Truck & Off-Highway Engineering - April 2024 - 24

Overcoming EV drivetrain testing
CHALLENGES
TESTING | ELECTRIFICATION FEATURE
Randal Beattie,
President
at SAKOR
Technologies.
they are typically not acceptable for
powering the DC components of a hybrid/EV
test system. A standard offthe-shelf
power supply will not work,
because it cannot absorb power from
the regenerative system and may be
damaged or destroyed.
SAKOR developed a Solid-State
" To accurately test a
high-voltage hybrid
or electric drivetrain,
the test system must
provide precise,
repeatable highvoltage
DC power. "
   
Battery Simulator/Test System specifically
to test high-voltage hybrid vehicle
batteries and simulate these batteries in
an electric drivetrain environment. At
the heart of the system lies a high-efficiency,
line-regenerative DC power
source. During regenerative modes, absorbed
power is regenerated back to the
AC mains instead of being dissipated as
waste heat, which is common practice
among previous-generation testing systems.
This method provides much greater
power efficiency and measurably reduces
overall operating costs.
Coupled with DynoLab, the SolidState
Battery Simulator/Tester accurately
simulates the response of the high-voltage
battery in real-world conditions.
However, since it is not subject to a variable
charge state, it provides repeatable
results. This same unit, when operated as
a battery tester, subjects the battery to
the same charge/discharge profile as it
would encounter in an actual vehicle on
an actual road course.
One of the advantages of using the
AC dynamometer with a regenerative
DC power source is that when the two
are coupled together, the power absorbed
by one unit can be recirculated
back to the other unit within the test
system. This greatly reduces the power
drawn from the AC mains - by as much
as 85% to 90% - and therefore significantly
reduces total cost of operation.
Low maintenance requirements also
contribute to lowering operating costs.
Communication with
control modules
Communication with individual MCUs is
another feature that must be built into
testing systems for hybrid or electric
vehicles. In the past, the engine was
primarily controlled using the throttle
and ignition. Now, engines have an engine
control unit (ECU), the vehicle will
likely have a separate MCU that controls
the electric drive and may have separate
units for controlling the transmission
and/or charging systems.
These units typically communicate
  
    
       
     
   
    
    
       
     
 
   
24 April 2024
commands and/or data between themselves
via high-speed vehicle networks,
such as CAN, LIN, FlexRay, etc. To properly
test this complex drivetrain configuration,
the test system must be able to
communicate with these control units
simultaneously and efficiently.
There is great excitement in the automotive,
heavy equipment, military and
aerospace industries over the promise
of improved environmental performance
of hybrid and electric vehicles.
To achieve that promise, driveline testing
programs must be adopted that
meet the needs of these technologies.
Randal Beattie, President at SAKOR
Technologies Inc., wrote this article submitted
to Truck & Off-Highway Engineering.
TRUCK & OFF-HIGHWAY ENGINEERING
SAKOR TECHNOLOGIES

http://info.hotims.com/86280-708

Truck & Off-Highway Engineering - April 2024

Table of Contents for the Digital Edition of Truck & Off-Highway Engineering - April 2024