Vicente Salas | Universidad Carlos III de Madrid (original) (raw)

Papers by Vicente Salas

En este artículo se han analizado, a partir de las hojas características de los fabricantes, los ... more En este artículo se han analizado, a partir de las hojas características de los fabricantes, los in- versores fotovoltaicos híbridos aislados, los cuales pueden combinar cuatro posibles fuentes de energía: campo fotovoltaico, banco de baterías, grupo de respaldo y red eléctrica. De esta forma, puede resultar una solución ideal cuando se busque una solución alternativa a la red pública eléc- trica o como un sistema de alimentación ininterrumpida, en áreas de suministro inestable.

This work presents in a simple and practical way how read from a computer the energy values recor... more This work presents in a simple and practical way how read from a computer the energy values recorded by standard energy meters installed in PV grid connected systems in order to be monitored local or remotely. This communication can be easily implemented as a software program itself or integrated as a part in any other monitoring software. Remote energy metering for PV grid connected installations is used, exclusively in most of the installations, by the electrical company for remote energy metering and automatic billing. Energy meters communications from any manufacturer must fulfill the IEC 870-5-102 standard, mandatory in Spain, and complemented by the Electrical Grid Company, REE, regulation. For remote energy metering the user must install a GSM modem and supply to the electrical companies the phone number and counters addresses and passwords in order to perform automatic energy telereadings using software programs. Local energy metering is easily implementable trough energy meters RS485 network and the communication protocol explained in this work.

A total of 14 string PV inverters for low voltage grid-connected PV systems has been selected fro... more A total of 14 string PV inverters for low voltage grid-connected PV systems has been selected from the actual market state of the art and tested in the CIEMAT PV Laboratory. The inverters electrical conversion efficiency, current total harmonic distortion and power factor are presented. The European Efficiency concept is redefined for sun tracking and fixed systems in function of the local irradiance distributions. The maximum power point tracking of the PV array is evaluated from an own developed procedure based on the measurements using a real PV array in clear days and days with clouds. The DC current injection into the electrical grid is investigated and results for inverters having LF, HF transformers or transformerless inverters are analysed. Different standards and regulations applicable to PV grid connected inverters are also presented.

The aim of this article is to describe how closely PV grid-connected inverters operate at the act... more The aim of this article is to describe how closely PV grid-connected inverters operate at the actual maximum power point. To carry this study out six 50 Hz single-phase inverters were selected from European market. Each one of them was put into an outdoor grid-connected system installed in Leganes (Madrid) Spain (by using flat and concentrating PV modules). Different electrical signals with respect to irradiance, PV module temperature and local time were measured. DC voltage and maximum power point tracking were analysed.

This presentation will discuss an analysis of DC and AC coupling implemented in PV stand-alone hy... more This presentation will discuss an analysis of DC and AC coupling implemented in PV stand-alone hybrid systems with AC loads. In terms of the energy efficiency of the elements involved, it will be shown that the power profile determines the total system efficiency. In recent years, the AC coupling has gained attention in relation to traditional DC-coupled Systems - even more so in light of technical improvements implemented in bidirectional inverters. However, this presentation contends that AC coupling is not always the best solution for every off-grid hybrid configuration, depending the load profile. In order to evaluate both implementations, two systems were analyzed in regards to the common elements - the PV generator and battery bank. Different situations will be examined in terms of energy used directly to the AC load or stored.

The International Energy Agency – Photovoltaic Power System Programme (IEA PVPS)’s Task 1 is resp... more The International Energy Agency – Photovoltaic Power System Programme (IEA PVPS)’s Task 1 is responsible for strategy and outreach within the IEA PVPS program: this includes market and industry analysis. A key deliverable of Task 1 is the annual Trends in photovoltaic applications publication. This report gives information on trends in PV power applications in the PVPS member and non-member countries and is largely based on the information provided in the National Survey Reports that are produced by 24 IEA PVPS countries. The surveys include information on national market developments, public budgets, the industry value chain, prices, economic benefits, new initiatives, electricity utility interests, standards and codes and Research, Development & Demonstration (RD&D) plus technology overviews. This paper will present the latest survey results for the calendar year 2013 concerning PV markets and policies, as well as other key issues. An increasing number of national markets experien...

The object of this paper is the analysis of European efficiency. It consists of a formula introdu... more The object of this paper is the analysis of European efficiency. It consists of a formula introduced in 1991 whose coefficients are, at the moment, constant and independent of latitude. The weighting European Efficiency factors refer to the irradiance distribution in north-western Germany at that time. These factors are therefore not necessarily representative for all parts of Europe, especially not for southern Europe. However, today they provide a well established value for a quick comparison of conversion efficiency of inverters. In a similar way, this paper will discuss how those coefficients vary in function of latitude and the tracking type.

Conference Record of the IEEE Photovoltaic Specialists Conference

This paper discusses and analyzes the degradation of five PV modules of different actual technolo... more This paper discusses and analyzes the degradation of five PV modules of different actual technologies with long-time outdoors exposure. The degradation losses are analyzed by means of the following parameters: short circuit current, open circuit voltage and power. At the same time, this paper compares the degradation of five different technology modules, measured in the same place with the same equipment that captures the parameters measured. It explains the degradation of the modules over time to take into account all the calculations for decision making when designing a photovoltaic installation. Each one of them was set outdoor at the Universidad Carlos III de Madrid, Leganes (Madrid), Spain.

2011 37th IEEE Photovoltaic Specialists Conference, 2011

The aim of this article is to describe how closely the low voltage small grid-connected PV invert... more The aim of this article is to describe how closely the low voltage small grid-connected PV inverters of 100 kW operate at the actual maximum power point. To carry this study out, three, 50 Hz three-phase inverters, from different manufacturers, were selected from the European market. Each one of them was put into an outdoor gridconnected system installed in different locations in the South of Spain (Seville and Murcia). PV voltage, current and power generation with respect to irradiance, cells temperature and local time were measured under different meteorological conditions. The maximum power point voltage and the ratio between PV current and irradiance were analysed.

2009 34th IEEE Photovoltaic Specialists Conference (PVSC), 2009

The aim of this article is to describe how closely PV grid-connected inverters operate at the act... more The aim of this article is to describe how closely PV grid-connected inverters operate at the actual maximum power point. To carry this study out six 50 Hz single-phase inverters were selected from European market, around of 5 kW. Each one of them was put into an outdoor gridconnected system installed in Leganes (Madrid), Spain. Different electrical signals with respect to irradiance, PV module temperature and local time were measured. DC voltage and maximum power point tracking were analysed.

2011 37th IEEE Photovoltaic Specialists Conference, 2011

The objective of this article is to discuss the new photovoltaic policy recently approval by the ... more The objective of this article is to discuss the new photovoltaic policy recently approval by the Spanish government. If the Spanish market has been seriously damaged during 2010 precisely by the Spanish policy started in 2009, with the new Royal Decrees and Law published in the end of 2010 will cause serious problems in the PV Spanish market not only in 2011 even in the future.

IEEE 36th Conference on Power Electronics Specialists, 2005., 2005

This paper proposes the use of a single-stage PFC converter to feed those cost-effective applicat... more This paper proposes the use of a single-stage PFC converter to feed those cost-effective applications which must comply with Class D limits of IEC 61000-3-2 in the range of 500W. The circuit operation, design guidelines of the converter have been presented for both European and universal line-voltage range. Finally, experimental results are provided in order to check the performance of the proposed converter and its design. 0-7803-9033

ISIE'2000. Proceedings of the 2000 IEEE International Symposium on Industrial Electronics (Cat. No.00TH8543), 2000

This paper presents the results of an achieved designed method for an optimum combination of a hy... more This paper presents the results of an achieved designed method for an optimum combination of a hybrid power system (HPS) based on photovoltaic, battery and liquefied petroleum gas genset (PV/BAT/LPG) in remote telecommunications equipment. From the various forms of feeding such equipment independently to the public grid, a solution is proposed that combines two redundant sources (one of them renewable energy) procured to widen the availability with respect to PV and LPG stand-alone systems. Then, this hybrid system can guarantee the certainty of meeting load demands at all times at reasonable cost, for certain latitudes and escapes of the total dependency of the resources of the hydrocarbons and the economic viability of some other energetic alternatives. As an example for Braunschweig (Germany) the best combination reduces by 55% the total cost compared to PV stand-alone. In this way, hybrid power systems are oriented to be deployed in remote areas, outside of the central office, where utility lines are uneconomical to install due to terrain or environmental concerns

2010 35th IEEE Photovoltaic Specialists Conference, 2010

The aim of this article is to present the design and implementation of a new tracker. A compariso... more The aim of this article is to present the design and implementation of a new tracker. A comparison will also be conducted between a new PV tracking grid-connected system and a fixed PV grid-connected system, with the same power. Those systems were installed at the Universidad Carlos III de Madrid, Leganes (Madrid), in Spain. To do this, it was necessary to obtain and compare the actual power output of very inverter. The same PV generator and grid-connected inverters were installed in every system type. The only difference between installations was the type of tracking system used.

IEEE 2002 28th Annual Conference of the Industrial Electronics Society. IECON 02, 2002

Absfracf -This paper presents the study of the control strategies enclosed in photovoltaic charge... more Absfracf -This paper presents the study of the control strategies enclosed in photovoltaic charge control, including Maximum Power Point Trackers (MPPT's). It was simulated and evaluated using simulating tool Sirnulink@. It is supposed to he integrated on a Photovoltaic Stand-alone Systems where it is very important to maximize the efficiency of its power source: the array of photovoltaics panels

Proceedings of the IEEE International Symposium on Industrial Electronics ISIE-02, 2002

This paper presents the study of conditioning power systems applied to stand-alone systems, inclu... more This paper presents the study of conditioning power systems applied to stand-alone systems, including Maximum Power Point Trackers (MPPT's), simulated and evaluated using simulating tool Simulink'. It is supposed to be integrated on a Photovoltaic Stand-alone Systems. Since space and weigh are very limited in the environment of a moving vehicle it is very important to maximize the efficiency of its power source: the array of photovoltaics panels.

INTELEC. Twenty-Second International Telecommunications Energy Conference (Cat. No.00CH37131), 2000

Gas genset (PV/BAT/LPG) in remote telecommunications equipment of low power. From the various for... more Gas genset (PV/BAT/LPG) in remote telecommunications equipment of low power. From the various forms of supplying such equipments not connected to the public grid, it is proposed a solution that combines three sources (one of them renewable energy), providing redundancy. It is procured to widen the availability. Then, this HPS system guarantees a continuos energy supply at reasonable cost, positive ecological effects and escapes of the total dependency of the resources of the hydrocarbons and the economic viability of some other energetic alternatives.

En este artículo se han analizado, a partir de las hojas características de los fabricantes, los ... more En este artículo se han analizado, a partir de las hojas características de los fabricantes, los in- versores fotovoltaicos híbridos aislados, los cuales pueden combinar cuatro posibles fuentes de energía: campo fotovoltaico, banco de baterías, grupo de respaldo y red eléctrica. De esta forma, puede resultar una solución ideal cuando se busque una solución alternativa a la red pública eléc- trica o como un sistema de alimentación ininterrumpida, en áreas de suministro inestable.

This work presents in a simple and practical way how read from a computer the energy values recor... more This work presents in a simple and practical way how read from a computer the energy values recorded by standard energy meters installed in PV grid connected systems in order to be monitored local or remotely. This communication can be easily implemented as a software program itself or integrated as a part in any other monitoring software. Remote energy metering for PV grid connected installations is used, exclusively in most of the installations, by the electrical company for remote energy metering and automatic billing. Energy meters communications from any manufacturer must fulfill the IEC 870-5-102 standard, mandatory in Spain, and complemented by the Electrical Grid Company, REE, regulation. For remote energy metering the user must install a GSM modem and supply to the electrical companies the phone number and counters addresses and passwords in order to perform automatic energy telereadings using software programs. Local energy metering is easily implementable trough energy meters RS485 network and the communication protocol explained in this work.

A total of 14 string PV inverters for low voltage grid-connected PV systems has been selected fro... more A total of 14 string PV inverters for low voltage grid-connected PV systems has been selected from the actual market state of the art and tested in the CIEMAT PV Laboratory. The inverters electrical conversion efficiency, current total harmonic distortion and power factor are presented. The European Efficiency concept is redefined for sun tracking and fixed systems in function of the local irradiance distributions. The maximum power point tracking of the PV array is evaluated from an own developed procedure based on the measurements using a real PV array in clear days and days with clouds. The DC current injection into the electrical grid is investigated and results for inverters having LF, HF transformers or transformerless inverters are analysed. Different standards and regulations applicable to PV grid connected inverters are also presented.

The aim of this article is to describe how closely PV grid-connected inverters operate at the act... more The aim of this article is to describe how closely PV grid-connected inverters operate at the actual maximum power point. To carry this study out six 50 Hz single-phase inverters were selected from European market. Each one of them was put into an outdoor grid-connected system installed in Leganes (Madrid) Spain (by using flat and concentrating PV modules). Different electrical signals with respect to irradiance, PV module temperature and local time were measured. DC voltage and maximum power point tracking were analysed.

This presentation will discuss an analysis of DC and AC coupling implemented in PV stand-alone hy... more This presentation will discuss an analysis of DC and AC coupling implemented in PV stand-alone hybrid systems with AC loads. In terms of the energy efficiency of the elements involved, it will be shown that the power profile determines the total system efficiency. In recent years, the AC coupling has gained attention in relation to traditional DC-coupled Systems - even more so in light of technical improvements implemented in bidirectional inverters. However, this presentation contends that AC coupling is not always the best solution for every off-grid hybrid configuration, depending the load profile. In order to evaluate both implementations, two systems were analyzed in regards to the common elements - the PV generator and battery bank. Different situations will be examined in terms of energy used directly to the AC load or stored.

The International Energy Agency – Photovoltaic Power System Programme (IEA PVPS)’s Task 1 is resp... more The International Energy Agency – Photovoltaic Power System Programme (IEA PVPS)’s Task 1 is responsible for strategy and outreach within the IEA PVPS program: this includes market and industry analysis. A key deliverable of Task 1 is the annual Trends in photovoltaic applications publication. This report gives information on trends in PV power applications in the PVPS member and non-member countries and is largely based on the information provided in the National Survey Reports that are produced by 24 IEA PVPS countries. The surveys include information on national market developments, public budgets, the industry value chain, prices, economic benefits, new initiatives, electricity utility interests, standards and codes and Research, Development & Demonstration (RD&D) plus technology overviews. This paper will present the latest survey results for the calendar year 2013 concerning PV markets and policies, as well as other key issues. An increasing number of national markets experien...

The object of this paper is the analysis of European efficiency. It consists of a formula introdu... more The object of this paper is the analysis of European efficiency. It consists of a formula introduced in 1991 whose coefficients are, at the moment, constant and independent of latitude. The weighting European Efficiency factors refer to the irradiance distribution in north-western Germany at that time. These factors are therefore not necessarily representative for all parts of Europe, especially not for southern Europe. However, today they provide a well established value for a quick comparison of conversion efficiency of inverters. In a similar way, this paper will discuss how those coefficients vary in function of latitude and the tracking type.

Conference Record of the IEEE Photovoltaic Specialists Conference

This paper discusses and analyzes the degradation of five PV modules of different actual technolo... more This paper discusses and analyzes the degradation of five PV modules of different actual technologies with long-time outdoors exposure. The degradation losses are analyzed by means of the following parameters: short circuit current, open circuit voltage and power. At the same time, this paper compares the degradation of five different technology modules, measured in the same place with the same equipment that captures the parameters measured. It explains the degradation of the modules over time to take into account all the calculations for decision making when designing a photovoltaic installation. Each one of them was set outdoor at the Universidad Carlos III de Madrid, Leganes (Madrid), Spain.

2011 37th IEEE Photovoltaic Specialists Conference, 2011

The aim of this article is to describe how closely the low voltage small grid-connected PV invert... more The aim of this article is to describe how closely the low voltage small grid-connected PV inverters of 100 kW operate at the actual maximum power point. To carry this study out, three, 50 Hz three-phase inverters, from different manufacturers, were selected from the European market. Each one of them was put into an outdoor gridconnected system installed in different locations in the South of Spain (Seville and Murcia). PV voltage, current and power generation with respect to irradiance, cells temperature and local time were measured under different meteorological conditions. The maximum power point voltage and the ratio between PV current and irradiance were analysed.

2009 34th IEEE Photovoltaic Specialists Conference (PVSC), 2009

The aim of this article is to describe how closely PV grid-connected inverters operate at the act... more The aim of this article is to describe how closely PV grid-connected inverters operate at the actual maximum power point. To carry this study out six 50 Hz single-phase inverters were selected from European market, around of 5 kW. Each one of them was put into an outdoor gridconnected system installed in Leganes (Madrid), Spain. Different electrical signals with respect to irradiance, PV module temperature and local time were measured. DC voltage and maximum power point tracking were analysed.

2011 37th IEEE Photovoltaic Specialists Conference, 2011

The objective of this article is to discuss the new photovoltaic policy recently approval by the ... more The objective of this article is to discuss the new photovoltaic policy recently approval by the Spanish government. If the Spanish market has been seriously damaged during 2010 precisely by the Spanish policy started in 2009, with the new Royal Decrees and Law published in the end of 2010 will cause serious problems in the PV Spanish market not only in 2011 even in the future.

IEEE 36th Conference on Power Electronics Specialists, 2005., 2005

This paper proposes the use of a single-stage PFC converter to feed those cost-effective applicat... more This paper proposes the use of a single-stage PFC converter to feed those cost-effective applications which must comply with Class D limits of IEC 61000-3-2 in the range of 500W. The circuit operation, design guidelines of the converter have been presented for both European and universal line-voltage range. Finally, experimental results are provided in order to check the performance of the proposed converter and its design. 0-7803-9033

ISIE'2000. Proceedings of the 2000 IEEE International Symposium on Industrial Electronics (Cat. No.00TH8543), 2000

This paper presents the results of an achieved designed method for an optimum combination of a hy... more This paper presents the results of an achieved designed method for an optimum combination of a hybrid power system (HPS) based on photovoltaic, battery and liquefied petroleum gas genset (PV/BAT/LPG) in remote telecommunications equipment. From the various forms of feeding such equipment independently to the public grid, a solution is proposed that combines two redundant sources (one of them renewable energy) procured to widen the availability with respect to PV and LPG stand-alone systems. Then, this hybrid system can guarantee the certainty of meeting load demands at all times at reasonable cost, for certain latitudes and escapes of the total dependency of the resources of the hydrocarbons and the economic viability of some other energetic alternatives. As an example for Braunschweig (Germany) the best combination reduces by 55% the total cost compared to PV stand-alone. In this way, hybrid power systems are oriented to be deployed in remote areas, outside of the central office, where utility lines are uneconomical to install due to terrain or environmental concerns

2010 35th IEEE Photovoltaic Specialists Conference, 2010

The aim of this article is to present the design and implementation of a new tracker. A compariso... more The aim of this article is to present the design and implementation of a new tracker. A comparison will also be conducted between a new PV tracking grid-connected system and a fixed PV grid-connected system, with the same power. Those systems were installed at the Universidad Carlos III de Madrid, Leganes (Madrid), in Spain. To do this, it was necessary to obtain and compare the actual power output of very inverter. The same PV generator and grid-connected inverters were installed in every system type. The only difference between installations was the type of tracking system used.

IEEE 2002 28th Annual Conference of the Industrial Electronics Society. IECON 02, 2002

Absfracf -This paper presents the study of the control strategies enclosed in photovoltaic charge... more Absfracf -This paper presents the study of the control strategies enclosed in photovoltaic charge control, including Maximum Power Point Trackers (MPPT's). It was simulated and evaluated using simulating tool Sirnulink@. It is supposed to he integrated on a Photovoltaic Stand-alone Systems where it is very important to maximize the efficiency of its power source: the array of photovoltaics panels

Proceedings of the IEEE International Symposium on Industrial Electronics ISIE-02, 2002

This paper presents the study of conditioning power systems applied to stand-alone systems, inclu... more This paper presents the study of conditioning power systems applied to stand-alone systems, including Maximum Power Point Trackers (MPPT's), simulated and evaluated using simulating tool Simulink'. It is supposed to be integrated on a Photovoltaic Stand-alone Systems. Since space and weigh are very limited in the environment of a moving vehicle it is very important to maximize the efficiency of its power source: the array of photovoltaics panels.

INTELEC. Twenty-Second International Telecommunications Energy Conference (Cat. No.00CH37131), 2000

Gas genset (PV/BAT/LPG) in remote telecommunications equipment of low power. From the various for... more Gas genset (PV/BAT/LPG) in remote telecommunications equipment of low power. From the various forms of supplying such equipments not connected to the public grid, it is proposed a solution that combines three sources (one of them renewable energy), providing redundancy. It is procured to widen the availability. Then, this HPS system guarantees a continuos energy supply at reasonable cost, positive ecological effects and escapes of the total dependency of the resources of the hydrocarbons and the economic viability of some other energetic alternatives.