Toshiba TOSVERT VF-AS1 Instruction Manual page 150

Precautions on auto-tuning 1
(1) The inverter is tuned automatically (auto-tuning 1
time after setup. During auto-tuning 1, which takes several seconds, the motor is energized, although
it is standing still. Noise may be produced by the motor during auto-tuning 1, which, however, does
not indicate that something is wrong with the inverter or the motor.
(2) Conduct auto-tuning 1 (
completely stopped.
If auto-tuning is conducted immediately after operation stops, the presence of a residual voltage may
result in abnormal tuning.
(3) Usually, auto-tuning terminates in some seconds. If an error occurs, however, the inverter trips
(display
Selection 3 described below.
(4) It may not be possible to tune automatically special motors such as high-speed motor or high-slip
motor. For these motors, perform manual tuning using Selection 3 described below.
(5) Provide cranes and hoists with sufficient circuit protection such as mechanical braking. Without
sufficient circuit protection, the result of insufficient motor torque during tuning could create the risk of
the machine stalling/failing.
(6) If auto-tuning is impossible or an auto-tuning error (
Selection 3.
Precautions on vector control
[Selection 3: Setting sensorless vector control and manual
independently]
6
Setting motor constants
Perform all operations in the flowchart on the previous page. If the motor specifications are unknown, enter only the
motor capacity (
the following explanation about parameter adjustments as a guide.
This section describes how to set motor constants. Select the items to be improved and change the related motor
constants.
(1) Slip frequency gain
This parameter is to adjust the slippage of the motor.
Setting this parameter at a larger number can reduce the slippage of the motor. However, setting it at an
excessively large number may result in hunting, etc., and thus cause an unstable operation.
(2) Motor constant 1
This parameter is to adjust the primary resistance of the motor. Setting this parameter at a larger value can prevent
the drop of the motor torque in low speed ranges due to a voltage drop. However, setting it at an excessively large
number may result in large current in low speed range and appearance of an overload trip, etc.
(3) Motor constant 2
This parameter is to adjust the exciting inductance of the motor. The larger the set value, the more exciting current
can be increased. Note that specifying a too large value for the motor constant may cause hunting.
(4) Motor constant 3
This parameter is to adjust the leakage inductance of the motor. The larger the set value, the larger torque the
motor can produce in high-speed ranges.
(5) Motor constant 4
This parameter is to adjust the secondary resistance of the motor. The amount of compensation for slip increases
with increase in this value.
(6)
This parameter is used to adjust the excess response speed. Specifying a large value reduces the amount of
overshoot at the completion of acceleration. So, specify a value appropriate to the actual moment of inertia of the
load.
= ) only after the motor has been connected and operation
) and no motor constant is set. For these motors, perform manual tuning using
⇒
Refer to Section 5.6,8).
) and set parameter
(Torque boost) (Motor test reports may be useful.)
(No-load current) (Motor test reports may be useful.)
(Leak inductance) (Motor test reports may be useful.)
(Rated slip)
(Moment of inertia of load)
= ) when the inverter is started for the first
) is displayed, perform manual tuning with
to . After that, run the motor and set other parameters with
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