Engineering topics

Maharjan, Lizon

Publications and source records attributed to Maharjan, Lizon.

4 records

DOE OSTI2019

3D multiphysics simulation and analysis of a low temperature liquid metal magnetohydrodynamic power generator prototype

Magnetohydrodynamic (MHD) power generation is an interdisciplinary process, which was studied heavily in the late 1960’s but interest soon subsided. However, the current socioeconomic climate demands more diversity in renewable energy sources. MHD generators using liquid metal as the working fluid represent a viable option for this augmentation. Additionally, the steady increase in accessible computational capabilities provides a powerful new tool for interdisciplinary modeling and multiphysics simulations. These factors suggest that this is an opportune time to reevaluate MHD power generation. This paper provides mathematical background as well as a detailed multiphysics model of a low temperature liquid metal MHD power generator built in COMSOL. Simulation details are provided in addition to a comparison to experimental results. Finally, the prototype studied in this paper is the first proof of concept of a permanent magnet excited liquid metal MHD generator using Gallium as its working fluid.

24 POWER TRANSMISSION AND DISTRIBUTION↗

DOE OSTI2019

Structural Analysis of Induction Machine and Switched Reluctance Machine

Presented is a comprehensive analysis of structural performance of Induction Machine (IM) and Switched Reluctance Machine (SRM) rotors under different operational conditions. Electric machines are susceptible to forces of diverse origins. In addition to traditionally considered magnetic and centrifugal forces, this article discusses independent and inclusive effects of thermal expansion and shaft attachment techniques on structural integrity of the machines. A comparative analysis of structural performance of IMs and SRMs has also been performed, under a range of scenarios, to facilitate application specific machine selection from a structural perspective.

42 ENGINEERING↗

DOE OSTI2018

Machine learning based energy management system for grid disaster mitigation

The recent increase in infiltration of distributed resources has challenged the traditional operation of power systems. Simultaneously, devastating effects of recent natural disasters have questioned the resilience of power infrastructure for an electricity dependent community. In this study, a solution has been presented in the form of a resilient smart grid network which utilizes Distributed Energy Resources (DERs) and Machine Learning (ML) algorithms to improve the power availability during disastrous events. In addition to power electronics with load categorization features, the presented system utilizes ML tools to use the information from neighbouring units and external sources to make complicated logical decisions directed towards provide power to critical loads at all times. Furthermore, provided model encourages consideration of ML tools as a part of smart grid design process together with power electronics and controls, not as an additional feature.

24 POWER TRANSMISSION AND DISTRIBUTION↗

DOE OSTI2018

Comprehensive Report on Design and Development of a 100-kW DSSRM

Switched reluctance machines (SRMs) are low cost and fault tolerant alternatives for traction applications. Due to their relatively low torque density and high torque ripple, these machines have not been used in commercialized electrified power trains yet. The double-stator magnetic configuration, where a segmental rotor shared between two stators, is proven to have superior torque density, lower acoustic noise, and torque pulsation. The double-stator SRM (DSSRM) has a high potential of being the next generation of traction motors since it combines the advantages of permanent magnet-free machines, such as low cost and independence from supply chain issues associated with rare metals, while providing high torque and power densities. In this paper, we introduce the complete design process of a 100-kW DSSRM including electromagnetic, structural, thermal, and system level design. The performance of the developed DSSRM is verified with the experimental data. This paper presents overall study of DSSRM and describes merits of DSSRM drive system.

42 ENGINEERING↗