Evaluation Engineeering - 8

REGENERATIVE POWER SUPPLIES & SOURCES

output voltage ranges to support everincreasing EV battery pack power levels,
which requires higher battery voltage to
keep current levels and associated cabling
and connectors in-check. This results in
products with capabilities to 1500Vdc and
more becoming more prevalent in recent
years. Another trend is the need for multichannel battery test systems based on regenerative DC source/sink power supplies
to support testing multiple battery packs
simultaneously."
Martin Weiss, product director at NH
Research: "As electrification continues
to accelerate across many industries, we
are seeing two key technology trends in
regenerative power supplies and sources
that are bidirectional. On the DC side, we
are seeing increased use of regenerative
power supplies as battery emulators, and
in AC we are seeing increased demand for
grid simulation. A battery emulator is a bidirectional DC source solution that simulates a battery, while a grid simulator is an
AC source solution that simulates a wall
outlet. Regenerative bidirectional sources
with battery emulation and grid simulation capabilities provide significant testing
advantages in industries such as electric
vehicles (EV), solar (PV), energy storage
systems (ESS), aerospace and defense."
Eric Turner, general manager of EA
Elektro-Automatik: "Higher power,
higher voltage, and higher efficiencies.
Regenerative, bidirectional power supplies
are now the choice test & measurement
devices for e-mobility, aviation, and renewable energy sources. High power density
battery packs lead to higher power storage
capacities. The aviation industry is moving from hydraulics to electric power, and
hardware like landing gear and flaps use
large amounts of DC power, specifically
inrush current of motors. Renewable energy storage devices include large battery
packs and battery management systems
(BMS). Within these application segments,
power requirements range from 2,000W to
2MW. To decrease current, which drives
smaller and more efficient devices, we've
seen voltages rise from the neighborhood
of 600Vdc to well above 1,500Vdc and more
recently up to 2,000Vdc."

EVALUATION ENGINEERING SEPTEMBER 2019

Sponsored by

Keysight's
RP7953A
regenerative
power system.

Allison Harvey-Goodman, product manager at Keysight Technologies: "One trend
in regenerative power supplies is for
higher voltages of 500V and above, and
higher power of 10kW and more. With the
rapid growth in automotive and energy
markets-driven primarily by the growth
in hybrid-electric and electric vehicles
(HEV/EV)-comes the need for higher
voltage, and higher power regenerative
sources. As the automotive market transitions to HEV/EV, and battery voltages
have shifted from 12V to well over 300V
and power in the tens of kilowatts, high
voltage, high-power regenerative supplies
are needed to adequately emulate and
test these HEV/EV batteries. Conversely,
as more low-voltage subsystems replace
mechanical ones, the total amount of current inside a vehicle can rapidly increase
to tens or hundreds of amperes, thus driving the need for high-current regenerative
power supplies."
Brian Hsu ,
USA product
marketing
mana ger at
AC Power Corp.
(Preen): "There
are more and
more requirements on the
regenerat ive
AC grid simulator and regenerative DC
power supply.
The regenerative AC grid
simulators are
mainly applied
AC Power
on grid tie de- Corporation's PAS-F45
grid simulator.
vices and smart
grid/micro grid-related equipment testing. The regenerative DC power supplies
are used in energy storage, battery testing, DC motor, etc."

Dr. Raghavan Nagarajan, senior staff
application engineer - wind and T&D
expert - at Infineon Technologies: "In
regenerative sources such as wind energy,
the main technology trend is going for
high power-rated wind turbines for both
onshore and offshore wind sites."

Challenges
What key challenges are regenerative
power supply & source vendors or their
partners facing today?
Harvey-Goodman, Keysight: "Many applications for regenerative power supplies
in aerospace defense, infrastructure, and
automotive are high-power in nature and
present unique challenges that were
not relevant in low-power applications.
Testing at high power is not a simple extension of low power; it's a lot more complicated. Some of the key challenges that
companies must now consider are site
preparation necessities, and safety requirements when transitioning from
low power to high power. Multikilowatt output power supplies
generate tremendous amounts of
heat, often requiring the addition
of a cooling infrastructure."
Tur ner, Elekt ro -Automat ik :
"Market demands of f lexibility,
reduction in physical space requirements and cost. In many applications subassembly test could
be required prior to full assembly
test. As example, Engineers ask for
the flexibility to separate (Master/
Slave) a 1MW regenerative DC supply into four 250kW systems instead
of purchasing one large supply and several smaller ones. As always, floor space
is valuable and often in short supply so
our customers value smaller solutions. In
general, regenerative supplies are priced
at $/Watt and customers expect cost savings as power increases."

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Evaluation Engineeering

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