#2 Interview With L Umanand
Podcast ·Lalit and Abhijit interview their PhD advisor and mentor, Prof. L. Umanand of the Department of Electronic Systems Engineering at the Indian Institute of Science Bangalore (DESE, IISc).
Show Notes
- Guest Profile:
- Prof L Umanand, Department of Electronic Systems Engineering (DESE), Indian Institute of Science (IISc), Bangalore, India
- Personal webpage
- Undergraduate education: B.E. (Bachelor of Engineering)
- Electronics and communication engineering
- Using discrete, and then integrated devices, to build transmitters and receivers (ham radio)
- Fear of power electronics: SCR (Silicon Controlled Rectifier) waveforms
- Masters’ degree: M. Tech.
- Electronics Design and Technology, IISc, Bangalore
- Impact of a great teacher on getting attracted to power electronics: Prof Ramesh Bhat
- Areas of present interests: power conversion, DC/DC converters, DC/AC converters (inverters), renewable energy, photovoltaics (PV), motor drives, electric vehicles (EV)
- Typical power electronics course at DESE: 2 hours/week theory, >3 hours/week lab
- “It is difficult to draw a demarcation line between implementation and research. They are highly coupled, intermingled.”
- Masters’ students typically take up closed-form projects that are implementation-oriented and time bound.
- PhD (research) students typically take up open-ended problems where the end-time is not always fixed.
- Promoting interaction between masters and PhD students through overlap in projects.
- Solar desalination project by Dr. Ravinder Kumar
- Problem with earlier approach: Membrane-based desalination needs frequent replacement of membranes.
- Proposed solution: Increase flow rate of distilled water using two-stage distillation and pressure modulation to reduce boiling point of water.
- Modeling of thermal systems using bond graphs.
- Related publications:
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Ravinder Kumar and L. Umanand, “Dynamic pressure modulation for solar desalination system,” Desalination, vol. 249(1), pp. 90-98, 2009. URL: https://www.sciencedirect.com/science/article/abs/pii/S0011916409007528
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Ravinder Kumar and L. Umanand, “Modeling of a pressure modulated desalination system using bond graph methodology.” Applied Energy, vol. 86(9), pp. 1654-1666, 2009. URL: https://www.sciencedirect.com/science/article/abs/pii/S0306261909000282
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Two domains of knowledge:
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Physics: Dealing with the inanimate
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Life sciences: Dealing with the animate
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“If you look at physics as the mother of all the inanimates, you are domain-free, you lose the fear of domains. That is what an engineer should do.”
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Bond graphs vs block diagrams: Thinking in terms of energy transfer, effort variable, flow variable, input impedance, feedback effect, across multiple engineering domains.
- Introductory lecture on bond graphs by Prof Soumitro Banerjee, IIT Kharagpur https://www.youtube.com/watch?v=p9VZ3ONMqJs
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Solar cooking project by Dr. Prasanna UR
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Very low flow-rate meter
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Current control in the electrical domain transformed to mechanical domain using bond graphs.
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Related publications:
- UR Prasanna and L Umanand, “Non-disruptive and null-deflection mass flow measurement by a pressure compensation technique,” Flow Measurement and Instrumentation, vol. 21(1), pp. 54-61, 2010. URL: https://www.sciencedirect.com/science/article/abs/pii/S0955598609000557
- Prasanna U R and L Umanand, “Flow measurement system and a method thereof”, Indian patent application number: 2112/CHE/2009, August 2009.
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Big challenge for next few decades: Prime mover (or electric motor) design for e-mobility—cars, individual transport, 2/3/4 wheelers, locomotives.
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“Permanent magnet (PM) machines, such as the permanent magnet synchronous machine (PMSM), are not the solution. There is only one country which has monopoly on rare-earth PM materials.”
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Non-PM machines will gain importance: synchronous reluctance machines (SRM) with mechanical as well as virtual salient poles, electromagnetic synchronous machines using rotating transformers (non-contact, no slip rings, no brushes).
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Our systems will move more towards automation and robots.
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Energy storage:
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Li-ion batteries: popular technology today, high energy density and power density, but limited life.
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Ni-ion batteries: potential to form the backbone (large energy storage) for the electrical grid in presence of intermittent and distributed renewable energy sources. Long life of 15-20 years.
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Thermal power companies in India (e.g. NTPC) which are traditionally coal-based could soon be shifting to renewable energy (wind and PV) with large energy storage.
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- Advice to bachelors’ students in electrical and electronics engineering: “Focus on implementation. Understand the working of circuits, beyond just passing exams. They should be able to build interfaces. Basically electronics is nothing but building interfaces. On the left hand side, you have something, and on the right hand side, you have something [else]. In between them, you are building an electronic gadget to interface the left to the right. It could be analog, digital, signal, power…”
- “A PhD is a kind of meditation, a deep contemplation, it is not just a degree. The output of the PhD process is the mind of the person, the thesis is the vehicle, papers are spin-offs.”
- On publications: “Knowledge is for sharing. It is the only thing which increases within you when stolen. Publish your work in whatever way possible, the freer the better. Unfortunately, publications have become a number counting mechanism for career development.”
Additional information:
- Online Courses (NPTEL) by Prof L Umanand:
- Books by Prof L Umanand: