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This paper presents a new transformerless multilevel converter topology. This power converter is owned by Nidec ASI and is implemented in the medium voltage drive SILCOVERT-FH. The topology is composed by the series association of two Macro-Cells, which can be extended in order to increase the number of output levels, and one external Selector Cell. Among the advantages, the number of devices directly connected in series does not depend on the DC bus voltage. The same devices can be used in 5L and 7L configurations to address the 4.16 and 6.6 kV applications, which is a significant advantage from the industrialization point of view. Moreover, due to its inherent feature, the Zero-Crossing is performed naturally at Zero-Voltage Switching (ZVS) on the Selector Cell. Experimental and simulation results are shown in order to validate the performance of the converter, highlighting the main benefits and features of the proposed topology.
Jaime Wladimir Zapata; Gianluca Postiglione; Daniele Falchi; Giovanni Borghetti; Thierry A. Meynard; Guillaume Gateau. Multilevel Converter for 4.16- and 6.6-kV Variable Speed Drives. IEEE Transactions on Power Electronics 2020, 36, 3172 -3180.
AMA StyleJaime Wladimir Zapata, Gianluca Postiglione, Daniele Falchi, Giovanni Borghetti, Thierry A. Meynard, Guillaume Gateau. Multilevel Converter for 4.16- and 6.6-kV Variable Speed Drives. IEEE Transactions on Power Electronics. 2020; 36 (3):3172-3180.
Chicago/Turabian StyleJaime Wladimir Zapata; Gianluca Postiglione; Daniele Falchi; Giovanni Borghetti; Thierry A. Meynard; Guillaume Gateau. 2020. "Multilevel Converter for 4.16- and 6.6-kV Variable Speed Drives." IEEE Transactions on Power Electronics 36, no. 3: 3172-3180.
Photovoltaic (PV) systems composed by two energy conversion stages are attractive from an operation point of view. This is because the maximum power point tracking (MPPT) range is extended, due to the voltage decoupling between the PV system and the dc-link. Nevertheless, the additional dc-dc conversion stage increases the volume, cost and power converter losses. Therefore, central inverters based on a single-stage converter, have been a mainstream solution to interface large-scale PV arrays composed of several strings connected in parallel made by the series connections of PV modules. The concept of partial power converters (PPC), previously reported as a voltage step-up stage, has not addressed in depth for all types of PV applications. In this work, a PPC performing voltage step-down operation is proposed and analyzed. This concept is interesting from the industry point of view, since with the new isolation standards of PV modules are reaching 1500 V, increasing both the size of the string and dc-link voltage for single-stage inverters. Since grid connection remains typically at 690 V, larger strings impose more demanding operation for single-stage central inverters (required to operate at lower modulation indexes and demand higher blocking voltage devices), making the proposed step-down PPC an attractive solution. Theoretical analysis and an experimental test-bench was built in order to validate the PPC concept, the control performance and the improvement of the conversion efficiency. The experimental results corroborate the benefits of using a PPC, in terms of increasing the system efficiency by reducing the processed power of the converter, while not affecting the system performance.
Jaime Wladimir Zapata; Samir Kouro; Gonzalo Carrasco; Thierry A. Meynard. Step-Down Partial Power DC-DC Converters for Two-Stage Photovoltaic String Inverters. Electronics 2019, 8, 87 .
AMA StyleJaime Wladimir Zapata, Samir Kouro, Gonzalo Carrasco, Thierry A. Meynard. Step-Down Partial Power DC-DC Converters for Two-Stage Photovoltaic String Inverters. Electronics. 2019; 8 (1):87.
Chicago/Turabian StyleJaime Wladimir Zapata; Samir Kouro; Gonzalo Carrasco; Thierry A. Meynard. 2019. "Step-Down Partial Power DC-DC Converters for Two-Stage Photovoltaic String Inverters." Electronics 8, no. 1: 87.
Due to the inherent features of the multilevel Flying Capacitor (FC) converter, the voltages in the capacitors are naturally balanced under phase-shifted pulse width modulation (PS-PWM) techniques. Nevertheless, under certain operation conditions the voltages in the capacitors vary between the commutation cells and an external balancer booster is required. This paper provides a methodology to properly design the balance booster for a FC converter with n-cells based on vectorized models. However, due to the trade-off between balancing speed and power losses, it is difficult to design a balance booster based on speed requirements, and checking loss constraints afterwards may result in a very long iterative process. Designing for losses and checking for speed is a much simpler process and this illustrated here for different types of balance boosters. Some simulations results obtained in PLECS \circledR, are provided to enhance the benefits of the vectorized model for power electronic circuits, and the application to the design of balance boosters is presented.
Jaime Zapata; Thierry Meynard; Guillaume Gateau. Loss-Based Design for Natural Balancing in Multicell Converters using Vectorized Models. 2018 International Symposium on Power Electronics, Electrical Drives, Automation and Motion (SPEEDAM) 2018, 697 -702.
AMA StyleJaime Zapata, Thierry Meynard, Guillaume Gateau. Loss-Based Design for Natural Balancing in Multicell Converters using Vectorized Models. 2018 International Symposium on Power Electronics, Electrical Drives, Automation and Motion (SPEEDAM). 2018; ():697-702.
Chicago/Turabian StyleJaime Zapata; Thierry Meynard; Guillaume Gateau. 2018. "Loss-Based Design for Natural Balancing in Multicell Converters using Vectorized Models." 2018 International Symposium on Power Electronics, Electrical Drives, Automation and Motion (SPEEDAM) , no. : 697-702.
Two-stage photovoltaic (PV) configurations have become increasingly popular due to the decoupling between the inverter dc-link voltage and the PV voltage, adding flexibility to extend the MPPT range. However, the additional dc-dc converter increases the power converter losses. The concept of partial power converters (PPC), which reduce the amount of power handled by the dc-stage can mitigate this effect. However, the type of topology, its power and voltage rating, efficiency, and operating range can vary significantly depending on the function (boosting or reducing voltage) and type of PV application and scale (micro-, string- or multi-sting inverter). This paper analyses of the possible configuration of connections of PPC depending on the application and scale of the PV system, and introduces a new buck-type PPC. Three solutions for practical PV systems are further elaborated, including experimental validation. Results show that the PPC concept greatly improves the overall PV system efficiency with the added benefit that the dc-dc stage power ratings achieved are only a fraction of the PV system, reducing size and cost of the power converter without affecting system performance.
Jaime W. Zapata; Samir Kouro; Gonzalo Carrasco; Hugues Renaudineau; Thierry Meynard. Analysis of Partial Power DC–DC Converters for Two-Stage Photovoltaic Systems. IEEE Journal of Emerging and Selected Topics in Power Electronics 2018, 7, 591 -603.
AMA StyleJaime W. Zapata, Samir Kouro, Gonzalo Carrasco, Hugues Renaudineau, Thierry Meynard. Analysis of Partial Power DC–DC Converters for Two-Stage Photovoltaic Systems. IEEE Journal of Emerging and Selected Topics in Power Electronics. 2018; 7 (1):591-603.
Chicago/Turabian StyleJaime W. Zapata; Samir Kouro; Gonzalo Carrasco; Hugues Renaudineau; Thierry Meynard. 2018. "Analysis of Partial Power DC–DC Converters for Two-Stage Photovoltaic Systems." IEEE Journal of Emerging and Selected Topics in Power Electronics 7, no. 1: 591-603.
This work presents a partial power converter allowing us to obtain, with a single DC-DC converter, the same feature as the classical interleaved operation of two converters. More precisely, the proposed topology performs similarly as the input-parallel output-series (IPOS) configuration reducing the current ripple at the input of the system and dividing the individual converters power rating, compared to a single converter. The proposed topology consists of a partial DC-DC converter processing only a fraction of the total power, thus allowing high efficiency. Experimental results are provided to validate the proposed converter topology with a Flyback-based 100 W test bench with a transformer turns ratio n1=n2. Experimental results show high performances reducing the input current ripple around 30%, further increasing the conversion efficiency.
Jaime Wladimir Zapata; Samir Kouro; Gonzalo Carrasco; Hugues Renaudineau. Step-Up Partial Power DC-DC Converters for Two-Stage PV Systems with Interleaved Current Performance. Energies 2018, 11, 357 .
AMA StyleJaime Wladimir Zapata, Samir Kouro, Gonzalo Carrasco, Hugues Renaudineau. Step-Up Partial Power DC-DC Converters for Two-Stage PV Systems with Interleaved Current Performance. Energies. 2018; 11 (2):357.
Chicago/Turabian StyleJaime Wladimir Zapata; Samir Kouro; Gonzalo Carrasco; Hugues Renaudineau. 2018. "Step-Up Partial Power DC-DC Converters for Two-Stage PV Systems with Interleaved Current Performance." Energies 11, no. 2: 357.
Tow-stage configurations used in photovoltaic (PV) architectures (microinverter, string inverter or multistring inverter), are commonly used because of the advantages in front of mismatch conditions. In case of a partial shading scenario (produced by cloudy days and dust accumulation), two-stage architectures reach higher efficiencies compared with the traditional central inverter. It is because, the DC-stage allows a wide voltage range in order to perform maximum power point tracking (MPPT). On the other hand, the additional stage increase the component counts and the conversion losses, which leads to a reduced efficiency compared with the single-stage inverters. This work presents a solution for the traditional two-stage configurations, where the partial power conversion (PPC) concept is implemented in the DC-stage. In that way, the DC-DC converter handles a reduced power allowing a volume reduce and increased power density. Moreover, the AC-stage is made using a cascaded H-bridge topology, which improves the power quality and reduces the components size. Simulations are implemented in order to validate the proposed work.
Jaime Zapata; Samir Kouro; Marcelo A. Perez. Partial power converter for a two-stage photovoltaic cascaded string inverter. IECON 2017 - 43rd Annual Conference of the IEEE Industrial Electronics Society 2017, 7831 -7836.
AMA StyleJaime Zapata, Samir Kouro, Marcelo A. Perez. Partial power converter for a two-stage photovoltaic cascaded string inverter. IECON 2017 - 43rd Annual Conference of the IEEE Industrial Electronics Society. 2017; ():7831-7836.
Chicago/Turabian StyleJaime Zapata; Samir Kouro; Marcelo A. Perez. 2017. "Partial power converter for a two-stage photovoltaic cascaded string inverter." IECON 2017 - 43rd Annual Conference of the IEEE Industrial Electronics Society , no. : 7831-7836.
The light-emitting diode (LED) technology is reaching a high penetration in commercial applications oriented to illumination. However, there are some problems associated when the application requires a high output power. The problems are related to the connection of several LED units to reach the voltage and current levels. The voltage-current characteristic of the LEDs is not always the same, specially when a failure occurs. Therefore, when some strings are connected in parallel, the illumination is not uniform if the same voltage is applied to all strings. For that reason, in this paper a multi-channel current balancing driver is proposed. The driver is based on a partial power DC-DC converter architecture. It performs current balancing handling only a portion of the total power delivered by the source, reaching an increased efficiency. Besides, due to the modularity of the architecture, it allows the parallel connection of as many strings as required to use for high power application. Simulations are performed in order to evaluate the converter performance.
Jaime W. Zapata; Thierry Meynard; Samir Kouro. Multi-channel partial power DC-DC converter for current balancing of LED strings. 2017 IEEE 26th International Symposium on Industrial Electronics (ISIE) 2017, 775 -780.
AMA StyleJaime W. Zapata, Thierry Meynard, Samir Kouro. Multi-channel partial power DC-DC converter for current balancing of LED strings. 2017 IEEE 26th International Symposium on Industrial Electronics (ISIE). 2017; ():775-780.
Chicago/Turabian StyleJaime W. Zapata; Thierry Meynard; Samir Kouro. 2017. "Multi-channel partial power DC-DC converter for current balancing of LED strings." 2017 IEEE 26th International Symposium on Industrial Electronics (ISIE) , no. : 775-780.
In photovoltaic (PV) systems, a wide variety of power converter topologies and PV configurations have been developed in order to increase the system efficiency. Traditionally, grid-connected PV systems use one or two conversion stages. The single conversion stage is mainly used for large-scale PV systems working with only a DC-AC converter. Whereas, for small and medium-scale, two conversion stages are used. The advantages working with a DC-stage are mainly the distributed maximum power point tracking (MPPT) algorithm and the elevation capability, but it presents a reduced conversion efficiency compared with the single stage configurations. On the other hand, the single conversion stage presents a reduced overall efficiency produced by partial shading. The proposed work presents a Partial Power DC-DC converter (PPC) which process only a portion of the whole power, reducing the conversion losses. It includes the benefits of two stage configurations so that it performs individual MPPT. Besides, due to the modularity of the architecture, it allows the parallel connection of many strings as required to use in large-scale PV systems. Simulations are performed in order to evaluate the converter performance.
Jaime Zapata; Thierry Meynard; Samir Kouro. Partial power DC-DC converter for large-scale photovoltaic systems. 2016 IEEE 2nd Annual Southern Power Electronics Conference (SPEC) 2017, 1 -6.
AMA StyleJaime Zapata, Thierry Meynard, Samir Kouro. Partial power DC-DC converter for large-scale photovoltaic systems. 2016 IEEE 2nd Annual Southern Power Electronics Conference (SPEC). 2017; ():1-6.
Chicago/Turabian StyleJaime Zapata; Thierry Meynard; Samir Kouro. 2017. "Partial power DC-DC converter for large-scale photovoltaic systems." 2016 IEEE 2nd Annual Southern Power Electronics Conference (SPEC) , no. : 1-6.
In order to increase the conversion efficiency in photovoltaic (PV) systems, different configurations and topologies were developed. Depending on the application, the converters used for grid connection are built using one or two conversion stages. The advantages of the converters with a DC-stage are mainly the distributed maximum power point tracking algorithm per PV string or PV module and, when required for grid connection, the possibility of voltage elevation. However, the conversion efficiency is lower than configurations with a single-stage as the central inverter. Therefore, the proposed work presents a Partial Power DC-DC converter (PPC) which process part of the entire system power, and the remaining power is directly supplied to the output side. A topology is proposed and the details of its operation are explained based on the operating principle. Simulations are performed in order to evaluate the converter performance.
Jaime Zapata; Hugues Renaudineau; Samir Kouro; Marcelo A. Perez; Thierry Meynard. Partial power DC-DC converter for photovoltaic microinverters. IECON 2016 - 42nd Annual Conference of the IEEE Industrial Electronics Society 2016, 6740 -6745.
AMA StyleJaime Zapata, Hugues Renaudineau, Samir Kouro, Marcelo A. Perez, Thierry Meynard. Partial power DC-DC converter for photovoltaic microinverters. IECON 2016 - 42nd Annual Conference of the IEEE Industrial Electronics Society. 2016; ():6740-6745.
Chicago/Turabian StyleJaime Zapata; Hugues Renaudineau; Samir Kouro; Marcelo A. Perez; Thierry Meynard. 2016. "Partial power DC-DC converter for photovoltaic microinverters." IECON 2016 - 42nd Annual Conference of the IEEE Industrial Electronics Society , no. : 6740-6745.
In order to increase the conversion efficiency in photovoltaic (PV) systems, different configurations and topologies were developed. Depending on the application, the converters used for grid connection are built using one or two conversion stages. The advantages of the converters with a DC-stage are mainly the distributed maximum power point tracking algorithm per PV string, a wider range of operation, higher energy yield and, when required for grid connection, the possibility of voltage regulation. However, the conversion efficiency is lower than configurations with a single stage as the central inverter. Therefore, the proposed work presents a Partial Power DC-DC converter (PPC) which process part of the entire system power, and the surplus power is directly supplied to the output side. A topology is proposed and the details of its operation are explained based on the operating principle. Simulations are performed in order to evaluate the converter performance.
Alexander Morrison; Jaime Zapata; Samir Kouro; Marcelo A. Perez; Thierry Meynard; Hugues Renaudineau. Partial power DC-DC converter for photovoltaic two-stage string inverters. 2016 IEEE Energy Conversion Congress and Exposition (ECCE) 2016, 1 -6.
AMA StyleAlexander Morrison, Jaime Zapata, Samir Kouro, Marcelo A. Perez, Thierry Meynard, Hugues Renaudineau. Partial power DC-DC converter for photovoltaic two-stage string inverters. 2016 IEEE Energy Conversion Congress and Exposition (ECCE). 2016; ():1-6.
Chicago/Turabian StyleAlexander Morrison; Jaime Zapata; Samir Kouro; Marcelo A. Perez; Thierry Meynard; Hugues Renaudineau. 2016. "Partial power DC-DC converter for photovoltaic two-stage string inverters." 2016 IEEE Energy Conversion Congress and Exposition (ECCE) , no. : 1-6.
The development of different configurations and topologies implemented in photovoltaic (PV) plants have made possible the increase of efficiency of the system. The traditional configurations of grid-connected PV systems, centralized, string, multi-string and ac-module, have been analyzed and actually most of them are controlled using classic PI control. Furthermore, each of them has different efficiency values due to the inherent associated problems. The large-scale PV plants do not work properly when the modules do not work at the same conditions, for example when some atmospheric and environmental problems are involved, it reduces the reliability of the system. The traditional small-scale PV configurations have a low efficiency due to the dc-boosting stage in order to reach the grid levels. This work presents a grid-connected PV configuration, focused in the improve of the efficiency of the traditional ac-module configuration, a flyback topology for the dc-side and a H-bridge topology for the grid connection will be implemented. Moreover, the proposed control scheme is based on FCS-MPC algorithm.
Jaime W. Zapata; Samir Kouro; Matias Aguirre; Thierry Meynard. Model predictive control of interleaved dc-dc stage for photovoltaic microconverters. IECON 2015 - 41st Annual Conference of the IEEE Industrial Electronics Society 2015, 004311 -004316.
AMA StyleJaime W. Zapata, Samir Kouro, Matias Aguirre, Thierry Meynard. Model predictive control of interleaved dc-dc stage for photovoltaic microconverters. IECON 2015 - 41st Annual Conference of the IEEE Industrial Electronics Society. 2015; ():004311-004316.
Chicago/Turabian StyleJaime W. Zapata; Samir Kouro; Matias Aguirre; Thierry Meynard. 2015. "Model predictive control of interleaved dc-dc stage for photovoltaic microconverters." IECON 2015 - 41st Annual Conference of the IEEE Industrial Electronics Society , no. : 004311-004316.
The continuous increased installation of solar photovoltaic (PV) systems have made possible the interest in their development, oriented to reach a high efficiency system. There are four traditional configurations of grid-connected PV systems depending of the size of the plant,each of them has different efficiency values due to the inherent associated problems. The large-scale PV plants have problems when the modules do not work at the same conditions, for example when some atmospheric and environmental problems are involved, it reduces the reliability of the system. The traditional small-scale PV configurations have a low efficiency due to the dc-boosting stage in order to reach the grid levels. This work presents a grid-connected PV configuration, focused in the improve of the efficiency of the traditional ac-module configuration, a flyback topology for the dc-side and, a H-bridge topology for the grid connection will be implemented.
Jaime W. Zapata; Samir Kouro; Thierry Meynard. Evaluation of output connections of interleaved dc-converter stage for photovoltaic ac-module configurations. 2015 IEEE 13th Brazilian Power Electronics Conference and 1st Southern Power Electronics Conference (COBEP/SPEC) 2015, 1 -6.
AMA StyleJaime W. Zapata, Samir Kouro, Thierry Meynard. Evaluation of output connections of interleaved dc-converter stage for photovoltaic ac-module configurations. 2015 IEEE 13th Brazilian Power Electronics Conference and 1st Southern Power Electronics Conference (COBEP/SPEC). 2015; ():1-6.
Chicago/Turabian StyleJaime W. Zapata; Samir Kouro; Thierry Meynard. 2015. "Evaluation of output connections of interleaved dc-converter stage for photovoltaic ac-module configurations." 2015 IEEE 13th Brazilian Power Electronics Conference and 1st Southern Power Electronics Conference (COBEP/SPEC) , no. : 1-6.
Solar photovoltaic (PV) energy has grown significantly during the last years. However, despite of the increase in installed capacity penetration, this energy source still arises important concerns due to the variability of power production. The short-term effects such as cloud shadowing and supply interruptions, as well as long-term effects such as dust accumulation, seasonal variation and ageing of PV modules can generate variability of power production. Therefore, the analysis of all the variability sources in order to provide a statistically consistent power production data represents an important challenge. This work presents a methodology to analyze data from a PV plant located in Chile by isolating the effect produced by soiling and, with this information a cost based cleaning program is proposed.
Jaime W. Zapata; Marcelo A. Perez; Samir Kouro. Design of a cleaning program for a PV plant based on the analysis of short-term and long-term effects. IECON 2015 - 41st Annual Conference of the IEEE Industrial Electronics Society 2015, 001301 -001306.
AMA StyleJaime W. Zapata, Marcelo A. Perez, Samir Kouro. Design of a cleaning program for a PV plant based on the analysis of short-term and long-term effects. IECON 2015 - 41st Annual Conference of the IEEE Industrial Electronics Society. 2015; ():001301-001306.
Chicago/Turabian StyleJaime W. Zapata; Marcelo A. Perez; Samir Kouro. 2015. "Design of a cleaning program for a PV plant based on the analysis of short-term and long-term effects." IECON 2015 - 41st Annual Conference of the IEEE Industrial Electronics Society , no. : 001301-001306.
Solar photovoltaic (PV) energy has grown significantly over the past few years. However, despite the increase in installed capacity, this energy source still raises important concerns related to the variability of power production. The short-term effects such as cloud shadowing and supply interruptions, as well as long-term effects such as dust accumulation, seasonal variation, and ageing of PV modules, can cause variability of power production. Therefore, the analysis of all the variability sources in order to provide statistically consistent power production data is an important challenge. This study presents a methodology to analyze data from a PV plant in order to have an independent evaluation of the different effects of variability, identifying dust deposition, and proposing a cost-based optimal cleaning program for a PV plant installed in the northern region of Chile.
Jaime W. Zapata; Marcelo A. Perez; Samir Kouro; Anssi Lensu; Anna Suuronen. Design of a Cleaning Program for a PV Plant Based on Analysis of Energy Losses. IEEE Journal of Photovoltaics 2015, 5, 1748 -1756.
AMA StyleJaime W. Zapata, Marcelo A. Perez, Samir Kouro, Anssi Lensu, Anna Suuronen. Design of a Cleaning Program for a PV Plant Based on Analysis of Energy Losses. IEEE Journal of Photovoltaics. 2015; 5 (6):1748-1756.
Chicago/Turabian StyleJaime W. Zapata; Marcelo A. Perez; Samir Kouro; Anssi Lensu; Anna Suuronen. 2015. "Design of a Cleaning Program for a PV Plant Based on Analysis of Energy Losses." IEEE Journal of Photovoltaics 5, no. 6: 1748-1756.
Solar photovoltaic (PV) energy has one of the fastest growth among renewable energies, reaching an installed capacity of 100 GW in year 2012, mainly due by the cost reduction of PV panels. However, one of the main disadvantages of this kind of energy source is their highly variability. The main source of variability is, of course, the day/night cycle. Nevertheless, short-term effects such as cloud shadowing and supply interruptions and long-term effects such as dust accumulation, seasonal variation and ageing of panels will also appear as sources of variability. The combined effect of all these variability sources makes the analysis of the power production data very complex. The reliability and accuracy of this data analysis could becomes significant because it is required to expand the PV plant size, to design a new one, to incorporate energy storage for power smoothing or to economically evaluate the PV system. This work presents a methodology to obtain statistically consistent data from a PV plant, in order to evaluate all the mentioned effects separately. The method is based on the correlation of PV power production data with an ideal value of solar power obtained from geographical and astronomical data. The proposed methodology is applied to data obtained from a PV plant located in northern Chile.
Marcelo A. Perez; Jaime Zapata. Analysis of short-term and long-term characteristics of PV power production. 2014 IEEE 23rd International Symposium on Industrial Electronics (ISIE) 2014, 2478 -2483.
AMA StyleMarcelo A. Perez, Jaime Zapata. Analysis of short-term and long-term characteristics of PV power production. 2014 IEEE 23rd International Symposium on Industrial Electronics (ISIE). 2014; ():2478-2483.
Chicago/Turabian StyleMarcelo A. Perez; Jaime Zapata. 2014. "Analysis of short-term and long-term characteristics of PV power production." 2014 IEEE 23rd International Symposium on Industrial Electronics (ISIE) , no. : 2478-2483.