Fagor QC-PDS, Руководство по оборудованию

Страница: 198 / 420

  
Selection criteria
5.
S
E
LECT
ING CRI
T
ERIA
Ballast resistor selection
guide
· 198 ·
198
Ref.2003
QC-PDS
HARDWARE
5.7 Ballast resistor selection guide
Calculate the value of:
Based on the following formulae:
where:
Wm Energy generated by the braking of each system motor.
Pe Rms power generated by all braking of all the motors throughout
a complete duty cycle.
Jt Total inertia of the servo system (mass of the mobile elements of
the motor and mechanics) with regard to the rotation axis in kg·m².
n Turning speed of the motor when the braking starts (in rpm).
Wmi Energy of each braking during a cycle of time T in Ws.
Wp Potential energy lost by the machine mass while braking (only on
non-compensated axes) (in Ws).
ti Braking time (in seconds) when the Wmi energy is generated.
T Time (in seconds) in a full cycle.
Dh Height (in m) lost while braking .
Wmx Maximum energy among all the Wm.
Pmx Maximum power generated by the braking, given by the maximum
value among all the (Wmi/ti) quotients of each braking (in kW).
Wm Wp
1
2
--- +
Jt
2

n 
60
--------------
2

Ws   =
Wp
m g

h  
= Pe
Wmi
2
ti
-----------
i

T
--------------------
W
 
=
Pmx
Wmi
ti
------------
 
 
 
max
kW
 
=