C h a p t e r 1
Motor control technology has
seen remarkable developments
in recent years as a response
to evolving industry demands
and the increasingly diverse
applications of motors. Whether
in low-power portable devices,
industrial machinery, or
cutting-edge drones, precise
and efficient motor control is a
necessity for all applications.
FOC, or vector control, is a
sophisticated method for
controlling motors like BLDC
motors and PMSMs.
On a lower level, FOC uses two
mathematical transformations:
Clarke and Park. The Clarke
transformation converts three-
phase motor currents into two
perpendicular components in
a stationary reference frame,
known as α (alpha) and β (beta).
The Park transformation then
maps these components onto
a rotating reference frame,
resulting in two components:
a direct-axis current (Δd) and
a quadrature-axis current (Δq).
Δd primarily controls flux, while
Δq directly controls torque.
On a higher level, the primary
goal of FOC is to emulate the
control simplicity of DC motors
by decoupling the torque- and
flux-producing components
of motor current. By enabling
independent regulation of
torque and magnetic flux, this
decoupling allows for precise
control of motor performance.
For these reasons, FOC
excels in applications in which
efficiency, noise reduction,
and smooth operation are
required, such as appliances,
drones, and automotive
systems. However, FOC
requires significant processing
power and precise knowledge
of motor parameters such as
resistance and inductance.
Trapezoidal control,
commonly referred to as
six-step commutation or
block commutation, is a
MOTOR CONTROL METHODS
Rui Yin
Electrical Engineer, Vaillant Group
The efficiency of systems
and longevity of batteries
will always be key factors in
motor control design."
6
10 Experts Discuss the Fundamentals of Motor Control
