implement the control. Finally, other operation improvements of MPC are also included, such as fixed switching frequency operation and multistep MPC, reaching an important performance improvement compared to the basic MPC strategy.","PeriodicalId":100629,"journal":{"name":"IEEE Open Journal of Industry Applications","volume":"5 ","pages":"428-441"},"PeriodicalIF":7.9,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10679905","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142253442","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This article presents the development of an electric motor with the novel distributed high-density (DHD) winding technology. The DHD winding technology utilizes round wires instead of bar wires. Unlike conventional round-wire winding technique (shed winding), the wires are orderly positioned in the slots in the DHD winding technology, resulting in high fill factor and high efficiency. The implementation of a stator with the DHD winding is presented which utilizes state-of-the-art coil winding and assembly processes. To compare against existing stator designs, a 100 kW, 800 V, and 15 000 RPM propulsion motor is tested experimentally to validate the performance of the DHD winding technology. The acoustic noise behavior of the propulsion motor is also characterized experimentally. The motor efficiency with the DHD, hairpin, and shed windings is compared for the same stator geometry using simulation results to demonstrate the performance improvement with the DHD winding technology.
{"title":"A High-Efficiency Propulsion Motor With Distributed High-Density Winding Technology","authors":"Daniele Meanti;Davide Parati;Alexander Allca-Pekarovic;Moien Masoumi;Kumar Rajasekhara;Berker Bilgin","doi":"10.1109/OJIA.2024.3457505","DOIUrl":"10.1109/OJIA.2024.3457505","url":null,"abstract":"This article presents the development of an electric motor with the novel distributed high-density (DHD) winding technology. The DHD winding technology utilizes round wires instead of bar wires. Unlike conventional round-wire winding technique (shed winding), the wires are orderly positioned in the slots in the DHD winding technology, resulting in high fill factor and high efficiency. The implementation of a stator with the DHD winding is presented which utilizes state-of-the-art coil winding and assembly processes. To compare against existing stator designs, a 100 kW, 800 V, and 15 000 RPM propulsion motor is tested experimentally to validate the performance of the DHD winding technology. The acoustic noise behavior of the propulsion motor is also characterized experimentally. The motor efficiency with the DHD, hairpin, and shed windings is compared for the same stator geometry using simulation results to demonstrate the performance improvement with the DHD winding technology.","PeriodicalId":100629,"journal":{"name":"IEEE Open Journal of Industry Applications","volume":"5 ","pages":"391-404"},"PeriodicalIF":7.9,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10670318","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142176889","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-10DOI: 10.1109/OJIA.2024.3430047
David Klink;Matthew J. Bagnara;Greg Heins;Behrooz Bahrani
Permanent magnets are popular for electric vehicle rotors due to their high energy density, making them excellent candidates for high-torque and high-speed machines. The downside of a permanent magnet machine is the inability to regulate the rotor field, creating nonideal behavior during high-speed or low-load operation, and potentially resulting in high currents and voltages in fault conditions. Several solutions to this have been explored, such as interior permanent magnet (combined reluctance and permanent magnet rotors), “hybrid” wound field and permanent magnet rotors, and variable flux machines with in-situ magnetization control or mechanical field weakening. This article proposes a novel method of regulating the air gap in axial flux machines, allowing for a low-cost mechanism allowing two degree of freedom operation without additional power electronics or modifications to the magnetics. The proposed method uses stacked linear springs to create a nonlinear bias against the attraction force, and then leverages direct axis current to control the air gap. The ideal constant current optimized field weakening spring curve is presented and the proposed concept is experimentally validated on a single-stator single-rotor axial flux machine.
{"title":"Permanent Magnet Rotor Flux Linkage Control Through Direct Axis Field Amplification","authors":"David Klink;Matthew J. Bagnara;Greg Heins;Behrooz Bahrani","doi":"10.1109/OJIA.2024.3430047","DOIUrl":"https://doi.org/10.1109/OJIA.2024.3430047","url":null,"abstract":"Permanent magnets are popular for electric vehicle rotors due to their high energy density, making them excellent candidates for high-torque and high-speed machines. The downside of a permanent magnet machine is the inability to regulate the rotor field, creating nonideal behavior during high-speed or low-load operation, and potentially resulting in high currents and voltages in fault conditions. Several solutions to this have been explored, such as interior permanent magnet (combined reluctance and permanent magnet rotors), “hybrid” wound field and permanent magnet rotors, and variable flux machines with in-situ magnetization control or mechanical field weakening. This article proposes a novel method of regulating the air gap in axial flux machines, allowing for a low-cost mechanism allowing two degree of freedom operation without additional power electronics or modifications to the magnetics. The proposed method uses stacked linear springs to create a nonlinear bias against the attraction force, and then leverages direct axis current to control the air gap. The ideal constant current optimized field weakening spring curve is presented and the proposed concept is experimentally validated on a single-stator single-rotor axial flux machine.","PeriodicalId":100629,"journal":{"name":"IEEE Open Journal of Industry Applications","volume":"5 ","pages":"369-380"},"PeriodicalIF":7.9,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10670564","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142165099","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-03DOI: 10.1109/OJIA.2024.3451990
Nicolas E. Lima Baschera;Alessandro Lidozzi;Giuseppe Zummo;Luca Saraceno;Fabio Riccardi;Fernando Ortenzi;Marco di Benedetto;Luca Solero
This article deals with a comprehensive analysis and performance evaluation of a fully integrated two-phase cooling system for power converters. A suitable test bed has been properly manufactured to perform the experimental campaign for the evaluation of the benefits and to deploy a dedicated management procedure of the two-phase cooling. The system is tested under real operating conditions, in which the system is employed for cooling a 1200-V 100-A insulated-gate bipolar transistor (IGBT) power module of an inverter controlling a permanent magnet synchronous machine. The experimental results show the inverter temperature behavior in start-up for different flow rates of coolant and different temperatures of the fluid on the secondary system. In the steady-state operation, using lower coolant flow rates in the primary circuit achieved equal or even better cooling for the IGBT module compared with higher flow rates. With respect to traditional cooling approaches, the proposed arrangement allows a greater extraction of the heat at a very low flow rate of the cooling fluid, even with standard industrial grade heat sinks, which motivates the use of this cooling technology for the next generation of power electronics converters.
{"title":"Advances in Two-Phase Cooling for Next Power Electronics Converters","authors":"Nicolas E. Lima Baschera;Alessandro Lidozzi;Giuseppe Zummo;Luca Saraceno;Fabio Riccardi;Fernando Ortenzi;Marco di Benedetto;Luca Solero","doi":"10.1109/OJIA.2024.3451990","DOIUrl":"10.1109/OJIA.2024.3451990","url":null,"abstract":"This article deals with a comprehensive analysis and performance evaluation of a fully integrated two-phase cooling system for power converters. A suitable test bed has been properly manufactured to perform the experimental campaign for the evaluation of the benefits and to deploy a dedicated management procedure of the two-phase cooling. The system is tested under real operating conditions, in which the system is employed for cooling a 1200-V 100-A insulated-gate bipolar transistor (IGBT) power module of an inverter controlling a permanent magnet synchronous machine. The experimental results show the inverter temperature behavior in start-up for different flow rates of coolant and different temperatures of the fluid on the secondary system. In the steady-state operation, using lower coolant flow rates in the primary circuit achieved equal or even better cooling for the IGBT module compared with higher flow rates. With respect to traditional cooling approaches, the proposed arrangement allows a greater extraction of the heat at a very low flow rate of the cooling fluid, even with standard industrial grade heat sinks, which motivates the use of this cooling technology for the next generation of power electronics converters.","PeriodicalId":100629,"journal":{"name":"IEEE Open Journal of Industry Applications","volume":"5 ","pages":"381-390"},"PeriodicalIF":7.9,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10663977","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142176890","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-12DOI: 10.1109/OJIA.2024.3441308
Filipe Pinarello Scalcon;Gaoliang Fang;Cesar José Volpato Filho;Sumedh Dhale;Babak Nahid-Mobarakeh
The large dc-link current is a known issue in switched reluctance motor (SRM) drives, which often demand the use of a bulky dc-link capacitor. However, control techniques can be designed and optimized to lessen this issue. In this context, this article proposes the optimization of analytical torque sharing functions (TSFs) for dc-link current reduction in SRMs. Initially, the analytical TSFs are described, and the importance of adequate parameter selection is highlighted. Next, an optimization procedure based on the nondominated sorting genetic algorithm II is proposed to determine the optimal turn- on