Pub Date : 2019-09-01DOI: 10.1109/ESPC.2019.8932004
V. Giuliani, S. Remy
Nowadays, space market considers the development of Small Satellite as a key factor for LEO missions evolution. One of the main characteristics of these missions is the combination between performance achievable and low mission costs. It is then extremely important to reduce mission expenses and one aspect of paramount importance, when lowering development costs, is the use of technologies not specifically developed for the space environment. In this context, S.A.B. Aerospace started a project for the qualification of a modular battery pack equipped with elementary cells based on a Lithium-Cobalt (LiCoO2) electrochemical system, which are not specifically born for space applications. The fundamental element of the battery pack is called “Module”: it integrates 8 Li-Ion cells connected in series and it is equipped with a PCB for passive voltage balancing. The modular concept allows the maximum versatility, satisfying power and energy demands for many different spacecrafts, depending on the number of integrated modules. This project is the follow up of the initiative undertaken to develop a battery pack for LARES (Laser Relativity Satellite) mission within the VEGA Launcher maiden Flight. Being the lifetime for the payload separation way shorter than in orbit servicing, a delta development is needed to show the compliance to Satellites missions. Thus, an innovative and accurate method to predict the available EoL (End of Life) capacity has been defined to show the suitability to the specific applications. Such method is based on the correlation between data collected from an Accelerated Lifecycle Test and mathematical method solutions. In this way, it is possible to set-up a test performing about 20% of duty cycles carried out from the battery during its overall lifetime, using maximum allowable charge/discharge rate to accelerate the capacity fading rather than a thermal chamber. After Accelerated Lifecycle test execution a Nominal Lifecycle test will be carried out, in order to investigate capacity fading effects on the battery with respect to the real power mission profile.
{"title":"Qualification of a modular Li-ion battery pack for LEO Satellites based on cells not specifically designed for space applications","authors":"V. Giuliani, S. Remy","doi":"10.1109/ESPC.2019.8932004","DOIUrl":"https://doi.org/10.1109/ESPC.2019.8932004","url":null,"abstract":"Nowadays, space market considers the development of Small Satellite as a key factor for LEO missions evolution. One of the main characteristics of these missions is the combination between performance achievable and low mission costs. It is then extremely important to reduce mission expenses and one aspect of paramount importance, when lowering development costs, is the use of technologies not specifically developed for the space environment. In this context, S.A.B. Aerospace started a project for the qualification of a modular battery pack equipped with elementary cells based on a Lithium-Cobalt (LiCoO2) electrochemical system, which are not specifically born for space applications. The fundamental element of the battery pack is called “Module”: it integrates 8 Li-Ion cells connected in series and it is equipped with a PCB for passive voltage balancing. The modular concept allows the maximum versatility, satisfying power and energy demands for many different spacecrafts, depending on the number of integrated modules. This project is the follow up of the initiative undertaken to develop a battery pack for LARES (Laser Relativity Satellite) mission within the VEGA Launcher maiden Flight. Being the lifetime for the payload separation way shorter than in orbit servicing, a delta development is needed to show the compliance to Satellites missions. Thus, an innovative and accurate method to predict the available EoL (End of Life) capacity has been defined to show the suitability to the specific applications. Such method is based on the correlation between data collected from an Accelerated Lifecycle Test and mathematical method solutions. In this way, it is possible to set-up a test performing about 20% of duty cycles carried out from the battery during its overall lifetime, using maximum allowable charge/discharge rate to accelerate the capacity fading rather than a thermal chamber. After Accelerated Lifecycle test execution a Nominal Lifecycle test will be carried out, in order to investigate capacity fading effects on the battery with respect to the real power mission profile.","PeriodicalId":6734,"journal":{"name":"2019 European Space Power Conference (ESPC)","volume":"1 1","pages":"1-9"},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76123299","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-09-01DOI: 10.1109/ESPC.2019.8932021
Silvio Baccari, F. Vasca, Elisa Mostacciuolo, L. Iannelli, Salvatore Sagnelli, Raffaele Luisi, V. Stanzione
A model-based characterization technique for lithium-ion batteries adopted in small satellites is proposed. The architecture of a hardware/software platform designed for the experimental analysis is described. Data obtained with suitable testing campaigns are exploited for the identification of the parameters of the battery model through the minimization of a cost function. In particular, the battery model represents either charging and discharging phases, with specific attention to the scenarios typical of electrical power systems in small satellites. Experimental and numerical results show the effectiveness of the proposed solution in terms of accuracy of the identified model.
{"title":"A characterization system for LEO satellites batteries","authors":"Silvio Baccari, F. Vasca, Elisa Mostacciuolo, L. Iannelli, Salvatore Sagnelli, Raffaele Luisi, V. Stanzione","doi":"10.1109/ESPC.2019.8932021","DOIUrl":"https://doi.org/10.1109/ESPC.2019.8932021","url":null,"abstract":"A model-based characterization technique for lithium-ion batteries adopted in small satellites is proposed. The architecture of a hardware/software platform designed for the experimental analysis is described. Data obtained with suitable testing campaigns are exploited for the identification of the parameters of the battery model through the minimization of a cost function. In particular, the battery model represents either charging and discharging phases, with specific attention to the scenarios typical of electrical power systems in small satellites. Experimental and numerical results show the effectiveness of the proposed solution in terms of accuracy of the identified model.","PeriodicalId":6734,"journal":{"name":"2019 European Space Power Conference (ESPC)","volume":"10 38 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81703943","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The Power Processing Unit (PPU) constitutes one of the most challenging parts, from both technical and business point of view, of an Electric Propulsion System (EPS). It is the module of the EPS that contains the electrical circuits responsible for providing power and control to all subsystems with varying demands and in the most efficient way, while its cost is indicatively about 50% of the total cost of an EPS. Space industries are strongly focusing on low cost PPUs while trying to present small in size and weight units with high efficiency and high reliability. In this direction, the main objective of this paper is to illustrate a feasibility study on the budget optimizations that can be achieved, in terms of power, cost, mass and size, on a space qualified low power PPU (<300W) by applying on the one hand COTS (Commercial Off-The-Self) components and on the other hand eGaN (enhancement mode Gallium Nitride) FETs as switching elements taking advantage of the improvements they may offer in the electrical and physical characteristics, retaining though the functionality and the reliability of the whole PPU. As first step, the space environment of a potential LEO mission has been clearly defined taking into account the business strategy, the potential customers and the latest trends in space market. The feasibility study results of the implementation of COTS and eGaN FETs are very promising, demonstrating essential improvements in all budget parameters of the PPU, without affecting its performance. The realization of COTS components and eGaN FETs on a synchronous Buck DC/DC converter is currently being developed in order to verify the conclusions of the study. The outcome of this activity can become the driving step forward in order to integrate the utilization of COTS and eGaN FETs also in other DC/DC converters of a PPU and develop lower in cost, size and mass and more efficient PPUs in the future.
{"title":"Feasibility Study of Low Power PPU with COTS Components and eGaN FETs","authors":"Alexandros Manoudis, Spiridon Savvas, Pavlos Ramnalis","doi":"10.1109/ESPC.2019.8931984","DOIUrl":"https://doi.org/10.1109/ESPC.2019.8931984","url":null,"abstract":"The Power Processing Unit (PPU) constitutes one of the most challenging parts, from both technical and business point of view, of an Electric Propulsion System (EPS). It is the module of the EPS that contains the electrical circuits responsible for providing power and control to all subsystems with varying demands and in the most efficient way, while its cost is indicatively about 50% of the total cost of an EPS. Space industries are strongly focusing on low cost PPUs while trying to present small in size and weight units with high efficiency and high reliability. In this direction, the main objective of this paper is to illustrate a feasibility study on the budget optimizations that can be achieved, in terms of power, cost, mass and size, on a space qualified low power PPU (<300W) by applying on the one hand COTS (Commercial Off-The-Self) components and on the other hand eGaN (enhancement mode Gallium Nitride) FETs as switching elements taking advantage of the improvements they may offer in the electrical and physical characteristics, retaining though the functionality and the reliability of the whole PPU. As first step, the space environment of a potential LEO mission has been clearly defined taking into account the business strategy, the potential customers and the latest trends in space market. The feasibility study results of the implementation of COTS and eGaN FETs are very promising, demonstrating essential improvements in all budget parameters of the PPU, without affecting its performance. The realization of COTS components and eGaN FETs on a synchronous Buck DC/DC converter is currently being developed in order to verify the conclusions of the study. The outcome of this activity can become the driving step forward in order to integrate the utilization of COTS and eGaN FETs also in other DC/DC converters of a PPU and develop lower in cost, size and mass and more efficient PPUs in the future.","PeriodicalId":6734,"journal":{"name":"2019 European Space Power Conference (ESPC)","volume":"114 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90738926","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-09-01DOI: 10.1109/ESPC.2019.8932012
C. Delepaut, H. Carbonnier
Conductance control within SMPS (Switch Mode Power Supply) for space power systems is typically implemented relying on ACC (Average Current Control). Such technique is driven by a comparison between the electrical current and a sawtooth signal being either asymmetrical or symmetrical. An in-depth analysis of the associated dynamics has been published for the asymmetrical sawtooth case only. The present paper consists in the dynamic analysis of ACC using symmetrical sawtooth, resulting in a Laplace transform block diagram properly modelling the limited switching frequency effect. The bandwidth and phase margin of that closed-loop control technique are in particular investigated, highlighting that a symmetrical sawtooth allows to reach a bandwidth twice the one achievable with an asymmetrical sawtooth at given phase margin performance. In the same way that ACC with asymmetrical sawtooth is known to extend to classical PCC (Peak Current Control), the paper also shows that ACC with symmetrical sawtooth extends to an innovative PVCC (Peak and Valley Current Control) technique, using double compensation ramp, which increases the conductance control bandwidth capability to beyond half the switching frequency. Finally, time domain simulations are reported that prove to be consistent with the frequency domain theoretical predictions. Practical measurements have been performed on a breadboard as well and are reported in a separate paper.
{"title":"Average Current Control with Symmetrical Sawtooth or Peak and Valley Current Control","authors":"C. Delepaut, H. Carbonnier","doi":"10.1109/ESPC.2019.8932012","DOIUrl":"https://doi.org/10.1109/ESPC.2019.8932012","url":null,"abstract":"Conductance control within SMPS (Switch Mode Power Supply) for space power systems is typically implemented relying on ACC (Average Current Control). Such technique is driven by a comparison between the electrical current and a sawtooth signal being either asymmetrical or symmetrical. An in-depth analysis of the associated dynamics has been published for the asymmetrical sawtooth case only. The present paper consists in the dynamic analysis of ACC using symmetrical sawtooth, resulting in a Laplace transform block diagram properly modelling the limited switching frequency effect. The bandwidth and phase margin of that closed-loop control technique are in particular investigated, highlighting that a symmetrical sawtooth allows to reach a bandwidth twice the one achievable with an asymmetrical sawtooth at given phase margin performance. In the same way that ACC with asymmetrical sawtooth is known to extend to classical PCC (Peak Current Control), the paper also shows that ACC with symmetrical sawtooth extends to an innovative PVCC (Peak and Valley Current Control) technique, using double compensation ramp, which increases the conductance control bandwidth capability to beyond half the switching frequency. Finally, time domain simulations are reported that prove to be consistent with the frequency domain theoretical predictions. Practical measurements have been performed on a breadboard as well and are reported in a separate paper.","PeriodicalId":6734,"journal":{"name":"2019 European Space Power Conference (ESPC)","volume":"6 9","pages":"1-8"},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91513831","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-09-01DOI: 10.1109/ESPC.2019.8931983
Sungwoo Park, Emma Prestigiacomo, Kyudong Kim, Yungsu Youn, Remy Stéphane
Currently, 3 Korean LEO satellites with various payloads finished their mission life successfully, and all of them have had their life extended for at least 2 years. These 3 satellites are flying with Saft Lithium-Ion batteries, made of Saft high capacity cells, and equipped with ISIS electronics. Life extension was based on spacecraft health status, including battery performances check. The article aims at sharing in-orbit data showing batteries key data such as Depth of Discharge, and performances margins vs designed lives.
{"title":"Extended Leo Missions on Kompsat Series","authors":"Sungwoo Park, Emma Prestigiacomo, Kyudong Kim, Yungsu Youn, Remy Stéphane","doi":"10.1109/ESPC.2019.8931983","DOIUrl":"https://doi.org/10.1109/ESPC.2019.8931983","url":null,"abstract":"Currently, 3 Korean LEO satellites with various payloads finished their mission life successfully, and all of them have had their life extended for at least 2 years. These 3 satellites are flying with Saft Lithium-Ion batteries, made of Saft high capacity cells, and equipped with ISIS electronics. Life extension was based on spacecraft health status, including battery performances check. The article aims at sharing in-orbit data showing batteries key data such as Depth of Discharge, and performances margins vs designed lives.","PeriodicalId":6734,"journal":{"name":"2019 European Space Power Conference (ESPC)","volume":"50 6 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88512458","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-09-01DOI: 10.1109/ESPC.2019.8931996
M. Notarianni, B. Messant, P. Maynadier
To cope with space environment, radiation-hardened MOSFET switches are specifically designed in large dice (limiting their performance such as high parasitic capacitors compared to the ones designed for terrestrial application) and are packaged hermetically (SMDxx, TO25x,…). This leads to a high cost and large footprint, especially for DC/DC supplying high speed processors which require very low voltages and high currents (and consequently a lot of switches). Some GaN HFET designed for terrestrial applications have shown both good radiation robustness, small footprint and good intrinsic parameters (low Rdson and low parasitic capacitors). R&T activities have been done in cooperation with CNES (French Space Agency) to introduce GaN HFET, to put in place the screening process and to highlight the operating margins for space application. As the GaN HFET are massively produced for terrestrial applications, their intrinsic cost makes them attractive, even when space grade qualification has to be done (encapsulation in a hermetic package, screening, testing, burn-in …). Based on this work, Thales Alenia Space has developed and qualified a new generation of DC/DC converter for digital core using GaN HFET and is compared to a radiation hardened MOSFET solution.
{"title":"Using GaN HFET to replace MOSFET in DC/DC for space applications","authors":"M. Notarianni, B. Messant, P. Maynadier","doi":"10.1109/ESPC.2019.8931996","DOIUrl":"https://doi.org/10.1109/ESPC.2019.8931996","url":null,"abstract":"To cope with space environment, radiation-hardened MOSFET switches are specifically designed in large dice (limiting their performance such as high parasitic capacitors compared to the ones designed for terrestrial application) and are packaged hermetically (SMDxx, TO25x,…). This leads to a high cost and large footprint, especially for DC/DC supplying high speed processors which require very low voltages and high currents (and consequently a lot of switches). Some GaN HFET designed for terrestrial applications have shown both good radiation robustness, small footprint and good intrinsic parameters (low Rdson and low parasitic capacitors). R&T activities have been done in cooperation with CNES (French Space Agency) to introduce GaN HFET, to put in place the screening process and to highlight the operating margins for space application. As the GaN HFET are massively produced for terrestrial applications, their intrinsic cost makes them attractive, even when space grade qualification has to be done (encapsulation in a hermetic package, screening, testing, burn-in …). Based on this work, Thales Alenia Space has developed and qualified a new generation of DC/DC converter for digital core using GaN HFET and is compared to a radiation hardened MOSFET solution.","PeriodicalId":6734,"journal":{"name":"2019 European Space Power Conference (ESPC)","volume":"72 1","pages":"1-3"},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91022692","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-09-01DOI: 10.1109/ESPC.2019.8932055
H. Carbonnier, C. Delepaut
Average Current Control (AAC) or Conductance Control has been widely used in the European space sector for the last three decades. Although very common in DC/DC converters inside Power Conditioning and Distribution Units (PCDU), until recently no attempt was made to characterize and understand the effects of the sampling that occurs when the controlled current is compared to the sawtooth signal. Indeed, similar sampling phenomena exist with the widespread Peak Current Control scheme (PCC) and have been well documented in the literature. Recently, it has been demonstrated that not only the same sampling effects exist for ACC, but that ACC with asymmetrical sawtooth can be seen as being the same control scheme as PCC with its compensation ramp, the sole difference being the slope of the controlled current with respect to the sawtooth slope. In addition, a new scheme called Peak and Valley Current Control (PVCC) has been proposed, with the observation that ACC with symmetrical sawtooth is also a subset of PVCC. The aim of this paper is to provide a comparison between PCC and PVCC, to highlight the similarities between those schemes and ACC, and to verify experimentally the above-mentioned findings.
{"title":"Experimental Demonstration of Peak and Valley Current Control","authors":"H. Carbonnier, C. Delepaut","doi":"10.1109/ESPC.2019.8932055","DOIUrl":"https://doi.org/10.1109/ESPC.2019.8932055","url":null,"abstract":"Average Current Control (AAC) or Conductance Control has been widely used in the European space sector for the last three decades. Although very common in DC/DC converters inside Power Conditioning and Distribution Units (PCDU), until recently no attempt was made to characterize and understand the effects of the sampling that occurs when the controlled current is compared to the sawtooth signal. Indeed, similar sampling phenomena exist with the widespread Peak Current Control scheme (PCC) and have been well documented in the literature. Recently, it has been demonstrated that not only the same sampling effects exist for ACC, but that ACC with asymmetrical sawtooth can be seen as being the same control scheme as PCC with its compensation ramp, the sole difference being the slope of the controlled current with respect to the sawtooth slope. In addition, a new scheme called Peak and Valley Current Control (PVCC) has been proposed, with the observation that ACC with symmetrical sawtooth is also a subset of PVCC. The aim of this paper is to provide a comparison between PCC and PVCC, to highlight the similarities between those schemes and ACC, and to verify experimentally the above-mentioned findings.","PeriodicalId":6734,"journal":{"name":"2019 European Space Power Conference (ESPC)","volume":"42 1","pages":"1-7"},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80881649","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-09-01DOI: 10.1109/ESPC.2019.8932026
I. García, I. Rey‐Stolle, M. Hinojosa, I. Lombardero, L. Cifuentes, C. Algora, H. Nguyen, A. Morgan, Andrew J. Johnson
Virtual substrates based on thin Ge layers on Si substrates by direct deposition have recently achieved high quality. In this work, their application as low cost, removable substrates for the growth of high efficiency, lightweight and flexible multijunction solar cells for space applications is analyzed. Experimental Ge single-junction solar cells and GaInP/Ga(In)As/Ge triple-junction solar cells using the Ge/Si virtual substrate as an active bottom junction (being the Si inactive), are implemented using medium quality Ge/Si virtual substrates with a $5 boldsymbol{mu} mathbf{m}$ Ge layer thickness. A lower quality in the Ge material, as compared to standard substrates, but enough carrier collection efficiency for a standard triple-junction, are shown. The expected formation of cracks during growth, due to the large thermal expansion coefficient mismatch with the Si substrate, is confirmed, and is found to be a major limiting factor for the performance of the solar cells. Strategies such as thinning the Ge + III-V structure and minimizing the thermal cycling during growth are discussed. Using an embedded porous Si layer to serve as buffer for the strain is being investigated. This porous layer could also serve as sacrificial layer for high throughput mechanical epitaxial lift-off in the manufacturing of lightweight and flexible multijunction cells. These embedded porous Si layers need to be engineered for optimum performance and compatibility with the Ge and III-V deposition processes.
{"title":"Space III-V Multijunction Solar Cells on Ge/Si virtual substrates","authors":"I. García, I. Rey‐Stolle, M. Hinojosa, I. Lombardero, L. Cifuentes, C. Algora, H. Nguyen, A. Morgan, Andrew J. Johnson","doi":"10.1109/ESPC.2019.8932026","DOIUrl":"https://doi.org/10.1109/ESPC.2019.8932026","url":null,"abstract":"Virtual substrates based on thin Ge layers on Si substrates by direct deposition have recently achieved high quality. In this work, their application as low cost, removable substrates for the growth of high efficiency, lightweight and flexible multijunction solar cells for space applications is analyzed. Experimental Ge single-junction solar cells and GaInP/Ga(In)As/Ge triple-junction solar cells using the Ge/Si virtual substrate as an active bottom junction (being the Si inactive), are implemented using medium quality Ge/Si virtual substrates with a $5 boldsymbol{mu} mathbf{m}$ Ge layer thickness. A lower quality in the Ge material, as compared to standard substrates, but enough carrier collection efficiency for a standard triple-junction, are shown. The expected formation of cracks during growth, due to the large thermal expansion coefficient mismatch with the Si substrate, is confirmed, and is found to be a major limiting factor for the performance of the solar cells. Strategies such as thinning the Ge + III-V structure and minimizing the thermal cycling during growth are discussed. Using an embedded porous Si layer to serve as buffer for the strain is being investigated. This porous layer could also serve as sacrificial layer for high throughput mechanical epitaxial lift-off in the manufacturing of lightweight and flexible multijunction cells. These embedded porous Si layers need to be engineered for optimum performance and compatibility with the Ge and III-V deposition processes.","PeriodicalId":6734,"journal":{"name":"2019 European Space Power Conference (ESPC)","volume":"22 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76885003","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-09-01DOI: 10.1109/ESPC.2019.8932040
S. Riva, E. F. Lisbona, C. Baur, Francesco Faleg, P. Zanella, Paolo Fidanzati, S. van Riesen, A. Gras, Richard Schmidt, M. Kroon, E. Bongers
The JUICE (JUpiter ICy moon Explorer) mission is characterized by a severe environmental condition, as the spacecraft will mainly operate in the Jovian region of the solar system. Low intensity, low temperatures and high radiation doses are the challenging factors for the solar array and especially for the photovoltaic assembly. Following a technology research program [1], the $3mathrm{G}28$ bare solar cell by Azur Space has been selected; moreover, dedicated acceptance criteria were defined to screen the devices for highest and predictable performance under the harsh Jovian condition. Leonardo has then started a pre-qualification at solar cell and protection diode assembly level (cell and diode with coverglass and interconnectors). This pre-qualification identified the technology to be finally tested in accordance to the relevant ECSS standard, specifically including also a test in low intensity low temperature (LILT) condition also for the full-scale photovoltaic assembly qualification model.
{"title":"Low Intensity Low Temperature / dark measurement campaign for the JUICE Photovoltaic Assembly - from solar cell to full-scale qualification model","authors":"S. Riva, E. F. Lisbona, C. Baur, Francesco Faleg, P. Zanella, Paolo Fidanzati, S. van Riesen, A. Gras, Richard Schmidt, M. Kroon, E. Bongers","doi":"10.1109/ESPC.2019.8932040","DOIUrl":"https://doi.org/10.1109/ESPC.2019.8932040","url":null,"abstract":"The JUICE (JUpiter ICy moon Explorer) mission is characterized by a severe environmental condition, as the spacecraft will mainly operate in the Jovian region of the solar system. Low intensity, low temperatures and high radiation doses are the challenging factors for the solar array and especially for the photovoltaic assembly. Following a technology research program [1], the $3mathrm{G}28$ bare solar cell by Azur Space has been selected; moreover, dedicated acceptance criteria were defined to screen the devices for highest and predictable performance under the harsh Jovian condition. Leonardo has then started a pre-qualification at solar cell and protection diode assembly level (cell and diode with coverglass and interconnectors). This pre-qualification identified the technology to be finally tested in accordance to the relevant ECSS standard, specifically including also a test in low intensity low temperature (LILT) condition also for the full-scale photovoltaic assembly qualification model.","PeriodicalId":6734,"journal":{"name":"2019 European Space Power Conference (ESPC)","volume":"22 1","pages":"1-7"},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88350374","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-09-01DOI: 10.1109/ESPC.2019.8931978
A. Beutl, Ningxin Zhang, Marcus Jahn, M. Nestoridi
The paper reports the investigations performed in the course of the ESA TRP activity (Contract No. 4000123997/18/NL/HK) on the use of solid polymer electrolytes for safe lithium ion batteries for clean space. The objective is to develop 1Ah prototype pouch cells without using any volatile liquid component. The exchange of conventional, highly flammable electrolytes with solid Li+-conducting polymers significantly improves the electrochemical and thermal stability range of the battery cells. Thereby fragmentation events, and thus propagation of space debris, caused by battery malfunction can be mitigated. In the presented work, filled polymer electrolytes were investigated for potential use in all-solid-state lithium-ion batteries. The polyethylene oxide-based polymer phase was either mixed with a lithium-ion conducting glass-ceramic (active) or BaTiO3 (passive) filler resulting in self-sustaining solid electrolyte membranes. Furthermore, carbon anodes and NMC622 cathodes were optimized to enable the assembly of full cells with enhanced safety properties.
{"title":"All-solid state batteries for space exploration","authors":"A. Beutl, Ningxin Zhang, Marcus Jahn, M. Nestoridi","doi":"10.1109/ESPC.2019.8931978","DOIUrl":"https://doi.org/10.1109/ESPC.2019.8931978","url":null,"abstract":"The paper reports the investigations performed in the course of the ESA TRP activity (Contract No. 4000123997/18/NL/HK) on the use of solid polymer electrolytes for safe lithium ion batteries for clean space. The objective is to develop 1Ah prototype pouch cells without using any volatile liquid component. The exchange of conventional, highly flammable electrolytes with solid Li+-conducting polymers significantly improves the electrochemical and thermal stability range of the battery cells. Thereby fragmentation events, and thus propagation of space debris, caused by battery malfunction can be mitigated. In the presented work, filled polymer electrolytes were investigated for potential use in all-solid-state lithium-ion batteries. The polyethylene oxide-based polymer phase was either mixed with a lithium-ion conducting glass-ceramic (active) or BaTiO3 (passive) filler resulting in self-sustaining solid electrolyte membranes. Furthermore, carbon anodes and NMC622 cathodes were optimized to enable the assembly of full cells with enhanced safety properties.","PeriodicalId":6734,"journal":{"name":"2019 European Space Power Conference (ESPC)","volume":"82 4 1","pages":"1-8"},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73147707","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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