Thermal Analysis of High Efficiency High Speed Drives

2019 ◽  
Author(s):  
Yasmin Khakpour ◽  
Weilun Warren Chen ◽  
Parikshith Channegowda ◽  
Matthew R. Pearson ◽  
Yongduk Lee ◽  
...  
Keyword(s):  
Thermal Analysis ◽  
Thermal Resistance ◽  
Power Electronics ◽  
Thermal Management ◽  
High Speed ◽  
High Efficiency ◽  
Management Strategies ◽  
Substantial Reduction ◽  
Operating Conditions ◽  
Heat Conducting

Abstract The thermal management of the PCB based power electronics is a key element to ensure safe operating conditions and to meet lifetime, reliability and safety requirements. This is challenging for applications above 1 kW because the substrate material used in a PCB such as FR-4 has very low heat conducting properties. Hence, there is a limit on how much loss can be dissipated from the board and for that reason this approach has only been adopted in the industry for very low power applications. With the proposed multilevel topology, WBG devices, and innovative thermal management strategies it is possible to expand the PCB based power electronics approach to power ratings between 1kW and 10 kW. For instance, an improvement in the thermal resistance of the PCB can be obtained by soldering a discrete WBG device with a TO-263 package directly on a PCB with about one inch square copper area around the device which will act as a heat spreader. Then, a further substantial reduction in the thermal resistance of a PCB is possible by the application of electrical vias. In principle each via is a copper sleeve through the board or through a part of the board. Where, instead of using its electrical function, a via can also be used as a thermal conductor. In this work, the thermal analysis of the PCB and the effect of number of vias as well as the effect of filling the vias with a thermally conductive material has been studied. The design has been optimized for the number of vias and the modeling results have been verified with experimental tests.

Operating Conditions and System Considerations for a Reversible Solid Oxide Cell System for Electrical Energy Storage

2014 ◽  
Author(s):  
Christopher H. Wendel ◽  
Pejman Kazempoor ◽  
Robert J. Braun
Keyword(s):  
Energy Storage ◽  
Thermal Management ◽  
Management Strategies ◽  
Electrical Energy ◽  
Cell System ◽  
Operating Conditions ◽  
Solid Oxide ◽  
System Level ◽  
Widespread Application ◽  
Electrical Energy Storage

Electrical energy storage (EES) is an important component of the future electric grid. Given that no other widely available technology meets all the EES requirements, reversible (or regenerative) solid oxide cells (ReSOCs) working in both fuel cell (power producing) and electrolysis (fuel producing) modes are envisioned as a technology capable of providing highly efficient and cost-effective EES. However, there are still many challenges from cell materials development to system level operation of ReSOCs that should be addressed before widespread application. One particular challenge of this novel system is establishing effective thermal management strategies to maintain the high conversion efficiency of the ReSOC. The system presented in this paper employs a thermal management strategy of promoting exothermic methanation in the ReSOC stack to offset the endothermic electrolysis reactions during charging mode (fuel producing) while also enhancing the energy density of the stored gases. Modeling and parametric analysis of an energy storage concept is performed using a thermodynamic system model coupled with a physically based ReSOC stack model. Results indicate that roundtrip efficiencies greater than 70% can be achieved at intermediate stack temperature (∼680°C) and pressure (∼20 bar). The optimal operating conditions result from a tradeoff between high stack efficiency and high parasitic balance of plant power.

A Bladeless Turbocompressor Concept: Shear Driven Gas Compression With Deformable Structures: Part 2 — Operating Principles and Theory

2017 ◽  
Author(s):  
Hooshang Heshmat ◽  
José Luis Córdova
Keyword(s):  
Shear Flow ◽  
High Speed ◽  
High Efficiency ◽  
Plate Theory ◽  
Operating Conditions ◽  
Fluid Film ◽  
Specific Power ◽  
Compliant Surface ◽  
Gas Compression ◽  
Smooth Disk

The theory underlying a novel method of gas compression driven by shear flow for next generation turbo-machinery is presented. The concept is based on the conversion of shaft power into hydrodynamic pressure and fluid flow that occur in the shear flow between a smooth rotating disk and a compliant surface counterface. This also holds for the inverse process, where gas expansion through the gap between the compliant surface and a shaft-mounted disk converts gas pressure into rotating power and torque. This is a logical evolutionary step that leverages the proven functionality of self-actuated fluid film compliant foil bearings and seals which operate in the hydrodynamic regime. Thus, as in these devices, the process of compression induced by shear flow is dominated by the balance between pressure and viscous forces which are in turn enhanced and controlled by tribological effects arising between the fluid film and the geometry of the counterface compliant surface. A model based on the compressible Reynolds equation coupled to the thin-plate theory formulation for compliant foil deflection is presented and parametrically solved to predict pressure, flow rate, and shear losses. The smooth disk and four-pad (sectored) compliant counterface effective size (7.6 mm < r < 14.1 mm), disk operating speed (50,000 to 360,000 rpm), nominal initial gap (0.03 mm < h0 < 0.635 mm), and overall operating conditions chosen for the parametric study correspond to those envisioned for eventual practical integration of miniaturized external combustion bladeless gas turbine engines and turbocompressors. Theoretical performance curves reporting flow versus pressure as well as compression power requirements versus speed were obtained. The predictions of the analysis are compared to results obtained experimentally on a proof of concept engine and presented in a companion paper. The simplicity of the bladeless geometry makes it amenable to deployment in multistage configurations, so that in conjunction with its foil bearing predecessors, this novel technology will result in low cost, ultra-high speed, high specific power and power density, high efficiency, oil-free and maintenance-free engines — attractive for many practical applications, ranging from military micro-UAV propulsion and portable power systems, to domestic combined heat and power turboalternators, and even micro-compressors for portable medical devices. As a point of reference, it is anticipated that a 10-stage bladeless compressor based on a compression stage as described herein would have a size comparable to that of a 355 mL soda can delivering a flow of 1 kg/min of compressed air.

scholarly journals Electric-Drive Vehicle Power Electronics Thermal Management: Current Status, Challenges, and Future Directions

2021 ◽  
Author(s):  
Gilberto Moreno ◽  
Sreekant Narumanchi ◽  
Xuhui Feng ◽  
Paul Anschel ◽  
Steve Myers ◽  
...  
Keyword(s):  
Thermal Resistance ◽  
Power Electronics ◽  
Thermal Management ◽  
Power Density ◽  
Thermal Performance ◽  
Electric Drive ◽  
Thermal Analyses ◽  
Heat Fluxes ◽  
Current Status ◽  
Dielectric Fluid

Abstract Effective thermal management of traction-drive power electronics is critical to the advancement of electric-drive vehicles and is necessary for increasing power density and improving reliability. Replacing traditional silicon devices with more efficient, higher temperature, higher voltage, and higher frequency wide-bandgap (WBG) devices will enable increased power density but will result in higher device heat fluxes. Compact packaging of high-temperature WBG devices near low-temperature-rated components creates thermal management challenges that need to be addressed for future power-dense systems. This paper summarizes the thermal performance of on-road automotive power electronics thermal management systems and provides thermal performance and pumping-power metrics for select vehicles. Thermal analyses reveal that the package/conduction resistance dominates the total thermal resistance (for existing automotive systems). We model advanced packaging concepts and compare the results with existing packaging designs to quantify their thermal performance enhancements. Double-side-cooled configurations that do not use thermal interface materials are package concepts predicted to provide a low junction-to-fluid thermal resistance (compared to current packages). Dielectric-fluid-cooled concepts enable a redesign of the package to reduce the package resistance, can be implemented in single- and two-phase cooling approaches, and allow for cooling of passive components (e.g., capacitors) and bus bars.

Using ESP Permanent Magnet Motor Technology in High-Temperature Geothermal Applications

2021 ◽  
Author(s):  
Natalia Lykova ◽  
Danila Martiushev
Keyword(s):  
High Temperature ◽  
Permanent Magnet ◽  
High Speed ◽  
Power Plants ◽  
High Efficiency ◽  
Induction Motors ◽  
Renewable Energy Sources ◽  
Hot Water ◽  
Heat Conducting ◽  
Permanent Magnet Motor

Abstract Geothermal energy is one of the more efficient renewable energy sources. It uses heat from the Earth's interior to produce electricity in geothermal power plants. In binary cycle power plants, geothermal water can often be produced naturally from high-pressure wells. But when reservoir pressure drops, these power plants need to add artificial lift to continue to produce needed quantities of hot water. The geothermal industry is looking at electrical submersible pumping (ESP) systems as a way to improve geothermal fluid production. But ESPs were designed for the conditions in oil wells and are subject to severe complicating factors in geothermal conditions that significantly reduce runlife, such as temperatures up to 200°C (390°F), highly corrosive fluid, and salt deposition (scale). At the same time, production rates need to be higher than those typical of oil production. The most commonly used geothermal pumps are driven by a transmission shaft and drive on the surface, or they use a submersible asynchronous induction motor. Surface-driven pumps, commonly called line-shaft pumps, have significant depth limitations. Submersible asynchronous induction motors cannot provide a sufficient volume of fluid supply and tend to overheat in high-temperature conditions. To compensate for the heat, induction motors must operate underloaded. Even so, they are subject to frequent premature failures with operating times of between 30 and 100 days. To solve the problem of cost-effective exploitation of geothermal fields, Novomet used its expertise with permanent magnet motors and high-speed pumps to develop an electrical submersible pumping system that would offer more reliability and runlife in geothermal conditions. A 254-mm (10-in.) geothermal submersible pumping (GSP) system was designed, manufactured, and tested with a production output of up to 12,000 m3/d (75,477 bbl/d, 139 l/s, 2201 gpm,). It featured new generation, high-efficiency pump stages and a permanent magnet motor with a capacity of up to 1.5 MW. The GSP system design was field tested in Turkey. Improvements to early system designs include the use of a heat-conducting filler in the materials used to compound the permanent magnet motor, the adoption of various high-temperature-rated components (AFLAS rubber elements, RYTON motor terminals, and heat-resistant motor oil), and the development of metal-to-metal sealing in the motor lead extension. One of the early GSP systems installed in the field performed reliably for 470 days at a frequency of 90 Hz, significantly exceeding the target runtime. More than thirty units with a total flow rate of 190,000 m3/d (1,195,000 bbl/d, 2199 l/s, 34,856 gpm) are currently in operation in Turkey. The electrical consumption savings average 25% for each GSP system with a permanent magnet motor compared to systems using asynchronous induction motors. While designed for geothermal applications, GSPs can also be used in oil and gas operations.

Temperature Distribution in Advanced Power Electronics Systems and the Effect of Phase Change Materials on Temperature Suppression During Power Pulses

2000 ◽  
Vol 123 (3) ◽  
pp. 211-217 ◽  
Author(s):  
A. G. Evans ◽  
M. Y. He ◽  
J. W. Hutchinson ◽  
M. Shaw
Keyword(s):  
Thermal Analysis ◽  
Phase Change ◽  
Power Electronics ◽  
Phase Change Materials ◽  
Power Input ◽  
Operating Conditions ◽  
Junction Temperature ◽  
Package Design ◽  
Materials Used

A thermal analysis has been performed for a package design pertinent to power electronics. The objective has been the derivation of straightforward expressions that relate the materials used and their physical dimensions to the power input and the junction temperature. This has been done for both steady-state operating conditions and for pulses. The role of phase change materials (PCMs) in suppressing temperature elevations during pulses is also addressed.

Advanced Cooling of 3D ICs With Nanoparticle Packings

2017 ◽  
Author(s):  
Anil Yuksel ◽  
Paul S. Ho ◽  
Jayathi Murthy
Keyword(s):  
Thermal Resistance ◽  
Thermal Management ◽  
Heat Dissipation ◽  
Management Strategies ◽  
Liquid Cooling ◽  
The Third ◽  
3D Ics ◽  
Solution Methods ◽  
Surface Phonon Polariton ◽  
Third Dimension

Thermal-aware techniques for 3D ICs have shown that high temperatures dramatically reduce the lifetime and the reliability of the 3D ICs with utilizing the third dimension. Hence, thermal management has been very crucial for the further improvement of the 3D IC architecture. There has been some thermal management strategies suggested at the micro/nano scale to alleviate the nonlocal heat dissipation; however, many solution methods such as liquid cooling have challenges and create many problems. In this paper, we propose nanoparticle based interfacial cooling to improve the thermal transport due to surface phonon polariton coupling and to reduce the thermal resistance between the interfaces. We demonstrate the efficiency of the heat dissipation from the proposed structure for 3D ICs.

Experimental Study on the Double-Sided Air Cooling for Integrated Power Electronics Modules

2005 ◽  
Author(s):  
Ying Feng Pang ◽  
Elaine P. Scott ◽  
Zhenxian Liang ◽  
J. D. van Wyk
Keyword(s):  
Thermal Resistance ◽  
Power Electronics ◽  
Thermal Management ◽  
Heat Sink ◽  
Three Dimensional ◽  
Management Approach ◽  
Air Cooling ◽  
Thermal Tests ◽  
Heat Spreaders ◽  
Embedded Power

The objective of this work is to quantify the advantages of using double-sided cooling as the thermal management approach for the integrated power electronics modules. To study the potential advantage of the Embedded Power packaging method for the double-sided cooling, experiments were conducted. Three different cases were studied. To eliminate the effect of the heat sink on either side of the module, no heat sink was used in all three cases. The thermal tests were conducted such that the integrated power electronics modules were placed in the middle of flowing air in an insulated wind tunnel. Modules without additional top DBC, with additional top DBC, and with additional top DBC as well as heat spreaders on both sides were tested under the same condition. A common parameter, junction-to-ambient thermal resistance, was used to compare the thermal performance of these three cases. Despite the shortcoming of this parameter in describing the three-dimensional heat flow within the integrated power electronics modules, the concept of the thermal resistance is still worthwhile for evaluating various cooling methods for the module. The results show that increasing the top surface area can help in transferring the heat from the heat source to the ambient through the top side of the module. Consequently, the ability to handle higher power loss can also be increased. In summary, the Embedded Power technology provides an opportunity for implementing double-sided cooling as thermal management approach compared to modules with wire-bonded interconnects for the multichips.

scholarly journals Efficient lubrication of a high-speed electromechanical powertrain with holistic thermal management

2020 ◽  
Author(s):  
B. Morhard ◽  
D. Schweigert ◽  
M. Mileti ◽  
M. Sedlmair ◽  
T. Lohner ◽  
...  
Keyword(s):  
Thermal Management ◽  
High Speed ◽  
High Efficiency ◽  
Electrical Machine ◽  
Lubrication System ◽  
Joint Research ◽  
Oil Distribution ◽  
Joint Research Project ◽  
Oil Flow ◽  
Dynamics Simulations

Abstract In order to increase the power density of BEVs (Battery Electric Vehicles), high-speed concepts are being progressively developed. With increased speed, the power of the electrical machine can be maintained with reduced torque and therefore size, resulting in cost and package advantages. In the joint research project Speed4E with seven industrial and five university partners, such high-speed electromechanical powertrain is being developed and investigated. The electrical machines will run at a maximum rotational speed of 50,000 rpm in the test rig and 30,000 rpm in the test vehicle. The developed lubrication system for the Speed4E transmission aims for high efficiency and optimized heat balance, via a demand-oriented oil flow. In this context, this study investigates how an efficient lubrication system can be designed with respect to the holistic thermal management of the vehicle. Therefore, a hybrid lubrication consisting of dip and injection lubrication is realized. For the analysis and evaluation, efficiency calculations and CFD (Computational Fluid Dynamics) simulations of the oil distribution are presented.

Evaluation of Combined Active and Passive Thermal Management Strategies for Lithium-Ion Batteries

2016 ◽  
Vol 13 (3) ◽  
Author(s):  
Carlos F. Lopez ◽  
Judith A. Jeevarajan ◽  
Partha P. Mukherjee
Keyword(s):  
Phase Change ◽  
Lithium Ion Batteries ◽  
Phase Change Material ◽  
Thermal Management ◽  
Management Strategies ◽  
Lithium Ion ◽  
Operating Conditions ◽  
Management Systems ◽  
Trade Offs ◽  
Change Material

Lithium-ion batteries are the most commonly used portable energy storage technology due to their relatively high specific energy and power but face thermal issues that raise safety concerns, particularly in automotive and aerospace applications. In these environments, there is zero tolerance for catastrophic failures such as fire or cell rupture, making thermal management a strict requirement to mitigate thermal runaway potential. The optimum configurations for such thermal management systems are dependent on both the thermo-electrochemical properties of the batteries and operating conditions/engineering constraints. The aim of this study is to determine the effect of various combined active (liquid heat exchanger) and passive (phase-change material) thermal management techniques on cell temperatures and thermal balancing. The cell configuration and volume/weight constraints have important roles in optimizing the thermal management technique, particularly when utilizing both active and passive systems together. A computational modeling study including conjugate heat transfer and fluid dynamics coupled with thermo-electrochemical dynamics is performed to investigate design trade-offs in lithium-ion battery thermal management strategies. It was found that phase-change material properties and cell spacing have a significant effect on the maximum and gradient of temperature in a module cooled by combined active and passive thermal management systems.

Flat Heat Pipe Cooling Devices for Mobile Computers

2003 ◽  
Author(s):  
Yaxiong Wang ◽  
G. P. Peterson
Keyword(s):  
Thermal Resistance ◽  
Heat Pipe ◽  
Thermal Management ◽  
High Efficiency ◽  
Junction Temperature ◽  
Working Fluid ◽  
Closed Chamber ◽  
Maximum Heat ◽  
Micro Heat Pipe ◽  
Mobile Computers

The rapid increases in package density in the high-performance microprocessors utilized in laptop, notebook and other mobile computers has resulted in power-densities that are challenging the existing thermal management technologies. In order to accomodate these challenges within the existing space and volume constraints, a novel, flat, micro heat pipe (MHP) cooling device has been conceptualized, designed, and evaluated analytically. The novel device consists of a flat micro heat pipe heat spreader, fabricated by sintering copper mesh and wires between two thin copper sheets to form a closed chamber. High-efficiency folded fins are then bonded to the condenser to produce a device that is capable of dissipating the high heat loads and reducing the thermal resistance typically present in these packages. Because of its high latent heat and surface tension, water was used as the working fluid. A number of different designs with different CPU mounting positions and fin sets were examined theoretically in an effort to optimize the initial design. The effects of the physical properties of the mesh, wire diameter, and effective thermal conductivity of the capillary structure were then evaluated and optimized. This process resulted in a design optimized on thermal performance, that is an excellent candidate for the thermal management of laptop and/or notebook computers. At a junction temperature of 85 °C, the maximum heat transport capacity and corresponding thermal resistance of an optimized MHP heat sink, 25.4 man wide and 152.4 mm long, were 33 W and 0.80 W/°C, respectively, for an environmental temperature of 45 °C.

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