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The level of difficulty in designing electro-technique devices has increased, owing to thermal stress. With the development of electric vehicles and electric aircraft, and to keep up with the recent trend to create smaller electronic devices with reduced weight and increased efficiency, designers lean on improved thermal analysis systems or tools.
Thermal analysis shows the impact of power supply on heat generation and its effect on an electronic device's different components. In most cases, the efficiency of electronic devices depends upon increased power supply, so the designers need to continually analyze the heat generation and find ways to dissipate the device's heat.
Electronic devices comprise electrical circuits consisting of various components. These electronic components can be divided into two categories, namely, passive components and active components. Active components can change, add or lessen the gain of input energy. However, active components depend on passive components for their proper functioning.
In electronic circuits, heat is produced due to a gain in energy provided by active electronic components. This heat can harm the circuits and cause permanent damage to the device. Owing to this, the selection of electronic components is essential while designing a device.
To increase the reliability of a device, the prediction of its electronic components' possible thermal behavior is essential. Several methods are based on tedious mathematics and formulations that can predict thermal images of electronic components. In general, any electronic system's thermal design is derived from thermal parameters followed by the system’s electronic components.
The main focus of thermal management is proper heat control. As stated above, heat could limit microchips and other electronic components' performance and, thereby, reduce the reliability of the device in terms of its longevity and cost.
The demand for accurate thermal analysis has increased in industrial sectors such as LED lighting. An improved thermal management system will ensure a good heat dissipation for electronic devices, leading to an increase in processing power and bringing about high compactness.
Electrical Engineering to Improve the Level of Electrical Safety
The main focus of electrical engineering lies in bringing about improvements in electrical safety and reliability. This involves more research and development in the following areas stated below:
- Arc flash assessment studies (Incident Energy Analysis to ensure compliance with NFPA 70E and NFPA 70 (NEC))
- Short Circuit Studies and complex circuit analysis
- An improved power system modeling that is involved with the generation, transmission, and distribution of energy
- Electrical hazardous area classification involving environmental and seismic qualification
- Technical solutions for electrical/electronic equipment obsolescence issues
- Fire probabilistic risk assessment and circuit analysis
- Evaluations of electrical system designs
- Testing for load flow
Techniques Used in Thermal Management
Various software helps in thermal analysis through models and computational fluid dynamics, allowing better management of airflow and temperature of components and various joints.
In the development of electronic devices, various tools are available for thermal management. For example, Electrical Transient Analyzer Program (ETAP) acts as a safety management program used to test load flow, short circuit, arc flash, motor starting, and other coordination studies. Similarly, SKM Systems Analysis Inc. is also involved in power system analysis and develops software for fault calculations, coordination, load flow, arc flash hazards, motor starting, grounding, harmonics, reliability, cable pulling, transient stability, and many comprehensive safety management programs.
Analytical Tools for Thermal Analysis of Electronic Components
Equivalent Thermal Circuit (ETC)
This is a conventional method for thermal analysis, which is based on equivalent circuit parameter studies. This method involves identifying the circuit and its heat flow system, followed by the determination of each component. Primarily, the equivalent thermal circuit splits the motor into different areas where temperatures are assumed to be constant.
Owing to this reduced number of nodes, evaluating the effect of power on the circuit becomes convenient. Energy transmitted from one point to another is, thereby, triggered by thermal resistance. The current in each resistance correlates to the heat power transferred from one node to another node. In this system, temperature estimates in each node correspond to steady states. This system also allows the addition of capacitances to measure transient thermal profiles.
Finite Element Analysis (FEA)
The study of conduction in solid bodies uses finite element tools such as Flux 2D/3D software. This software's main benefit is that it provides a better understanding of the heat exchange inside the motor. Another advantage of Flux is that its operation time is minimum and is user-friendly.
Cadence, a computational software company, has designed a single instrument for a complete thermal evaluation. Its system is based on the combination of FEA techniques for solid structures and computational fluid dynamics (CFD) for fluids.
CT Kao, product management director in the Multi-Domain System Analysis Business Unit at Cadence, stated that the electrical performance depends on the accuracy of thermal profiling. He said that it is important to consider several parameters simultaneously, such as power leakage and electrical resistance, for a better design.
Celsius Thermal Solver performs static (stationary) and dynamic (transient) electrothermal simulations based on the actual flow of electrical energy in advanced 3D structures and provides maximum visibility on the behavior of the real system. Cadence announced that its Celsius Thermal Solver is the first complete electric-thermal co-simulation solution for the entire range of electronic systems, from integrated circuits to physical containers.
References and Future Readings
Emilio, M.D.P. (2019). Thermal Analysis for Power Devices. [Online] Available at: https://www.eetimes.com/thermal-analysis-for-power-devices/
Marche, V. (2018). Thermal Analysis of Electrical Equipment - Different Methods Review. Altair HyperWorks Insider. [Online] Available at: https://insider.altairhyperworks.com/thermal-analysis-of-electrical-equipment-different-methods-review/
Thermal Analysis of Electronic Components (or, is it Electrical)? Fauske Team, LLC. 2018. [Online] Available at: https://www.fauske.com/blog/thermal-analysis-of-electronic-components-or-is-it-electrical
Akole, S.S. and Kulkarni, V.B. (2016). Thermal Analysis of Active Electronic Component with Thermal Imaging. ICTCS '16: Proceedings of the Second International Conference on Information and Communication Technology for Competitive Strategie, 37, pp. 1-6. DOI: 10.1145/2905055.2905095
Cadence.com, (2019). Celsius Thermal Solver. [Online] Available at: https://www.cadence.com/content/dam/cadence-www/global/en_US/documents/tools/system-analysis/celsius-thermal-ds.pdf [Accessed 9 Mar. 2021].
Skm.com, (2021). SKM’s Official Website. [Online] Available at: https://www.skm.com/ [Accessed 9 Mar. 2021].
Etap.com, (2021). ETAP’s Official Website. [Online] Available at: https://etap.com/ [Accessed 9 Mar. 2021].