Lenze DSD - Manual (Page 373)

Lenze · Drive Solution Designer · Manual · DMS 4.2 EN · 12/2013 · TD23
373
12 Components in the DC bus
12.6 Brake resistor selection
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12.6.5.2 Brake transistor in the power supply module or regenerative power supply module
The following power supply modules and regenerative power supply modules have an integrated
brake transistor to which brake resistors can be connected to.
• 9400 power supply module
• 9400 regenerative power supply module
• i700 power supply module
The simulation of device-internal monitoring functions serves for the evaluation of the power de-
mand by DSD and the determination of the utilisation of the power supply module or regenerative
power supply module.
[12-5] Power supply module or regenerative power supply module diagram: integrated brake transistor utilisation
Description
P
sum
(t) Total power in generator mode in the DC bus over time
P
av,Brm
Average braking power on the brake transistor, considering the thermal time constant (τ ~
th,Brm
)
P
max,Brm
Peak braking power of the brake transistor
P
N,Brm
Continuous braking power of the brake transistor
A
th,Brm
Thermal utilisation of the brake transistor.
• Possible message: The permanent utilisation of the brake transistor is xxx %. Thus the limit
value of 100 % is exceeded.
A
Brm
(P
max
) Utilisation of the brake transistor relative to the peak braking power
• Possible message: The max. utilisation of the brake chopper is xxx %. Thus the limit value of
100 % is exceeded.
τ
~
th,Brm
Thermal time constant for checking the brake transistor
ED
Brm
Relative operating time of the brake resistor (pulse-pause ratio)