5.3 Description of Function Codes
5-94
■ Vector control with speed sensor (F42=6)
This control requires an optional PG (pulse generator) and an optional PG interface card to be mounted on a motor
shaft and an inverter, respectively. The inverter detects the motor’s rotational position and speed according to PG
feedback signals and uses them for speed control. It also decomposes the motor drive current into the exciting and
torque current components, and controls each of components as vectors.
It is possible to obtain the desired response by adjusting the control constants (PI constants) using the speed
regulator (PI controller).
The control method performs speed control with higher accuracy and quicker response than vector control without
speed sensor.
Since slip compensation, dynamic torque vector control, and vector control with speed sensor use motor
parameters, the followi
ng conditions should be satisfied to obtain full control performance.
A single motor is controlled per inverter.
Motor parameters P02, P03, P06 to P20, P55 and P56 are properly configured. Or, auto-
Under vector control without speed sensor
, the capacity of the motor to be controlled must be not less
than two ranks lower of the nominal applied motor capacity
; under vector control with speed sensor, it
is the same as that of the nominal applied motor capacity. Otherwise, the i
nverter may not control the
motor due to decrease of the current detection resolution.
The wiring distance between the inverter and motor should be
164 ft (50 m) or less. If it is longer, the
inverter may not control the motor due to leakage current flow
ing through stray capacitance to the
ground or between wires. Especially, small capacity inverters whose rated current is also small may
be unable to control the motor correctly even if the wiring is less than 164 ft (50 m). In that case, make
the wiring length as short as possible or use a wire with small stray capacitance (e.g., loosely-
cable) to minimize the stray capacitance.
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