Closed-loop User Switches C1
107
SPEED REG TYPE
(Speed Regulator Type)
This switch toggles between the Elevator Speed
Regulator (Ereg) and the PI Speed Regulator.
Magnetek recommends the use of the Elevator
Speed Regulator for better elevator
performance.
If set to external regulator, the drive will be
configured as a torque controller.
IMPORTANT
This assumes the car controller is doing its own
closed-loop speed regulation. (i.e. a completely
closed outer speed loop with the car controller
having its own encoder feedback).
The source of the external torque command is
determined by the EXT TORQ CMD SRC (C1)
parameter.
The HPV 600 has the following two closed loop
speed regulation options and an option for
turning off the internal speed regulator:
•
Elevator Speed Regulator (Ereg)
•
PI Speed Regulator
•
External Speed Regulator
The Elevator Speed Regulator is recommended
for use with elevator applications but is not
required. The regulator type can be changed by
using the SPEED REG TYPE (C1) parameter.
Elevator Speed Regulator (Ereg)
The use of the Elevator Speed Regulator allows
the overall closed loop response between speed
reference and speed to be ideal for elevator
applications. The desirable features of the
Elevator Speed Regulator are:
•
no overshoot at the end of accel period
•
no overshoot at the end of decel period
One characteristic of the Elevator Speed
Regulator is that during the accel / decel period
the speed feedback does not match the speed
reference creating a speed error or tracking
delay. As an example, the Elevator Speed
Regulator’s speed response is shown for a
ramped speed reference below.
Ereg Example
The Elevator Speed Regulator is tuned by:
•
System Inertia parameter (INERTIA(A1)),
which is easy to obtain by using the drive
software to estimate the system inertia.
•
Response parameter (RESPONSE(A1)),
which is the overall regulator bandwidth in
radians per sec. This parameter defines the
responsiveness of the speed regulator.
The tracking delay shown is defined as
(1/RESPONSE) seconds. The tracking delay is
not effected by the gain reduce multiplier.
The inner loop crossover parameter (INNER
LOOP XOVER(A1)) should not need to be
changed. But if the number is changed, it must
satisfy the following formula:
multiplier
reduce
gain
response
crossover
loop
inner
×
〈
PI Speed Regulator
When the Proportional plus Integral (PI) speed
regulator is used, the response to a speed
reference is different. As an example, the PI
Speed Regulator’s speed response is shown
below for a ramped speed reference. With the
PI speed regulator, the end of each accel and
decel period, there will be an overshoot. The
amount of overshoot will be a function of the
defined phase margin and response parameters.
speed
feedback
speed error
tracking delay
speed
reference
commanded
speed
no
overshoot
time
speed