Cost, energy efficiency and reliability are the key factors for widespread usage of microgrids
in developing sustainable green buildings and communities. Minimum energy conversion stages
with high energy efficiency are required in order to achieve this goal. Silicon Carbide (SiC) and
Gallium Nitride (GaN) power switching devices with superior electrical and thermal
performances than silicon promise significant energy and cost savings for power electronics
converters. However, special care must be taken in circuit design, system integration and
packaging of SiC and GaN power converters for reliable operation at increased switching
frequencies and elevated temperatures.
This half-day short course will present an overview and performance advantages of
commercial state-of-the-art SiC and GaN power switching devices. Prototype converter designs
will be discussed with experimental data to demonstrate significant efficiency gains in lowvoltage
point-of-load (PoL) power converters, DC-DC converters and inverters. A tradeoff in
performance vs. cost will be made at the system level.
- Device structures
- Data sheets
- Key performance and reliability parameters
- Power diodes
- Power MOSFETs
- Gate drive requirements
- Dead-time management
- Layout techniques for high-frequency, multi-megahertz switching
- Paralleling techniques for higher current
- Thermal design considerations
- PoL GaN power converter
- SiC power inverter
Krishna Shenai is Distinguished Professor and Director of R&D at NMAM Institute of
Technology, Nitte, Karnataka. Dr. Shenai received his B. Tech. degree in electronics from IITMadras
in 1979, and MS and Ph.D. degrees in electrical engineering from The University of
Maryland and Stanford University in 1981 and 1986, respectively. For more than 35 years, Dr.
Shenai has pioneered and made seminal contributions to power semiconductor devices and
power electronics converters. He is a Fellow of IEEE, a Fellow of the American Physical
Society, and a Fellow of the American Association for the Advancement of Science. Dr. Shenai
has authored over 450 peer-reviewed papers and 10 book chapters, edited 4 books and 10
conference digests, and holds 13 issued US patents. He is an Editor of IEEE J. Electron Device
The AC Vs DC debate between Tesla and Edison was over in late 19th century,
with transformer technology enabling AC power-distribution lines to have a distinct advantage.
World-over, expansion of AC power-lines happened, with DC lines virtually dying slowly but surely.
R&D and manufacturing focused on protection and power-distribution of AC power-lines and work on DC
power-line all but vanished. AC appliances proliferated the market.
When the DC power was almost forgotten, it took a back-door entry into homes and offices in 1970s.
The advent of Integrated Circuits made electronic systems and devices reliable,
inexpensive and usable by people at large. These electronic systems however needed DC power and
AC-DC converters came along with all such electronic systems. These converters had losses and were
less reliable than the electronic systems itself. But the electronics systems consumed low-power
and some losses in the converters were acceptable. But as electronics started dominating homes
and offices (TVs, radios, music systems, cell-phones, tablets, personal computers, laptops, displays
and almost every sensor) the sum-total of the losses became considerable.
Then a few years back, LED emerged as energy-efficient lighting source. Now these LEDs needed DC
power, requiring AC to DC converters when powered on AC power lines. Again these converters had losses.
At around the same time, Power electronics, which used discreet devices earlier, got a big boost with
the emergence of Power-electronics Integrated Circuits. Now complex power-electronics circuits could
be designed and manufactured at much lower-costs. This impacted converter design, but probably far
more significantly, the design of Motors. Brushless DC (BLDC) motors and Switch Reluctance (SR) motors
became inexpensive when manufactured in volumes and could now compete with the cost of AC induction
motors. Now the BLDC motors and SR motors were far more energy-efficient as compared to AC induction
motors, especially at variable speed. Further, they needed DC power and the power form AC line needed
to be converted to DC to power them. BLDC motors and SR motors started appearing in fans, refrigerators,
air-conditioners, mixers and grinders, washing machines, chillers, lifts and pumps, simply because they
made it far-more energy-efficient.
Soon it came into being that almost all appliances used at homes and offices had become DC.
Power from AC line needed to be converted to DC to power each of them. What if a DC power-line was
available at homes and offices? While the question was still in the minds, the final blow came
from roof-top solar PV systems and batteries. The former generated only DC power and the later
was charged and outputs DC power. Again converters (also referred to as inverters) would be required
to connect them to AC power-lines at homes and offices. It was pretty clear that an alternative was
needed. DC micro-grids for homes and offices was staring at us.
1. Moving from AC power-line to DC power line at homes/offices: why? What difference does solar mean?
a. What are the gains?
b. Are we ready?
c. What voltages are suitable and why: choices and reasons for selection
2. Appliances with equipment: what is available and what is needed
3. Connecting homes to solar DC – architecture, technological challenges and economics
4. Solar DC solution for commercial buildings and complexes: architecture,technological challenges and economics
5. Solar DC for Agriculture
Dr. Ashok Jhunjhunwala is Professor at the Department of Electrical Engineering,
Indian Institute of Technology Madras India. He received a B.Tech degree from IIT, Kanpur,
and M.S. and Ph.D degrees from the University of Maine, USA. He has been a member of the faculty at IIT,
Madras since 1981 and Department Chair until recently. Professor Jhunjhunwala has the unique
distinction among academics for combining innovations in technology and business incubation with the
social goal of sustainable development in India.
He is considered the pioneer in nurturing Industry-Academia interaction in India towards R&D,
Innovation and Product Development. He conceived and built the first Research Park (IIT Madras Research
Park) in India which houses over 100 R&D companies in its 1.2 million square feet built-up area. Having
made a mark in telecom, over the last couple of years he has focused on power and has come up with
innovation to ensure that all homes in India get 24x7 power even in situation of extreme power-shortage.
The following papers have been accepted for oral paper presentations at the SGBC Conference
The following papers have been accepted for Poster sessions at the SGBC Conference
All Authors will receive an email from the organising team before 23 September 2016.