C h a p t e r 4
DESIGNING FOR EFFICIENCY
Achieving the best driving range possible
is arguably the most significant challenge
that EV designers face. On the lowest
level, this means designing a vehicle
that can most effectively store electrical
energy and convert it into usable kinetic
energy for driving.
EV designers should strive to create
the most efficient vehicle electrification
systems possible. On a high level,
electrical efficiency is important because
it will play a significant role in determining
how much stored electrical energy can
be converted into usable driving energy.
Beyond this, however, electrical efficiency
is an important metric for overall
sustainability, which is the ultimate goal of
EVs.
While many different variables and
subsystems impact a vehicle's efficiency,
the EV powertrain is one area of
particular interest. The EV powertrain is
designed to take stored DC energy from
the battery, convert it to AC, and supply
that AC to the motor where it is converted
to the kinetic energy of the spinning
wheels.
The powertrain's traction inverter—which
is responsible for converting DC from the
battery to AC for the motor—is especially
important from an efficiency perspective.
A typical traction inverter system consists
of a BMS that controls the battery and
charges a DC link capacitor. This provides
the power to the traction motor controller,
which consists of a motor control unit,
Vincent McNeil
Director of Segment Line, NXP Semiconductors
If you consider an EV end to end,
you have efficiencies going from
the battery where you're storing
the energy, down to the traction
inverter, and then eventually into
the spinning of the car wheels.
A designer's goal is to maximize
the efficiency of each of these
systems."
17
7 Experts on Designing Vehicle Electrification Solutions
