Method To Calculate The Continuous Braking Power; Connection Of An External Braking Resistor - Moog MSD Operation Manual

4.16.4 Method to calculate the continuous braking power:

y Calculation of effective servo drive utilisation in
a cycle T:
y Determination of permissible continuous braking
power based on unused drive power:
Boundary conditions
y A single braking action must not exceed the
maximum pulse energy of the braking resistor.
y The continuous braking power calculated for the
device must be greater than the effective braking
power for a device cycle.
This results in the minimum permissible
cycle time T with calculated continuous
braking power:
The maximum total on-time of the braking
resistor over a specified cycle time T with
calculated continuous braking power is:
moog
ID no.: CA65642-001 06/2018
Electrical installation
T
1
∫
2
I = i dt
eff
T
T
0
1
T ∫
2
I = 1 i dt
T
∫
1
eff
I T i 2 dt
= ∫
2
I = i dt
eff
T
0
 
eff
T T
I
1
  0  
eff
∫
P 1 K 1
= − 0 ×
2
I = i dt
DBr
 I 
eff
T
N
 
0
I
   
 
eff
P = 1 − I × K 1
 
   
I
DBr
eff
 I 
P = 1   − ×   K 1
eff
P = 1 − × K 1
N
DBr
 I 
T
DBr
 1 
 I 
N
I
∫
P ≥ × N P dt
   
eff
P = 1 − × K 1
DBr PBr Br
T
DBr
 I 
0
N
T
1
W ≥ P x T
∫
IBr T PBr Br
P ≥ × P dt
1
T
1
DBr ∫ PBr Br
P P dt
≥ T ×
∫
P ≥ × P dt
DBr PBr Br
T 0
DBr PBr Br
T T
1
0
T
P
∫ 0
P ≥ × P dt
∫
PBr
T = × dt
DBr PBr Br
T
Br
P
0
0
DBr
T
P
∫
T
T = PBr ×
P dt
T
P
Br
∫
PBr
T = × dt
P
∫
T = PBr × dt
Br
DBr 0
P
Br
T
P P
0
DBr
∫
T = PBr × 0
DBr dt
Br
P
P
0
DBr
DBr
T = × T
BrSum P
PBr
P
DBr
T = P × T
P
BrSum P
DBr
T = × T
DBr
T = × T
PBr
BrSum P
P
BrSum P
PBr
DBr
T = PBr × T
BrSum P
PBr

4.16.5 Connection of an external braking resistor

NOTE:
Be sure to follow the installation instructions for the external braking resistor.
The temperature sensor (bimetallic switch) on the braking resistor must be
wired in such a way that the power stage is deactivated and the connected
servo drive is disconnected from the mains supply if the braking resistor
overheats.
The minimum permissible connection resistance for the servo drive must not
be infringed, for technical data see chapter A.2.
The braking resistor must be connected using a shielded cable.
K
1
L
1
L
2
L
3
*)
K
1
2)
*) Depending on how the temperature sensor is connected, the nature and magnitude of the control voltage, the power required by the mains contactor, it
may be necessary to provide an auxiliary contactor.
1) Temperature switch, temperature sensor, bimetallic switch
2) Control voltage
Figure 4.21 Connection of braking resistor
MSD Single-Axis System Operation Manual AC-AC Servo Drive
U
V
M
W
1)
L+
R
B
R
B
47