330 results on '"Castellazzi, Alberto"'
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2. Multi-source energy networks for cargo Vessels
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Ahmed, Sanjana, Castellazzi, Alberto, Williams, Arthur, Ahmed, Sanjana, Castellazzi, Alberto, and Williams, Arthur
- Abstract
The paper discusses the feasibility of installing renewable energy generation technologies on sea-going transport, taking into account the additional weight and power consumption. This study in based on the power management of a 26,198 tonne commercial chemical tanker. The management system would aim at reducing the number of generators as well as the power required from burning fossil fuels. After a process of elimination of potential technologies based on feasibility of the project and shipboard application, the work is focused towards photovoltaic and wind energy generation in combination with fossil fueled engines and Li-ion battery storage covering the higher energy density needs, and the intermittent nature of renewables. The network architecture is optimized in order to have the highest efficiency, and reduced system weight. The results show that successful management of the system can lead to reduction in generator requirement, and energy despite the weight of extra installations of photovoltaic and wind energy generation systems. By reducing the number of generators and allowing each remaining one to operate near their maximum power, the specific fuel consumption is improved, the efficiency is increased, resulting in significant fuel and cost saving, along with the mass of fuel to be carried on-board.
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- 2016
3. Multi-source energy networks for cargo Vessels
- Author
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Ahmed, Sanjana, Castellazzi, Alberto, Williams, Arthur, Ahmed, Sanjana, Castellazzi, Alberto, and Williams, Arthur
- Abstract
The paper discusses the feasibility of installing renewable energy generation technologies on sea-going transport, taking into account the additional weight and power consumption. This study in based on the power management of a 26,198 tonne commercial chemical tanker. The management system would aim at reducing the number of generators as well as the power required from burning fossil fuels. After a process of elimination of potential technologies based on feasibility of the project and shipboard application, the work is focused towards photovoltaic and wind energy generation in combination with fossil fueled engines and Li-ion battery storage covering the higher energy density needs, and the intermittent nature of renewables. The network architecture is optimized in order to have the highest efficiency, and reduced system weight. The results show that successful management of the system can lead to reduction in generator requirement, and energy despite the weight of extra installations of photovoltaic and wind energy generation systems. By reducing the number of generators and allowing each remaining one to operate near their maximum power, the specific fuel consumption is improved, the efficiency is increased, resulting in significant fuel and cost saving, along with the mass of fuel to be carried on-board.
- Published
- 2016
4. Novel current-limiting strategy for solid-state circuit breakers (SSCB) without additional impedance
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Gu, Chunyang, Effah, Francis Boafo, Castellazzi, Alberto, Watson, Alan James, Wheeler, Patrick, Gu, Chunyang, Effah, Francis Boafo, Castellazzi, Alberto, Watson, Alan James, and Wheeler, Patrick
- Abstract
Current-limiting strategies for solid-state circuit breaker (SSCB) without adding impedance is introduced in this paper. With the current limitation of novel phase-shifting method, the advantages are simple hardware structure, relatively low cost, no heat generation, low weight and small size. Current-limiting capability is exploited with qualities of good control accuracy and robustness. The principle and theoretical analysis of phase-shifting current-limiting method are detailed introduced together with simulation/experimental verifications.
5. Device loss model of a fully SiC based dual active bridge considering the effect of synchronous rectification and deadtime
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Wang, Zhenyu, Castellazzi, Alberto, Wang, Zhenyu, and Castellazzi, Alberto
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It is becoming a great interest to employ SiC based power devices in dual active bridge (DAB) converter as an alternative to conventional Si-IGBT, due to its higher switching frequency potential, smaller switching losses as well as the capability to operate at synchronous rectification (SR) condition. This paper introduces the device loss model of a SiC MOSFET power module based DAB converter considering the effect of synchronous rectification, and the dead-time effect is also discussed. The calculated device loss for both SiC-MOSFET and Si-IGBT are discussed. The results show that the overall device loss is reduced by 40%, where the conduction loss is reduced by 38% because of SR capability of SiC-MOSFET, and the switching loss is reduced by 48% due to the faster transient of SiC-MOSFET during dead-time. On the other hand, the device losses are not even between the primary bridge and the secondary bridge of the DAB converter, and it is more significant for SiC-MOSFET based DAB due to the effect of SR with a maximum of 20%. At last, the dead-time range is given based on the device properties.
6. Dynamic performance analysis of a 3.3 kV SiC MOSFET half-bridge module with parallel chips and body-diode freewheeling
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Hussein, Abdallah, Mouawad, Bassem, Castellazzi, Alberto, Hussein, Abdallah, Mouawad, Bassem, and Castellazzi, Alberto
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Recently, 3.3 and 6.5 kV power MOSFETs have been introduced. Based on the 3.3 kV device, a 100 A half-bridge power module has been developed, using parallel chips for current scaling and relying exclusively on the use of the transistors body-diode for current free-wheeling (i.e., no antiparallel external diode chips are used). This paper presents a thorough parametric characterization of the module switching performance. Single-chip and parallel-chip operation are investigated in both double-pulsea type tests and realistic singlephase inverter operation.
7. Experimental demonstration of an optimised PWM scheme for more even device electro-thermal stress in a 3-Level ANPC GaN inverter
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Zeng, Y., Gurpinar, Emre, Hussein, A., Castellazzi, Alberto, Zeng, Y., Gurpinar, Emre, Hussein, A., and Castellazzi, Alberto
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GaN device as one potential power electronics device has been gained much attention recently. One of the power conversion systems, ANPC inverter using GaN HEMT is potentially considered to be prospective usage of low loss and high efficiency. In this work, we demonstrate one optimised PWM scheme aims at balancing the device electro-thermal stress based on Parma PWM to control 3-Level ANPC GaN inverter. The method is to decrease the loss for switches account for the large loss and increase the loss for switches with less thermal stress initially. The simulation and experimental results prove the effectiveness of the optimised PWM in controlling the loss distribution.
8. Static and dynamic TSEPs of SiC and GaN transistors
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Zhu, Siwei, Fayyaz, Asad, Castellazzi, Alberto, Zhu, Siwei, Fayyaz, Asad, and Castellazzi, Alberto
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This paper investigates the static and dynamic temperature sensitive electrical parameters (TSEPs) for both SiC and GaN transistors. It is shown that both the qualitative and quantitative temperature characteristics of these parameters are various when different type of transistors are concerned. This finding can be used to select the most appropriate temperature sensitive parameter for the device under specific situation. In this paper, two types of transistors, SiC SCT2080KE MOSFET and GaN PGA26E19BA HEMT are evaluated and compared in terms of six TSEPs, including source-drain reverse bias voltage (VSD), static on-resistance (RDS,ON), gate threshold voltage (VGS(TH)), transconductance (gm), dIDS/dt switching transients and gate current (IG). Then, these TSEPs are compared using four criteria: temperature sensitivity, linearity, material and the capability of on-line temperature monitoring
9. Tradeoff study of heat sink and output filter volume in a GaN HEMT based single-phase inverter
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Gurpinar, Emre, Castellazzi, Alberto, Gurpinar, Emre, and Castellazzi, Alberto
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This paper presents the trade-off study of heat sink and output filter volume of a GaN HEMT based single phase inverter. The selected topology is three-level Active Neutral point Clamped (ANPC) inverter, and the main aim is to explore the benefits of the GaN HEMTs at 600 V blocking class on the system level efficiency, and power density under wide range of operating conditions. The paper starts by introducing the inverter topology, selected PWM scheme and followed by the device features, static and dynamic characterisation and continues with presenting and discussing the results of extensive experimental and analytical characterisation. After this, the impact of GaN HEMTs on inverter volume is discussed in terms of heat sink and output filter volume analysis under different switching frequency and heat sink temperature conditions. The calculation of heat sink volume and single stage LC output filter volume are presented with respect to experimental results of single phase prototype. The findings from static, dynamic characterisation and single phase prototype results clearly show that GaN HEMT has excellent switching performance under wide load current and heat sink temperature conditions. The high performance of the inverter lead to reduction of the combined total volume, including output filter and heat sink volume.
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10. Co-design/simulation of flip-chip assembly for high voltage IGBT packages
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Rajaguru, P., Bailey, Christopher, Aliyu, Attahir Murtala, Castellazzi, Alberto, Pathirana, V., Udugampola, N., Trajkovic, T., Udrea, F., Mitchelson, P.D., Elliot, A.D.T., Rajaguru, P., Bailey, Christopher, Aliyu, Attahir Murtala, Castellazzi, Alberto, Pathirana, V., Udugampola, N., Trajkovic, T., Udrea, F., Mitchelson, P.D., and Elliot, A.D.T.
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This paper details a co-design and modelling methodology to optimise the flip-chip assembly parameters so that the overall package and system meets performance and reliability specifications for LED lighting applications. A co-design methodology is employed between device level modelling and package level modelling in order enhance the flow of information. As part of this methodology, coupled electrical, thermal and mechniacal predictions are made in order to mitigate underfill dielectric breakdown failure and solder interconnect fatigue failure. Five commercial underfills were selected for investigating the trade-off in materials properties that mitigate underfill electrical breakdown and solder joint fatigue.
11. Prognostic System for Power Modules in Converter Systems Using Structure Function
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Aliyu, Attahir Murtala, Castellazzi, Alberto, Aliyu, Attahir Murtala, and Castellazzi, Alberto
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This paper proposes an on-board methodology for monitoring the health of power converter modules in drive systems, using vector control heating and structure function to check for degradation. It puts forward a system that is used on-board to measure the cooling curve and derive the structure function during idle times for maintenance purposes. The structure function is good tool for tracking the magnitude and location of degradation in power modules. The ability to keep regular track of the actual degradation level of the modules enables the adoption of preventive maintenance, reducing or even eliminating altogether the appearance of failures during operation, significantly improving the availability of the power devices. The novelty in this work is the complete system that is used to achieve degradation monitoring; combining the heating technique and the measurement without additional power components except the measurement circuit which can be integrated into the gate drive board and the challenges encountered. Experimental results obtained from this show that it is possible to implement an on-board health monitoring system in converters which measures the degradation on power modules.
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12. Design of low inductance switching power cell for GaN HEMT based inverter
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Gurpinar, Emre, Iannuzzo, Francesco, Yang, Yongheng, Castellazzi, Alberto, Blaabjerg, Frede, Gurpinar, Emre, Iannuzzo, Francesco, Yang, Yongheng, Castellazzi, Alberto, and Blaabjerg, Frede
- Abstract
In this paper, an ultra-low inductance power cell is designed for a three-Level Active Neutral Point Clamped (3LANPC) based on 650 V gallium nitride (GaN) HEMT devices. The 3L-ANPC topology with GaN HEMT devices and the selected modulation scheme suitable for wide-bandgap (WBG) devices are presented. The commutation loops, which mainly contribute to voltage overshoots and increase of switching losses, are discussed. The ultra-low inductance power cell design based on a fourlayer Printed Circuit Board (PCB) with the aim to maximize the switching performance of GaN HEMTs is explained. The design of gate drivers for the GaN HEMT devices is presented. Parasitic inductance and resistance of the proposed design are extracted with finite element analysis and discussed. Commonmode behaviours based on the SPICE model of the converter are analyzed. Experimental results on the designed 3L-ANPC with the output power of up to 1 kW are presented, which verifies the performance of the proposed design in terms of ultra-low inductance.
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13. Trade-off study of heat sink and output filter volume in a GaN HEMT based single phase inverter
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Gurpinar, Emre, Castellazzi, Alberto, Gurpinar, Emre, and Castellazzi, Alberto
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This paper presents the trade-off study of heat sink and output filter volume of a GaN HEMT based single phase inverter. The selected topology is three-level Active Neutral point Clamped (ANPC) inverter, and the main aim is to explore the benefits of the GaN HEMTs at 600 V blocking class on the system level efficiency, and power density under wide range of operating conditions. The paper starts by introducing the inverter topology, selected PWM scheme and followed by the device features, static and dynamic characterisation and continues with presenting and discussing the results of extensive experimental and analytical characterisation. After this, the impact of GaN HEMTs on inverter volume is discussed in terms of heat sink and output filter volume analysis under different switching frequency and heat sink temperature conditions. The calculation of heat sink volume and single stage LC output filter volume are presented with respect to experimental results of single phase prototype. The findings from static, dynamic characterisation and single phase prototype results clearly show that GaN HEMT has excellent switching performance under wide load current and heat sink temperature conditions. The high performance of the inverter lead to reduction of the combined total volume, including output filter and heat sink volume.
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14. Optimization of thermal management and power density of small-scale wind turbine applications using SiC-MOSFETs
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Hussein, Abdallah, Castellazzi, Alberto, Hussein, Abdallah, and Castellazzi, Alberto
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This paper presents an optimized design of 12kW 2L-FB inverter for small-scale wind turbine, taking into account some specific behavioral features of SiC power MOSFETs. Power converters used in renewable energy conversion have to deal with intermittent and variable power availability from the source, which implies that they actually work at their maximum rated power for only a small fraction of their operational time. Still, traditional thermal management design of power modules has to refer to maximum load conditions. SiC-MOSFETs exhibit a very stable performance over a broad temperature range [1-3]; this feature enables to design the cooling device for nominal operational conditions, typically corresponding to a much lower than maximum power rating. When this capability is added to the decrease in the size of passive filter elements, which can be gained by the higher switching frequency capability of SiC MOSFETs, the result is a significant increase of the converter powe, density.
15. Influence of gate bias on the avalanche ruggedness of SiC power MOSFETs
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Fayyaz, Asad, Castellazzi, Alberto, Romano, G., Riccio, M., Urresti, J., Wright, N., Fayyaz, Asad, Castellazzi, Alberto, Romano, G., Riccio, M., Urresti, J., and Wright, N.
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This paper investigates the effect of negative gate bias voltage (VGS) on the avalanche breakdown robustness of commercial state-of-the-art silicon carbide (SiC) power MOSFETs. The device’s ability to withstand energy dissipation during avalanche regime is a connoting figure of merit for all applications requiring load dumping and/or benefiting from snubber-less converter design. The superior material properties of SiC material means that SiC MOSFETs even at 1200V exhibit significant intrinsic avalanche robustness.
16. Experimental study of the short-circuit performance for a 600V normally-off p-gate GaN HEMT
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Oeder, Thorsten, Castellazzi, Alberto, Pfost, Martin, Oeder, Thorsten, Castellazzi, Alberto, and Pfost, Martin
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In this paper, the short-circuit robustness of a normally off GaN HEMT is investigated in relation to applied bias conditions and pulse duration. The results align with previous studies on normally-on devices in highlighting an electrical type of failure. Here, however, the relevance of the specific gate-drive circuit design and corresponding device operational condtions is demonstrated. A gate-bias dependence (GBD) of the failure, correlated to the applied drain-source voltage, is introduced as a novel specific feature for the p-Gate type device.
17. Modular assembly of a single phase inverter based on integrated functional block
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Castellazzi, Alberto, Solomon, Adane Kassa, Delmonte, N., Cova, P., Castellazzi, Alberto, Solomon, Adane Kassa, Delmonte, N., and Cova, P.
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This paper presents an original modular plug-in type assembly approach for a single phase-inverter. The main focus here is, indicatively, on the power range 1-20 kW, but the methodology can be transferred to higher power levels, too. At the core of the inverter lies a power-dense double-sided-cooled half-bridge power switch architecture with integrated cooler, which is interconnected to filter elements, gate-driver and control circuitry by means of compact flat connectors. The integration exercise targets, on the one hand, the optimization of the power switch performance and reliability, as well as the reduction of circuit parasitic elements; on the other, the production of a system compatible with maintenance and repairing, featuring minimized impact of single component failure on the system maintenance and repair cost and thus on its availability. Preliminary experimental tests demonstrate the nominal functionality of the inverter.
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18. Pressure contact multi-chip packaging of SiC Schottky diodes
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Gonzalez, Jose Ortiz, Alatise, Olayiwola, Mawby, Philip, Aliyu, Attahir Murtala, Castellazzi, Alberto, Gonzalez, Jose Ortiz, Alatise, Olayiwola, Mawby, Philip, Aliyu, Attahir Murtala, and Castellazzi, Alberto
- Abstract
Pressure contact packages have demonstrated an improved reliability for silicon devices due to the elimination of the weak elements of the packaging, namely wirebonds and solder. This packaging approach has not yet been widely studied for SiC devices, however, it is of high interest for applications like HVDC or rail traction, where the wide bandgap properties of SiC devices can be fully exploited and high reliability is critical. Current IGBT press-pack modules use Si PiN diodes for enabling reverse conduction, however, the use of SiC Schottky diodes would be beneficial given their better characteristics including low switching losses and lower zero temperature coefficient (ZTC) for electrothermal stability of diodes in parallel. A prototype for the evaluation of SiC Schottky diodes using pressure contacts has been designed, built and tested for both single die and multiple die.
19. Chip-on-board assembly of 800V Si L-IGBTs for high performance ultra-compact LED drivers
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Aliyu, Attahir Murtala, Mouawad, Bassem, Castellazzi, Alberto, Rajaguru, P., Bailey, C., Pathirana, V., Udugampola, N., Trajkovic, T., Udrea, F., Aliyu, Attahir Murtala, Mouawad, Bassem, Castellazzi, Alberto, Rajaguru, P., Bailey, C., Pathirana, V., Udugampola, N., Trajkovic, T., and Udrea, F.
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This paper presents a novel chip on board assembly design for an integrated power switch, based on high power density 800V silicon lateral insulated-gate bipolar transistor (Si LIGBT) technology. LIGBTs offer much higher current densities (5-10X), significantly lower leakage currents, and lower parasitic device capacitances and, gate charge compared to conventional vertical MOSFETs commonly used in LED drivers. The higher voltage ratings offered (up to 1kV), the development of high voltage interconnection between parallel IGBTs, self-isolated nature and absence of termination region unlike in a vertical MOSFET makes these devices ideal for ultra-compact, low bill of materials (BOM) count LED drives. Chip on-board LIGBTs also offer significant advantages over MOSFETs due to high ambient temperatures seen on most of the LED lamps as the LIGBTs on-state losses increase only marginally with temperature. The design is based on a built-in reliability approach which focuses on a compact LED driver as a case-study of a cost-sensitive large volume production item.
20. Modular integrated SiC MOSFET matrix converter
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Aliyu, Attahir Murtala, Castellazzi, Alberto, Lasserre, Philippe, Delmonte, N., Aliyu, Attahir Murtala, Castellazzi, Alberto, Lasserre, Philippe, and Delmonte, N.
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This paper presents the assembly and characterization of an integrated all SiC 3-to-1 phases matrix converter, of typical application in domains requiring harsh environment withstand capability with high reliability and availability levels (e.g., renewable energies, solid-state transformation, smart grids, electric transport). Commercially available silicon-carbide (SiC) power MOSFETs are procured in bare-die form to develop custom-packaged bi-directional switches, with an advanced approach aiming to optimize the electro-thermal and electro-magnetic performance at switch level. Advanced cooling and packaging solutions at system level enable modularity with reduced impact of single component failure on the overall system, contributing to significantly reduced maintenance and repair costs.
21. Evaluation of SiC Schottky diodes using pressure contacts
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Ortiz Gonzalez, J., Alatise, O., Aliyu, Attahir Murtala, Rajaguru, Pushparajah, Castellazzi, Alberto, Ran, L., Mawby, P., Bailey, Christopher, Ortiz Gonzalez, J., Alatise, O., Aliyu, Attahir Murtala, Rajaguru, Pushparajah, Castellazzi, Alberto, Ran, L., Mawby, P., and Bailey, Christopher
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The thermomechanical reliability of SiC power devices and modules is increasingly becoming of interest especially for high power applications where power cycling performance is critical. Press-pack assemblies are a trusted and reliable packaging solution that has traditionally been used for high power thyristorbased applications in FACTS/HVDC, although press-pack IGBTs have become commercially available more recently. These press-pack IGBTs require anti-parallel PiN diodes for enabling reverse conduction capability. In these high power applications, paralleling chips for high current conduction capability is a requirement, hence, electrothermal stability during current sharing is critical. SiC Schottky diodes not only exhibit the advantages of wide bandgap technology compared to silicon PiN diodes, but they have significantly lower zero temperature coefficient (ZTC) meaning they are more electrothermally stable. The lower ZTC is due to the unipolar nature of SiC Schottky diodes as opposed to the bipolar nature of PiN diodes. This paper investigates the implementation and reliability of SiC Schottky diodes in press-pack assemblies. The impact of pressure loss on the electrothermal stability of parallel devices is investigated.
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22. Electrical and thermal failure modes of 600 V p-gate GaN HEMTs
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Oeder, Thorsten, Castellazzi, Alberto, Pfost, Martin, Oeder, Thorsten, Castellazzi, Alberto, and Pfost, Martin
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A study of electrical and thermal failure modes of 600 V p-doped GaN HEMTs is presented, which focuses on the investigation of short-circuit limitations. The electrical failure mode seems to be an electrical field breakdown in the structure which is caused by excessive carrier concentration, rather than primary thermal generated. Accordingly, a thermal failure mode is observed, which features a distinctive behaviour and seems to be similar to schottky-gate HEMTs. Concerning the electrical failure mode, a specific p-gate HEMT short-circuit safe operating area (SCSOA) is presented as a novelty. However, a short-circuit capability of up to 520 V can be achieved, regarding the design of the gate-drive circuit.
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23. A comprehensive study on the avalanche breakdown robustness of silicon carbide power MOSFETs
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Fayyaz, Asad, Romano, Gianpaolo, Urresti, Jesus, Riccio, Michele, Castellazzi, Alberto, Irace, Andrea, Wright, Nick, Fayyaz, Asad, Romano, Gianpaolo, Urresti, Jesus, Riccio, Michele, Castellazzi, Alberto, Irace, Andrea, and Wright, Nick
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This paper presents an in-depth investigation into the avalanche breakdown robustness of commercial state-of-the-art silicon carbide (SiC) power MOSFETs comprising of functional as well as structural characterization and the corresponding underlying physical mechanisms responsible for device failure. One aspect of robustness for power MOSFETs is determined by its ability to withstand energy during avalanche breakdown. Avalanche energy (EAV) is an important figure of merit for all applications requiring load dumping and/or to benefit from snubber-less converter design. 2D TCAD electro-thermal simulations were performed to get important insight into the failure mechanism of SiC power MOSFETs during avalanche breakdown
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24. Semiconductor devices in solid-state/hybrid circuit breakers: current status and future trends
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Gu, Chunyang, Wheeler, Pat, Castellazzi, Alberto, Watson, Alan J., Effah, Francis, Gu, Chunyang, Wheeler, Pat, Castellazzi, Alberto, Watson, Alan J., and Effah, Francis
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Circuit breakers (CBs) are the main protection devices for both alternating current (AC) and direct current (DC) power systems, ranging from tens of watts up to megawatts. This paper reviews the current status for solid-state circuit breakers (SSCBs) as well as hybrid circuit breakers (HCBs) with semiconductor power devices. A few novel SSCB and HCB concepts are described in this paper, including advantage and limitation discussions of wide-band-gap (WBG) devices in basic SSCB/HCB configuration by simulation and 360 V/150 A experimental verifications. Novel SSCB/HCB configurations combining ultra-fast switching and high efficiency at normal operation are proposed. Different types of power devices are installed in these circuit breakers to achieve adequate performance. Challenges and future trends of semiconductor power devices in SSCB/HCB with different voltage/power levels and special performance requirements are clarified.
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25. Thermal design and characterization of a modular integrated liquid cooled 1200 V-35 A SiC MOSFET bi-directional switch
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Cova, P., Aliyu, Attahir Murtala, Castellazzi, Alberto, Chiozzi, D., Delmonte, N., Lasserre, P., Pignoloni, N., Cova, P., Aliyu, Attahir Murtala, Castellazzi, Alberto, Chiozzi, D., Delmonte, N., Lasserre, P., and Pignoloni, N.
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The aim of this work is the thermal design of a modular direct liquid cooled package for 1200 V–35 A SiC power MOSFETs, in order to take full advantage of the high power density and high frequency performance of these devices, in the development of a modular integrated solution for power converters. An accurate electro-thermal fluid dynamic model is set up and validated by thermal characterization on a prototype; numerical models have been used to study the internal temperature distribution and to propose further optimization.
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26. 3.3 kV SiC JBS diode configurable rectifier module
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Mouawad, Bassem, Wang, Zhenyu, Buettner, J., Castellazzi, Alberto, Mouawad, Bassem, Wang, Zhenyu, Buettner, J., and Castellazzi, Alberto
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This paper presents the use of innovative high-voltage SiC diode technology in the development of a user configurable full-wave or half-wave rectifier bridge. The devices are of merged Junction-Barrier-Schottky (JBS) type to enable for optimum performance even in the presence of current surges, as demanded by the application. To contain the cost of the proposed solution, their packaging relies on Insulated Metal Substrates (IMS), as opposed to conventional ceramic type substrates. The layout and module pin terminations are chosen to yield optimum electro-thermal and electro-magnetic performance in compatibility with a standard solder and wire-bond assembly process. Preliminary functional static characterization tests at different temper¬atures are also presented.
27. Testing of a lightweight SiC power module for avionic applications
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Gurpinar, Emre, Lopez Arevalo, Saul, Li, Jianfeng, De, D., Castellazzi, Alberto, Mills, Liam, Gurpinar, Emre, Lopez Arevalo, Saul, Li, Jianfeng, De, D., Castellazzi, Alberto, and Mills, Liam
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Functional and performance tests of a three-phase, two-level power module based on CREE 1.2kV SiC MOSFETs for avionic applications is presented in this paper. SiC devices have superior properties over conventional Si devices at high voltage operations and these properties make SiC devices at-tractive for avionic industry in order to reduce size of power electronic converters while maintaining high efficiency. This paper starts with a brief explanation of thermo-mechanical de¬sign approach of SiC power module. Thermo-mechanical de¬sign is followed by test setup and experimental results for dif¬ferent load and switching frequency conditions. The module is tested up to 540V DC link voltage, 6kW output power with 100kHz switching frequency. Experimental results show that the module can be successfully operated with high efficiency at high switching frequencies.
28. Built-in reliability design of a high-frequency SiC MOSFET power module
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Li, Jianfeng, Gurpinar, Emre, Lopez Arevalo, Saul, Castellazzi, Alberto, Mills, Liam, Li, Jianfeng, Gurpinar, Emre, Lopez Arevalo, Saul, Castellazzi, Alberto, and Mills, Liam
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A high frequency SiC MOSFET-based three-phase, 2-level power module has been designed, simulated, assembled and tested. The design followed a built-in reliability approach, involving extensive finite-element simulation based analysis of the electro-thermo-mechanical strain and stress affecting the switch during both manufacturing and operation: structural simulations were carried out to identify the materials, geometry and sizes of constituent parts which would maximize reliability. Following hardware development, functional tests were carried out, showing that the module is suitable for high switching frequency operation without impairing efficiency, thus enabling a considerable reduction of system-level size and weight.
29. Transient out-of-SOA robustness of SiC power MOSFETs
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Castellazzi, Alberto, Fayyaz, Asad, Romano, Gianpaolo, Riccio, Michele, Irace, Andrea, Urresti-Ibanez, Jesus, Wright, Nick, Castellazzi, Alberto, Fayyaz, Asad, Romano, Gianpaolo, Riccio, Michele, Irace, Andrea, Urresti-Ibanez, Jesus, and Wright, Nick
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Beyond their main function of high-frequency switches in modulated power converters, solid-state power devices are required in many application domains to also ensure robustness against a number of overload operational conditions. This paper considers the specific case of 1200 V SiC power MOSFETs and analyses their performance under three main transient regimes at the edge of and out of their Safe Operating Area: unclamped inductive switching led avalanche breakdown; short-circuit; operation as current limiting and regulating devices. The results presented highlight both inherent major strengths of SiC over Si and areas for improvement by tailored device design. The paper aims to contribute useful indications for technology development in future device generations to better match widespread and varied application requirements.
30. Development and characterisation of pressed packaging solutions for high-temperature high-reliability SiC power modules
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Ortiz Gonzalez, J., Aliyu, Attahir Murtala, Alatise, O., Castellazzi, Alberto, Ran, L., Mawby, P., Ortiz Gonzalez, J., Aliyu, Attahir Murtala, Alatise, O., Castellazzi, Alberto, Ran, L., and Mawby, P.
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SiC is a wide bandgap semiconductor with better electrothermal properties than silicon, including higher temperature of operation, higher breakdown voltage, lower losses and the ability to switch at higher frequencies. However, the power cycling performance of SiC devices in traditional silicon packaging systems is in need of further investigation since initial studies have shown reduced reliability. These traditional packaging systems have been developed for silicon, a semiconductor with different electrothermal and thermomechanical properties from SiC, hence the stresses on the different components of the package will change. Pressure packages, a packaging alternative where the weak elements of the traditional systems like wirebonds are removed, have demonstrated enhanced reliability for silicon devices however, there has not been much investigation on the performance of SiC devices in press-pack assemblies. This will be important for high power applications where reliability is critical. In this paper, SiC Schottky diodes in pressure packages have been evaluated, including the electrothermal characterisation for different clamping forces and contact materials, the thermal impedance evaluation and initial thermal cycling studies, focusing on the use of aluminium graphite as contact material.
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31. A physical RC network model for electro-thermal analysis of a multichip SiC power module
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Li, Jianfeng, Castellazzi, Alberto, Eleffendi, Mohd Amir, Gurpinar, Emre, Johnson, Christopher Mark, Mills, Liam, Li, Jianfeng, Castellazzi, Alberto, Eleffendi, Mohd Amir, Gurpinar, Emre, Johnson, Christopher Mark, and Mills, Liam
- Abstract
This paper is concerned with the thermal models which can physically reflect the heat-flow paths in a lightweight three-phase half bridge, two-level SiC power module with 6 MOSFETs and can be used for coupled electro-thermal simulation. The finite element (FE) model was first evaluated and calibrated to provide the raw data for establishing the physical RC network model. It was experimentally verified that the cooling condition of the module mounted on a water cooler can be satisfactorily described by assuming the water cooler as a heat exchange boundary in the FE model. The compact RC network consisting of 115 R and C parameters to predict the transient junction temperatures of the 6 MOSFETS was constructed, where cross-heating effects between the MOSFETs are represented with lateral thermal resistors. A three-step curve fitting method was especially developed to overcome the challenge for extracting the R and C values of the RC network from the selected FE simulation results. The established compact RC network model can physically be correlated with the structure and heat-flow paths in the power module, and was evaluated using the FE simulation results from the power module under realistic switching conditions. It was also integrated into the LTspice model to perform the coupled electro-thermal simulation to predict the power losses and junction temperatures of the 6 MOSFETs under switching frequencies from 5 kHz to 100 kHz which demonstrate the good electro-thermal performance of the designed power module.
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32. Measuring structure functions of power devices in inverters
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Aliyu, Attahir Murtala, Castellazzi, Alberto, Aliyu, Attahir Murtala, and Castellazzi, Alberto
- Abstract
This paper proposes the measuring of structure function from power devices on-board induction motor drives and multilevel converters. It puts forward the issues and methodology related to on-board measurement of the cooling curve and derivation of the structure function during idle times in induction motor drives for maintenance purposes. The structure function uses the thermal resistances and capacitances in the Cauer form to identify changes in the device structure. The advantage of the structure function is that it does not only reveal the value but also the location of the thermal resistance and capacitance in the heat flow path. The novelty in this work is the methodology used to achieve the measurement of the cooling curve and obtaining the structure function despite issues related to freewheeling current due to energy stored as a result of motor inductance. A detailed description of the measurement circuit is presented. The possibility of applying this technique to multilevel converters in different application is also elaborated.
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33. High-frequency modulated secondary-side self-powered isolated gate driver for full range PWM operation of SiC power MOSFETs
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Garcia, Jorge, Gurpinar, Emre, Castellazzi, Alberto, Garcia, Jorge, Gurpinar, Emre, and Castellazzi, Alberto
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The present work proposes a solution for an isolated gate driver suitable for SiC MOSFETs. The driver is implemented by means of two small magnetic transformers, to provide the turn-on and turn-off gate signals, as well as the power required for an adequate gate control. The operation is based on the modulation of the PWM pulses with a high frequency (HF) square-waveform signal. The resulting modulated AC waveform is applied to the primary side of the first transformer, and reconstructed at the secondary side to obtain the gate driving signal. Simultaneously, the HF modulating signal is connected to the primary of the second transformer, to provide the required gate drive voltage levels and power at the secondary side, ensuring full range duty ratio operation. Given that both primary side signals are HF symmetrical waveforms, saturation is avoided at both transformers, for any duty ratio operation. Therefore, the proposed solution provides galvanic isolation for power and gate signal transfer with very small core sizes, allowing for an overall size reduction vs. conventional solutions. This enables much more compact designs, which are critical in high-power density applications and multilevel converters. After describing the basic operation, experimental results on a prototype are shown, thus demonstrating the feasibility of the proposed solution
34. Full SiC Version of the EDA5 Inverter
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Chowdhury, Shajjad, Gurpinar, Emre, Castellazzi, Alberto, Chowdhury, Shajjad, Gurpinar, Emre, and Castellazzi, Alberto
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Recently, a novel hybrid multilevel inverter topology, the EDA5, was presented. The novel inverter topology comprises of two floating capacitors and 16 active switches to achieve five-level output voltage waveform and achieves higher efficiency at low-modulation index compared to a five-level Active Neural Point Clamped (5L-ANPC) converter. In this work, a full SiC MOSFET version of the inverter is presented, using commercially available 1200V rated devices. A balanced mix of simulation and experimental results are presented to point out the salient features of the topology. The topology is compared with 5L-ANPC inverter in simulation, and experimentally demonstrated up to 12kW output power with 1kV DC link voltage.
35. Impact of SiC technology in a three-port active bridge converter for energy storage integrated solid state transformer applications
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Wang, Zhenyi, Castellazzi, Alberto, Saeed, Sarah, Navarro-Rodríguez, Ángel, Garcia, Pablo, Wang, Zhenyi, Castellazzi, Alberto, Saeed, Sarah, Navarro-Rodríguez, Ángel, and Garcia, Pablo
- Abstract
Silicon Carbide (SiC) MOSFET power module has become commercially available in the past few years, and it is attractive in solid state transformers (SSTs) applications to replace Silicon (Si)-based IGBTs. This paper is focused on the efficiency comparison between a SiC MOSFET-based three-port active bridge converter (TAB) and a Si IGBT-based approach. The efficiency of the overall system, being one of its ports connected to the energy storage element (Lithium-Ion battery), is tested and analyzed. By swapping the switching frequency of the device, a significant efficiency improvement can be observed by SiC power devices. Experimental results indicated that an efficiency increment of around 2% can be brought by SiC MOSFET. Moreover, the battery losses can be reduced by a maximum of 8% with the increased switching frequency.
36. Impulse transformer based secondary-side self-powered gate-driver for wide-range PWM operation of SiC power MOSFETs
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Garcia, Jorge, Gurpinar, Emre, Castellazzi, Alberto, Garcia, Jorge, Gurpinar, Emre, and Castellazzi, Alberto
- Abstract
This work proposes a solution for an isolated gate driver for SiC MOSFETs, based on a magnetic transformer that simultaneously provides to the secondary side the turn-on and turn-off gate signals and the power required for an adequate gate control. This avoids the use of a dedicated DC-DC isolated converter and optocoupler. The original pulse signal is converted into impulses, avoiding transformer saturation at any duty ratio operation. The small size of the resulting transformer enables an overall size reduction vs. conventional solutions (based either in magnetic or optocoupler + power supply). This enables much more compact designs, which are critical in high-power density applications and multilevel converters. After describing the basic operation of the driver, experimental results on a 2kW prototype demonstrate the feasibility of the proposal. It is worth mentioning that this design is also suitable for GaN devices with minor design changes
37. Integrated bi-directional SiC MOSFET power switches for efficient, power dense and reliable matrix converter assembly
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Lasserre, Philippe, Lambert, Donatien, Castellazzi, Alberto, Lasserre, Philippe, Lambert, Donatien, and Castellazzi, Alberto
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This paper presents an innovative device packaging and system integration approach aimed at optimizing the electro-thermal, electro-magnetic and thermo-mechanical performance of the switches in a power converter. In particular, the focus is on state-of-the-art commercially available silicon-carbide (SiC) power MOSFETs used within a matrix converter topology. The improvements at switch level over conventional packaging and integration solutions translate into higher efficiency, power density (in terms of volume and weight) and reliability at system level. In view of typical application domains (e.g., renewable energies, solid-state transformation, smart grids, electric transport), requiring harsh environment withstand capability with high reliability and availability levels, an AC-to-AC matrix converter is chosen as a particularly relevant case study. The paper also addresses two aspects of growing relevance: reliable manufacturability and preventive maintenance compatible modular system assembly for reduced impact of single component failure on system availability.
38. Silicon carbide MOSFETs in more electric aircraft power converters: the performance and reliability benefits over silicon IGBTs for a specified flight mission profile
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O'Donnell, Shane, Debauche, Jean-Louis, Wheeler, Patrick, Castellazzi, Alberto, O'Donnell, Shane, Debauche, Jean-Louis, Wheeler, Patrick, and Castellazzi, Alberto
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This paper describes the design, construction and performance of a 5 kVA aviation power module containing silicon carbide MOSFETs. The function and control of this module within a commercial aviation power electrical control unit (ECU) application is explained and the power dissipation benefits from the use of these MOSFETs instead of silicon IGBTs when driving an electrical motor controlling an aileron are presented. The paper shows the calculated reliability figures for the power module in this application and an application-specific reliability test to verify 150,000 flight hours of module operation is introduced. Performance test results from a prototype unit are also presented.
39. A survey on configurations of current-limiting circuit breakers (CL-CB)
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Gu, Chunyang, Wheeler, Patrick, Castellazzi, Alberto, Watson, Alan James, Effah, Francis Boafo, Gu, Chunyang, Wheeler, Patrick, Castellazzi, Alberto, Watson, Alan James, and Effah, Francis Boafo
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This paper presents a survey of topology configurations of current-limiting circuit breakers. Twelve different current-limiting topologies within four categories are detailed discussed and compared. It is concluded that active CL-CB may be a good choice for AC for its controllable reactive power capability to increase stability and multi-function protection.
40. Extracting structure functions of power devices in induction motor drives
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Aliyu, Attahir Murtala, Castellazzi, Alberto, Aliyu, Attahir Murtala, and Castellazzi, Alberto
- Abstract
This paper proposes the extraction of structure function from power devices on-board induction motor drives. It puts forward the issues and methodology related to on-board measurement of the cooling curve and derivation of the structure function during idle times in induction motor drives for maintenance purposes. The structure function uses the thermal resistances and capacitances in the Cauer form to identify changes in the device structure. The advantage of the structure function is that it does not only reveal the value but also the location of the thermal resistance and capacitance in the heat flow path. The novelty in this work is the methodology used to achieve the measurement of the cooling curve and the derivation of the structure function despite issues related to freewheeling current due to energy stored as a result of motor inductance.
41. UIS failure mechanism of SiC power MOSFETs
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Fayyaz, Asad, Castellazzi, Alberto, Romano, Gianpaolo, Riccio, Michele, Urresti, J., Wright, Nick, Fayyaz, Asad, Castellazzi, Alberto, Romano, Gianpaolo, Riccio, Michele, Urresti, J., and Wright, Nick
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This paper investigates the failure mechanism of SiC power MOSFETs during avalanche breakdown under unclamped inductive switching (UIS) test regime. Switches deployed within motor drive applications could experience undesired avalanche breakdown events. Therefore, avalanche ruggedness is an important feature of power devices enabling snubber-less converter design and is also a desired feature in certain applications such as automotive. It is essential to thoroughly characterize SiC power MOSFETs for better understanding of their robustness and more importantly of their corresponding underling physical mechanisms responsible for failure in order to inform device design and technology evolution. Experimental results during UIS at failure and 2D TCAD simulation results are presented in this study.
42. Performance benchmark of Si IGBTs vs. SiC MOSFETs in small-scale wind energy conversion systems
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Hussein, Abdallah, Castellazzi, Alberto, Wheeler, Patrick, Klumpner, Christian, Hussein, Abdallah, Castellazzi, Alberto, Wheeler, Patrick, and Klumpner, Christian
- Abstract
Modern power electronics devices based on SiC power MOSFETs technology become more demanding in the last few years. They show better performance over Si-IGBTs on renewable energy power conversion systems due to their higher switching frequency, higher temperature capability, higher power density and higher reliability. This paper presents a benchmarking of SiC-MOSFET and Si-IGBT power devices with the voltage rating of 1200V in 2-Level Full-Bridge (2L-FB) inverter for 10kW small scale wind turbine. By simulation, the inverter performance is evaluated in the presence of the wind speed distribution profile and the reference switching frequency value for SiC devices in this topology at this power level is determined. The results show that the SiC solution can improve the efficiency, save energy and reduce the size and cost due to high switching frequency and temperature capabilities.
43. Hybrid half-bridge package for high voltage application
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Mouawad, Bassem, Li, Jianfeng, Castellazzi, Alberto, Johnson, Christopher Mark, Mouawad, Bassem, Li, Jianfeng, Castellazzi, Alberto, and Johnson, Christopher Mark
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3D power module structures allow for better cooling and lower parasitic inductances compared with the classical planar technology. In this paper, we present a hybrid half-bridge in a 3D packaging configuration, dedicated for high voltage application. A dynamic electrical test of the package is presented.
44. Low inductance 2.5kV packaging technology for SiC switches
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Mouawad, Bassem, Li, Jianfeng, Castellazzi, Alberto, Johnson, Christopher Mark, Erlbacher, Tobias, Friedriches, Peter, Mouawad, Bassem, Li, Jianfeng, Castellazzi, Alberto, Johnson, Christopher Mark, Erlbacher, Tobias, and Friedriches, Peter
- Abstract
The switching speed of power semiconductors has reached levels where conventional semiconductors packages limit the achievable performance due to relatively high parasitic inductance and capacitance. This paper presents a novel packaging structure which employs stacked substrate and flexible printed circuit board (PCB) to obtain very low parasitic inductance and hence feature high switching speed SiC power devices. A half-bridge module aimed at blocking voltage up to 2.5kV has been designed to ac¬commodate 8 SiC JFETs and 4 SiC diodes. Electromagnetic simulation results reveal extremely low in¬ductance values of the major loops. Due to delay delivery of those custom ordered substrate and PCB, the prototyping samples of the designed module have yet been constructed. The up to date results including experimental construction, electrical and thermal performance of the samples will be presented at the conference.
45. Reliable integration of a high performance multi-chip half-bridge SiC power module
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Mouawad, Bassem, Li, Jianfeng, Castellazzi, Alberto, Johnson, Christopher Mark, Mouawad, Bassem, Li, Jianfeng, Castellazzi, Alberto, and Johnson, Christopher Mark
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Silicon carbide (SiC) devices have been adopted to push the boundaries further in terms of power density, conversion efficiency, switching speed or thermal capability. To have the benefit of such semiconductors, new packaging should be developed to meet all the advantages. In this paper, we present a reliable integrated concept of a new packaging solution for multi-chip SiC devices aiming to have a very low parasitic inductance in order to have high switching frequencies and ensure a good reliability for long-term operation.
46. Influence of design parameters on the short-circuit ruggedness of SiC Power MOSFETs
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Romano, Gianpaolo, Riccio, Michele, Maresca, Luca, Fayyaz, Asad, Castellazzi, Alberto, Romano, Gianpaolo, Riccio, Michele, Maresca, Luca, Fayyaz, Asad, and Castellazzi, Alberto
- Abstract
This work aims to present an investigation on short-circuit (SC) failure behaviour of SiC Power MOSFETs due to the onset of thermal runaway. As inferable from experimental outcomes, it is related to the formation of hotspot, whose exact location is mainly unpredictable and dictated by device structure and design parameters non-uniformities. TCAD simulations were performed to examine the impact of some parameters mismatch on hotspot formation and failure occurrence
47. Single-phase T-Type inverter performance benchmark Using Si IGBTs, SiC MOSFETs, and GaN HEMTs
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Gurpinar, Emre, Castellazzi, Alberto, Gurpinar, Emre, and Castellazzi, Alberto
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In this paper, benchmark of Si IGBT, SiC MOSFET and GaN HEMT power switches at 600V class is conducted in single-phase T-type inverter. Gate driver requirements, switching performance, inverter efficiency performance, heat sink volume, output filter volume and dead-time effect for each technology is evaluated. Gate driver study shows that GaN has the lowest gate driver losses above 100kHz and below 100kHz, SiC has lowest gate losses. GaN has the best switching performance among three technologies that allows high efficiency at high frequency applications. GaN based inverter operated at 160kHz switching frequency with 97.3% efficiency at 2.5kW output power. Performance of three device technologies at different temperature, switching frequency and load conditions shows that heat sink volume of the converter can be reduced by 2.5 times by switching from Si to GaN solution at 60°C case temperature, and for SiC and GaN, heat sink volume can be reduced by 2.36 and 4.92 times respectively by increasing heat sink temperature to 100°C. Output filter volume can be reduced by 43% with 24W, 26W and 61W increase in device power loss for GaN, SiC and Si based converters respectively. WBG devices allow reduction of harmonic distortion at output current from 3.5% to 1.5% at 100kHz.
48. Low parasitic inductance multi-chip SiC devices packaging technology
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Li, Jianfeng, Mouawad, Bassem, Castellazzi, Alberto, Friedrichs, Peter, Johnson, Christopher Mark, Li, Jianfeng, Mouawad, Bassem, Castellazzi, Alberto, Friedrichs, Peter, and Johnson, Christopher Mark
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This paper presents a novel packaging structure which employs stacked substrate and flexible printed circuit board (PCB) to obtain very low parasitic inductance and hence feature high switching speed SiC power devices. A half-bridge module aimed at blocking voltage up to 2.5kV has been designed to accommodate 8 SiC JFETs and 4 SiC diodes. Electromagnetic simulation results reveal extremely low inductance values of the major loops. Then the prototyping of the designed package including the assembly process, all the electrical test to evaluate the electrical performance are presented.
49. Technologies, feasibility, and management strategies for on-board multi-source energy networks
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Ahmed, Sanjana, Castellazzi, Alberto, Williams, Arthur, Ahmed, Sanjana, Castellazzi, Alberto, and Williams, Arthur
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The paper discusses the feasibility of installing renewable energy generation technologies on sea-going transport, taking into account the additional weight and power consumption. This study in based on the power management of a 26,198 tonne commercial chemical tanker. The management system would aim at reducing the number of generators as well as the power required from burning fossil fuels. After a process of elimination of potential technologies based on feasibility of the project and shipboard application, the work is focused towards photovoltaic and wind energy generation in combination with fossil fueled engines and Li-ion battery storage covering the higher energy density needs, and the intermittent nature of renewables. The network architecture is optimized in order to have the highest efficiency, and reduced system weight. The results show that successful management of the system can lead to reduction in generator requirement, as well as fuel consumption and energy despite the weight of the extra installation.
50. Multi-source energy networks for cargo vessels
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Ahmed, Sanjana, Castellazzi, Alberto, Williams, Arthur, Ahmed, Sanjana, Castellazzi, Alberto, and Williams, Arthur
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The paper discusses the feasibility of installing renewable energy generation technologies on sea-going transport, taking into account the additional weight and power consumption. This study in based on the power management of a 26,198 tonne commercial chemical tanker. The management system would aim at reducing the number of generators as well as the power required from burning fossil fuels. After a process of elimination of potential technologies based on feasibility of the project and shipboard application, the work is focused towards photovoltaic and wind energy generation in combination with fossil fueled engines and Li-ion battery storage covering the higher energy density needs, and the intermittent nature of renewables. The network architecture is optimized in order to have the highest efficiency, and reduced system weight. The results show that successful management of the system can lead to reduction in generator requirement, and energy despite the weight of extra installations of photovoltaic and wind energy generation systems. By reducing the number of generators and allowing each remaining one to operate near their maximum power, the specific fuel consumption is improved, the efficiency is increased, resulting in significant fuel and cost saving, along with the mass of fuel to be carried on-board.
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