Magnetek Quattro DC Elevator Drive Benutzerhandbuch

 

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:  

 

The PI 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. 

The Ramp Down Enable has the following 
three possible sources: 

•  An input logic bit (EXTERNAL TB) 

•  Response parameter (RESPONSE(A1)), 

which is the overall regulator bandwidth in 
radians per sec. This parameter defines 
the responsiveness of the speed regulator. 

 

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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.   
Because of this overshoot, the PI regulator is 
not recommended for elevator control by itself.  
However, the PI regulator is the proper choice 
when a live torque demand signal is available 
from the car controller as an always-active 
Feed-Forward compensating signal.  See 
EXTERNAL TORQ SRC (C1). 
 
 
 
 
 
 
 
 
 
 

 

PI Speed Regulator Example 

 

 

•  Response parameter (RESPONSE(A1)), 

which is the overall regulator bandwidth in 
radians per sec. This parameter defines 
the responsiveness of the speed regulator. 

•  Speed Phase Margin parameter (SPD 

PHASE MARGIN(A1)) is used only by the 

PI Speed Regulator to define the phase 
margin of the speed regulator. 

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)), 
the torque command is linearly ramped to zero 
from the value that was present when the 
‘Ramp Down Enable’ was selected.  

•  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. 

speed 
feedback 

zero tracking delay 

speed

reference

commanded 
speed

overshoot 

time

speed 

A method of providing the Ramp Down Enable 
would be with a logic signal (EXTERNAL TB) 
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 Drive 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.

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