Quattro DC Drive Operation and Feature Overview
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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,
there will be no timed delay for current ramp-
down. This time may be adjusted by the
function RAMPED STOP TIME (A1).
Motor Field Current Control and Field
weakening
DC elevator motors have a separately excited
shunt field. Adjustments include Stand-By
Current, Full-Field Current and Weak-Field
Current, all programmed in amperes, and a
Flux Confirm Level, programmed as a % of
Full-Field. With no active Full-Field or drive
Run command motor field current would
normally be at Stand-By amps. An active
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