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Quattro DC Drive Operation and Feature Overview
Drive Operation and
Feature Overview
The Quattro DC drive is a velocity and torque
regulated motor drive designed specifically for
operating elevators. Many of the features
described below can be selectively
programmed to customize an individual
application.
Analog Velocity Follower
The elevator car controller provides an analog
velocity reference to the drive at A6TB1-15
and A6TB1-16. The signal may be bi-polar +/-
10 VDC to indicate speed and travel direction,
or a positive only unipolar signal with the
direction of travel selected by logic commands.
In most cases the signal profile will be adjusted
by the car controller for precise landing
positioning. The velocity reference passes
directly to the closed loop velocity controller,
except for an internal rate limiter to buffer any
unexpected electrical noise. Start and Stop
commands are via 24VDC logic inputs.
Calibration of the analog velocity reference
signal may be adjusted with separate gain and
offset parameters. To set the Analog Velocity
Follower, the user must set SPD COMMAND
SRC (C1) to Analog Input.
Preset Speed & Profile Generator
An alternate method of speed control is that
the elevator car controller provides 24VDC
logic input commands to select one of 15 pre-
determined running speeds. The drive
generates a smooth S-Curve acceleration
profile to transition between speed selections.
Either of three separately adjustable ramp
times may be selected. The direction of travel
may be determined by either a Run command
with an Up/Down command signal or by
separate Run-Up / Run-Down logic
commands. To set the Analog Velocity
Follower, the user must set SPD COMMAND
SRC (C1) to Multi-Step, then adjusting Multi-
Step Speed Commands in the Multi-Step
Submenu A3.
Serial Link Follower
The elevator car controller provides the
equivalent of an analog reference command
over a digital serial link. The drive returns
operating status conditions and messages.
Primary run command are 24VDC logic for
redundant safety if wanted. The speed
sensitivity of the serial velocity reference is
adjustable. Enabling the serial link follower
requires SPD COMMAND SRC (C1) to be set
to SERIAL.
Pre-Torque
When enabled, the speed error integrator will
be pre-conditioned by the supplied pre-torque
signal before starting the regulator. This will
cause motor armature current to begin at a
magnitude proportional to the pre-torque
command to prevent elevator motion or
rollback when the elevator brake is released.
The pre-torque signal will be from either an
analog (wired at A6TB1-18 and A6TB1-19) or
serial link digital source as selected by
programming PRETORQUE SOURCE (C1). If
Pre-Torque is not used, leave PRETORQUE
SOURCE (C1) at the defaulted value of none.
An EXT TORQUE BIAS (A1) and an EXT
TORQUE MULT (A1) are available to scale the
pre-torque signal. Ten volts = rated motor
current with a multiplier of 1 and a bias of zero.
Torque Feed Forward
Some car controllers may calculate an
accurate demand for motor torque as required
to accelerate the connected load as well as
hold it against gravity. The torque demand
signal can be programmed to directly drive the
torque control part of Quattro from either an
analog or serial link input. EXT TORQ CMD
SRC (C1) must be set to either analog input or
serial and SPEED REG TYPE (C1) must be
set to either pi speed reg, elev spd reg, or
external reg. The connections for an analog
external torque command source are A6TB1-
18 and A6TB1-19. With an accurate torque
compensating signal, the gain of the PI
regulator can be reduced, to better ignore and
not amplify mechanical vibrations of the hoist
way. Separate adjustments are provided for
torque signal gain and offset. An EXT
TORQUE BIAS (A1) and an EXT TORQUE
MULT (A1) are available to scale the torque
signal. Ten volts = rated motor current with a
multiplier of 1 and a bias of zero.
Torque/Current Ramp-Down
When the drive is told to cease operation by
removal of the Run logic command, (and after
Brake Drop time if that function is engaged)
the armature current reference ramps down to
zero at a constant rate. This allows the
mechanical Brake to gently assume elevator
holding torque, reducing the tendency to
‘thump’ the brake. When armature current
ramp-down is complete, the contactor will be
opened. In the event that the contactor opens
unexpectedly, as reported by the feedback
contact or in the event of a severe drive fault,
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