Tech Briefs Magazine - June 2023 - 12

Q & A
Intelligent Building Blocks for a More
Reliable Electric Grid
Dr. Radha Krishna
Moorthy is Lead Researcher
on an Oak
Ridge National Laboratory
project
to
create
a new architecture
to modernize the
electric grid from the
bottom up. The approach
combines hardware and software
to monitor equipment health, speed up
communication, and increase security.
Tech Briefs: Could you tell us something
about your system of building
blocks?
Radha Krishna Moorthy: The fundamental
building block is what we call
SUPER, which stands for smart universal
power electronic regulator. You can think
of it as either a DC/ DC system - an inverter
- or a DC/DC stage coupled to
a DC/AC stage. The block can take any
form or shape depending upon what sort
of power conversion you use. SUPERs in
turn have their own fundamental subcomponents.
For example, the power
stages that make up SUPER are called
IPS - intelligent power stages.
Tech Briefs: Can you tell me something
about the functions of the SUPER?
Krishna Moorthy: The basic function of
SUPER is power conversion say from AC to
DC or DC to DC. SUPER also hosts a variety
of special features from embedded intelligence
and decision making, to online
health monitoring, autonomous operation
capability, and cyber-physical security.
If you read reports from solar panel
installers or utility personnel, the biggest
potential failure points are capacitors
and the power semiconductor devices.
So, it would be really helpful if you could
add an additional layer of monitoring.
Tech Briefs: What kinds of measurements
would you take to measure the
health of the semiconductors?
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Krishna Moorthy: We measure the
on-state voltage of the semiconductor
device. And we have provisions to directly
measure the drain source. So, using
these two, I can compute the on-state
resistance, which could help me predict
the failure mechanism related to semiconductor
modules. And besides that,
there is data like base plate temperature,
junction temperature of the devices, capacitance
estimates, etc. We can accumulate
this data at an upper layer to give us
information about the system health.
Tech Briefs: What sort of power ratings
are we talking about?
Krishna Moorthy: In the ones we demonstrated,
we were talking about a 75 KVA system
at 480 volts AC, but these can be scaled
for higher power and higher voltages.
Tech Briefs: Can you tell us a bit more
about the overall architecture?
Krishna Moorthy: To put it in the simplest
terms: If, for example, I want to
build a 250-kilowatt inverter, it will have,
say, five IPSs that each are rated for 50
kilowatts, as well as other subcomponents
including passive elements, auxiliary power
circuits, etc. These in turn will work together
to deliver the 250 kilowatts.
Our guiding philosophy is that if one
IPS fails, I will still be able to operate the
others rather than bringing the whole
system down.
Tech Briefs: What do you see as the
next step in this project?
Krishna Moorthy: The big thing I am
working on is to integrate the SUPERs in
a node like a microgrid and see how beneficial
they are to the microgrid at the top
level. Also, to see the sorts of control flexibilities
I can get with the greater amount
of data that I'm getting downstream.
To read the full interview, visit www.
techbriefs.com.
Tech Briefs, June 2023
http://info.hotims.com/84480-723 http://www.techbriefs.com http://www.techbriefs.com
Tech Briefs Magazine - June 2023

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