Program features
32
Motor identification
The performance of Direct Torque Control is based on an accurate motor model
determined during the motor start-up.
A motor identification magnetization is automatically done the first time the start
command is given. During this first start-up, the motor is magnetized at zero speed
for several seconds to allow the motor model to be created. This identification
method is suitable for most applications. However, as previously stated, for winding
applications, a separate identification run must be performed.
Settings
Parameter
99.10.
Power loss ride-through
If the incoming supply voltage is cut off, the drive will continue to operate by utilizing
the kinetic energy of the rotating motor. The drive will be fully operational as long as
the motor rotates and generates energy to the drive. The drive can continue the
operation after the break if the main contactor remained closed.
Note: Cabinet assembled units equipped with main contactor option have a “hold
circuit” that keeps the contactor control circuit closed during a short supply break.
The allowed duration of the break is adjustable. The factory setting is five seconds.
130
260
390
520
1.6 4.8 8 11.2 14.4
t (s)
U
DC
f
out
T
M
U
DC
= Intermediate circuit voltage of the drive, f
out
= output frequency of the drive,
T
M
= Motor torque
Loss of supply voltage at nominal load (f
out
= 40 Hz). The intermediate circuit DC voltage drops to the
minimum limit. The controller keeps the voltage steady as long as the supply is switched off. The drive
runs the motor in generator mode. The motor speed falls but the drive is operational as long as the
motor has enough kinetic energy.
U
mains
20
40
60
80
40
80
120
160
T
M
(Nm)
f
out
(Hz)
U
DC
(VDC)
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