Calculating The Energy Consumption Of The Dynamic Brake Resistor - YASKAWA Sigma-7S Series Product Manual

3.4 Calculating the Energy Consumption of the Dynamic Brake Resistor

3.4

Calculating the Energy Consumption of the Dynamic Brake Resistor

Calculate the energy that must be consumed by the resistance for one dynamic brake stop.
To simplify the energy consumption calculation, assume that all the kinetic energy until the Ser-
vomotor stops is consumed by the dynamic brake resistor and use the following formula.
Out of all possible operation patterns, use the one which maximizes the kinetic energy of the
Servomotor.
Rotary Servomotors
Energy consumption of the dynamic brake resistor: E
Motor moment of inertia*: J
Load inertia: J
Motor speed just before stopping with the dynamic brake: N [min
*
For detailed information on the motor moment of inertia, refer to the catalog or Servomotor product manual.
Linear Servomotors
Energy consumption of the dynamic brake resistor: E
Moving Coil mass*: m
Load mass: m
Motor speed just before stopping with the dynamic brake: v [m/s]
*
For detailed information on Moving Coil mass, refer to the catalog or Servomotor product manual.
3-14
2
[kgm ]
M
2
[kgm ]
L
E
=
DB
[kg]
M
[kg]
L
E
=
DB
[J]
DB
2
1
2π )
+ J ) ×
(
× × N
(J
M L
2 60
[J]
DB
1
+ m ) × v
×
(m 2
M L
2
-1
]