Magnetek HPV 900 Series 2, Technical Manual

Page: 116 / 230

User Switches C1 Submenu
94
drive senses the motor is above a defined
speed level. The defined speed level is
determined by the gain change level
parameter.
An example of internal high / low gain control
is shown below.
High / Low Gain Example i
, ii
RAMPED STOP SEL
i,ii
(Ramp Stop Select) This parameter allows
the selection of the Torque Ramp Down Stop
function. This function is used to gradually
remove the torque command after the elevator
has stopped and the mechanical brake has
been set. This prevents a shock and possible
‘bump’ felt in the elevator from the torque
signal going to zero too quickly.
A function unique to elevators involves the
interaction between the motor torque and the
mechanical brake that holds the elevator.
Under full load conditions at the end of a run, if
the brake is set and the motor torque is
removed quickly, some brake slippage may
occur. Therefore, the option of gradually
reducing the motor torque is provided by the
Torque Ramp Down Stop function.
Upon being enabled by the Ramped Stop
Select Parameter (RAMPED STOP SEL(C1)),
i
Parameter accessible through CLOSED LOOP (U9)
ii
Parameter accessibly through PM (U9)
the torque command is linearly ramped to zero
from the value that was present when the
‘Ramp Down Enable’ was selected.
The Ramp Down Enable has the following
three possible sources:

An input logic bit (EXTERNAL TB1)

The run logic
– initiated by the removal of
the run command

The serial channel
The Ramp Down Enable Source parameter
(RAMP DOWN EN SRC(C1)) is used to select
one of the above options.
A method of providing the Ramp Down Enable
would be with a logic signal (EXTERNAL TB1)
that is dedicated to that function. The Ramp
Down Enable would be asserted while the Run
command is still present and remain there until
the ramp is completed, after which the Run
command would be removed.
The RUN LOGIC option to trigger the Ramp
Down Enable from the Run command is
provided. In this case, removal of the Run
command enables the Ramp Down Stop
Function.
The time it takes for the HPV 900 Series 2 to
perform its ramped stop is determined by the
Ramped Stop Time Parameter. The Ramped
Stop Time parameter (RAMPED STOP
TIME(A1)) selects the amount of time it would
take for the drive to ramp from the rated torque
to zero torque.
iii
Parameter accessible through OPEN LOOP(U9)
10%
contract
speed
HPV 900 Series 2 Parameter
Settings
HI/LO GAIN SRC = internal
GAIN REDUCE MULT = 80%
GAIN CHNG LEVEL = 10 %
RESPONSE = 10.0 rad/sec
0%
contract
speed
low gain
mode
Response of
Speed
Regulator
8.0 rad/sec
10%
contract
speed
Response of
Speed
Regulator
8.0 rad/sec
Response of
Speed Regulator
10.0 rad/sec
0%
contract
speed
Response of
Speed Regulator
10.0 rad/sec
speed
reference
100%
contract
speed