SSD 605C Product Manual - page 92
6-26
Programming Your Application
605C Frequency Inverter
DYNAMIC BRAKING
The dynamic braking function block
controls the rate at which energy from a
regenerating motor is dumped into a
resistive load. This dumping prevents the
internal voltage in the Inverter from
reaching levels which could damage the
Inverter electronics.
Functional Description
When enabled, the Dynamic Braking block monitors the internal dc link voltage every milli-
second and sets the state of the brake switch accordingly.
The dynamic braking block provides a control signal that is operated on by the slew rate limits
block. This causes the setpoint to be temporarily frozen whenever the dc link voltage exceeds
the internal comparison level. This allows the stop rate to be automatically tuned to the
characteristics of the load, motor, Inverter and brake resistor.
The dynamic braking block operates even when the motor output is not enabled. This allows the
block to continually monitor the energy dumped into the braking resistor, and the energy
dissipated across the brake switch. With this information the Inverter is able to deduce the
loading on the brake resistor. An optional trip may be enabled should the resistor be loaded
beyond its capabilities.
Refer also to Chapter 13: “Application Notes” - Dynamic Braking.
MMI Menu Map
1 SETUP PARAMETERS
2 FUNCTION BLOCKS
3 MOTOR CONTROL
4 DYNAMIC BRAKING
BRAKE ENABLE
BRAKE RESISTANCE
BRAKE POWER
BRAKE 1S RATING
DC LINK VOLTS
BRAKING
DYNAMIC BRAKING
DC LINK VOLTS
[ 75] –0.0 V
BRAKING
[ 81] –FALSE
TRUE – [ 80] ENABLE
–
100 Ohm – [ 77] BRAKE RESISTANCE
–
0.1 kW – [ 78] BRAKE POWER
–
25 – [ 79] 1 SEC OVER RATING
–
Parameter Descriptions
ENABLE
Range: FALSE / TRUE
Enables operation of the dynamic braking block.
BRAKE RESISTANCE
Range:1 to 1000 Ohm
The value of the load resistance.
BRAKE POWER
Range: 0.1 to 510.0 kW
The power that the load resistance may continually dissipate.
1 SEC OVER RATING
Range: 1 to 40
The power that the load resistance may dissipate for 1 second.
DC LINK VOLTS
Range: xxxx.x V
The internal dc voltage tested by the braking block.
BRAKING
Range: FALSE / TRUE
A read-only parameter indicating the state of the brake switch.