Esgee Technologies will be presenting at this year’s Society of Automotive Engineers (SAE) WCX World Congress Experience held in Detroit, Michigan from April 5th to 7th. Our paper, “Modeling of Switching Characteristics of Hydrogen-Nitrogen Filled DC Contactor Under External Magnetic Field,” was chosen from hundreds of submissions to be featured at the event.
WCX is among the top annual gatherings which provides an intersectional forum between automotive engineers, researchers, scientists, and technical innovators. This year’s topics include EV technology and electrical infrastructure, energy storage and battery disposition, as well as design and safety for automated vehicles.
We sat down with Dr. Rakesh Ranjan, who will be presenting on behalf of EsgeeTech this year, in order to learn more about the applications for this research and how they align with the conference’s goals:
What applications are there for EV relay arcs? And why choose SAE to discuss them?
SAE is the biggest confluence of engineers dedicated to enhancing our mobility in an environmentally friendly manner. If you are excited about the prospect of buying a cleaner vehicle which won’t contribute to environmental pollution, it’s likely that the EV technologies behind it started as concepts presented at an SAE conference. Technologies for the future of mobility have their beginnings right here at SAE conferences.
As for EV relays, it is a critical component for the safety of electric vehicles. With increasing power needs for electric vehicles, there comes an increase in things like battery size and voltage levels required to drive vehicles. An increase in voltage means that electric isolation of safety-critical components would be delayed due to prolonged arcing. So, how safe your vehicle is could ultimately depend on how quickly the arc channel inside the EV relay quenches.
Perhaps it may not be the first feature that consumers think of when it comes to vehicle safety, but for manufacturers and anyone involved in future maintenance on the vehicle, arc-resistant equipment is key to creating a safe environment. For the owner of an electric vehicle, arc-quenching is also a means of decreasing or completely removing the risk of damage from arc flash events. That, of course, is desirable because it means lowered maintenance costs and higher longevity for critical automotive components.
What is the quick takeaway from your talk?
A one-minute synopsis of my talk would be about the use of hydrogen-nitrogen mixtures for quenching of arcs. One typically associates hydrogen with flammability, but it also has fantastically high diffusive properties which could lead to quicker arc quenching. We report how hydrogen concentration leads to smaller arc lifetimes, which in turn improves a circuit’s interruption performance. We simulated contact separation in hydrogen-enriched and pure air environments using VizSpark™ which showed us that a strong external magnetic field can stretch the arc and reduce its extinction time.
You mention that you used VizSpark™ in your research. Why choose VizSpark™ specifically? What scenarios / applications is it useful for?
VizSpark™ is a multiphysics CFD solver which is capable of capturing the interaction between the plasma and flow with high fidelity. One thing which I really like about it is its robustness for a wide range of thermal plasma problems. You can throw in tough multiphysics problems: permanent magnets, high voltages and currents, supersonic flows, conjugate heat transfer. In terms of industrial applications, I could think of EV Relays, fuses, and high-voltage circuit breakers. It could also be used for safety assessment in high-voltage applications. For example, if there is local arcing inside a battery pack and you want to assess the root-cause through V-I traces, you could potentially do it in VizSpark™.
WCX ’22 Attendees can view Dr. Ranjan’s presentation in the “Electric Motor & Power Electronics” session from 10:00 AM to 10:30 AM CDT on Wednesday, April 6th.
Thanks for reading! If you’re still curious about the topics discussed in this article, check out the following journal papers (and ask us for a free copy!):
Ranjan, Rakesh, et al. Modelling of switching characteristics of hydrogen-nitrogen filled DC contactor under external magnetic field. No. 2022-01-0728. SAE Technical Paper, 2022.
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We are pleased to announce that the latest version of the OverViz software package has been released! Our latest version of industry leading plasma-fluid-electromagnetic-particle simulation software follows up on our previous v2.4.0 release with bug fixes, improvements to the GUI and two new particle examples.
Key New Features and Enhancements
• Improvements to the VizGlow GUI and fixes to flow, electromagnetics and particle panels
• Speed improvements to the VizEM electromagnetics module (up to 2x speed for some examples)
• New Example: RF Gridded Xenon Ion Thruster
• New Example: Particle-in-Cell GEC Reference Cell Validation
New installers and installation instructions are available for download from the Esgee Corporate Portal. Please contact us if you have any questions, need help accessing the Portal, or are interested in learning more about v2.4.1
We are pleased to announce that the latest version of the OverViz software package has been released! Many new additions and enhancements have been made to our flagship VizGlow non-thermal and VizSpark thermal plasma solvers.
Key New Features and Enhancements
• New improved VizMesh with improved usability, bug fixes, capability to add splines to geometry, specify primitive shapes as modular objects, import STL files.
• New capability to specify surface chemistry using particles in VizGrain
• Coupled circuits module with current continuity equation system in VizSpark
• Added new circuits to simulate spark ignition, and to perform frequency power control
• New fast model to predict streamer breakdown in VizGlow
• Hybrid initialization for improved convergence of steady state flow
• Capability to split EM power into capacitive and inductive components in VizGlow
• Extended VizGlow’s non-linear magnetostatics capability to support 2D TM, 3D problems
• Included an option to match EM Power absorbed in sync with VizGlow’s external circuits
• Improved handling of large meshes (> 10 million cells) by reducing memory footprint
• Improved the accuracy and stability of coupled circuit solver in VizGlow
• Improved the robustness and speed of the reactive flow solver in VizSpark
• Improved accuracy of the flow solver allowing for accurate shock capturing
• Improvements to electron mobility and diffusion models for magnetized plasma
• Improvements to the VizGrain particle charge-exchange reaction models
• Added a direct linear solver option for electrostatic potential equation in VizGlow
• Improvements to immersed-gas interface boundary condition in VizSpark
Plasma sources capacitively driven at very high frequencies (VHF, e.g.
100MHz) have attracted much interest for semiconductor device fabrication.
These sources have the advantage of high efficiency plasma generation since
power couples efficiently with electrons and with lower ion energy loss
through sheath acceleration. This is beneficial for processes requiring
reduced ion energy, high ion and radical flux. At the same time, spatial
variations in plasma density and sheath voltage can arise leading to
non-uniformities at the wafer. The root cause of VHF plasma non-uniformity
is related to both electromagnetic wave and sheath coupling effects.
Unfortunately, most previous plasma fluid models that include
electromagnetic wave effects have found it challenging to simulate this
physics. Predictive models that can capture these effects are important for
plasma properties and their uniformity in industrial systems. We have
recently developed approaches that have succeeded in reproducing how VHF
power influences plasma uniformity by hybridizing electrostatic and
electromagnetic power delivery in a plasma fluid model with no loss of
self-consistency. These simulations also demonstrate how low frequency added
to VHF impacts uniformity through a sheath-wave interaction mechanism.
Accurate predictions of the Ion Energy and Angular Distributions (IEADFs), are essential for a range of critical applications in thin films deposition and etching. Ion generation and flux is determined by ionization rates that depend on reactor-level parameters. Ion energy and angle depends on the acceleration of the ions across the sheath, driven by potential differences governed by the spatial plasma distribution. The IEADF at the wafer surface sensitively depends on rare collisional events such as charge exchange and ion-neutral collisions during the ion’s transit across the sheath. Using ion transport parameters computed using standard fluid modeling techniques can significantly misrepresent the actual IEADFs at surfaces. In this study we use a hybrid approach where we employ VizGlow, a fluid based plasma solver, to simulate a (pulsed) Inductively Coupled Plasma (ICP) source with a (pulsed) RF bias. Then we use VizGrain, a companion particle solver, to compute the IEADFs using the test-particle approach. We study the effect of pressure, pulse width and duty cycle and the staggering of the source and bias pulsing cycles on the IEADFs using Argon plama. We compare the simulation results to measurements of IEADFs on a test plasma platform for validation purposes.