9 braking operation/brake energy management, Braking operation/brake energy management, 5motor control (mctrl) – Lenze E84DSxxx User Manual
Page 170
5
Motor control (MCTRL)
5.9
Braking operation/brake energy management
170
Lenze · 8400 protec StateLine · Reference manual · DMS 4.2 EN · 03/2013 · TD05
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5.9
Braking operation/brake energy management
When electric motors are braked, the kinetic energy of the drive train is fed back into the DC circuit
regeneratively. This energy leads to an increase in the DC bus voltage. In order to avoid overvoltage
in the DC bus, several different strategies can be used:
• Use of a brake resistor
• Stopping of the ramp function generator if brake chopper threshold exceeded (RFG_Stop)
• Use of the "inverter motor brake" function
• Combination of the above named options
In the case of inverters with a 3-phase supply, the following is also possible:
• Coupling of the inverters in a DC-bus connection
• Recovery of regenerative energy with a regenerative module
, a ramp function generator stop (FB
) can be set for instances when the
brake resistor is controlled. This prevents overvoltage deactivation in the case of short
deceleration times.
Selecting the response to an increase of the DC-bus voltage
Stop!
If the connected brake resistor is smaller than required, the brake chopper can be
destroyed!
Appropriate protective measures are described in subchapter "
overload of the brake resistor
Note!
• We recommend to use the brake chopper (brake transistor) which is integrated into
the controller for the braking operation, regardless of the selected motor mode.
• Connect the required brake resistor to the R
B1
and R
B2
terminals of the controller.
• For a DC-bus connection with other devices, we recommend to connect the
regenerative power supply module to terminals +UG and –UG.
• If none of these measures is taken, e.g. the overvoltage deactivation ("OU") may
respond in case of low deceleration times during regenerative operation.
messages of the operating system
To install the regenerative module, follow the instructions in the 8400 hardware
manual.
• The hardware manual has been stored in electronic form on the data carrier supplied
with the 8400 drive controller.