ABB ACS280, Руководство по прошивке, Страница: 37 / 430

Program features 37

Vector control
Vector control is the motor control mode which is intended for applications
where high control accuracy is needed. It offers better control over the whole
speed range, in particular in applications where slow speed with high torque is
needed. It requires a motor identification at startup. Vector control cannot be
used in all applications, e.g. there are multiple motors connected to single drive.
The switching of the output semiconductors is controlled to achieve the
required stator flux and motor torque.
Motor control requires measurement of the DC voltage and two motor phase
currents. Stator flux is calculated by integrating the motor voltage in vector
space. Motor torque is calculated as a cross product of the stator flux and the
rotor current. By utilizing the identified motor model, the stator flux estimate is
improved. Actual motor shaft speed is not needed for the motor control.
The best motor control accuracy is achieved by activating a separate motor
identification run (ID run).
See also section
Speed control performance figures
on page
47
.
Settings and diagnostics
Parameters 99.04 Motor control mode (page 288 ) and 99.13 ID run requested
(page
291
).
Events: -

Reference ramping
Acceleration and deceleration ramping times can be set individually for speed,
torque and frequency reference.
With a speed or frequency reference, the ramps are defined as the time it takes
for the drive to accelerate or decelerate between zero speed or frequency and
the value defined by parameter (
46.01
or
46.02
). The user can switch between
two preset ramp sets using a binary source such as a digital input. For speed
reference, also the shape of the ramp can be controlled.
With a torque reference, the ramps are defined as the time it takes for the
reference to change between zero and nominal motor torque (
01.30 )
.
Special acceleration/deceleration ramps
The acceleration/deceleration times for the jogging function can be defined
separately; see section
Jogging
on page
43
.
The change rate of the motor potentiometer function (page 85 ) is adjustable.
The same rate applies in both directions.
A deceleration ramp can be defined for emergency stop (“Off3” mode).