Def / Type
FbEq 16b / 32b
DescriptionName / Range /
Selection
No.
3Brake chopper starts to conduct at 100% pulse width
whenever
• The DC voltage exceeds the overvoltage fault limit
(a hysteresis applies), and
• The drive is not modulating (for example, during a
coast stop).
The thermal model-based resistor overload protection is
not active.
This setting is intended for situations where
• The braking chopper is not needed for runtime
operation, ie. to dissipate the inertial energy of the
motor,
• The motor is able to store a considerable amount of
magnetic energy in its windings, and
• The motor might, deliberately or inadvertently, be
stopped by coasting.
In such a situation, the motor would potentially discharge
enough magnetic energy towards the drive to cause
damage.
To protect the drive, the brake chopper can be used with
a small resistor dimensioned merely to handle the magnetic
energy (not the inertial energy) of the motor.
Overvoltage peak
protection
On / uint32Selects the source for quick brake chopper on/off control.
0 = Brake chopper IGBT pulses are cut off
1 = Normal brake chopper IGBT modulation allowed.
This parameter can be used to enable chopper operation
only when the supply is missing from a drive with a
regenerative supply unit.
Brake chopper run
enable
43.7
00.Off
11.On
See Terms and abbreviations (page 132).
Other [bit]
0 s / real32Defines the thermal time constant for the brake resistor
thermal model.
Brake resistor thermal
tc
43.8
1 = 1 s / 1 = 1 sBrake resistor thermal time constant, ie. the rated time to
achieve 63% temperature.
0...10000 s
0.00 kW / real32Defines the maximum continuous load of the brake resistor
which will eventually raise the resistor temperature to the
maximum allowed value (= continuous heat dissipation
capacity of the resistor in kW) but not above it. The value
is used in the resistor overload protection based on the
thermal model. See parameter 43.6 Brake chopper
function, and the brake resistor data sheet.
Brake resistor max
cont power
43.9
1 = 1 kW / 1 = 1 kWMaximum continuous load of the brake resistor.0.00 ... 10000.00 kW
0.0 Ohm / real32Defines the resistance value of the brake resistor. The
value is used for the brake chopper protection based on
the thermal model. See parameter 43.6 Brake chopper
function.
Brake resistance43.10
Parameters 393
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