30
ADV200 SP • Quick start up guide - Specification and installation
5.3 Braking
There are various possible types of braking:
- via internal braking unit and external braking resistor (up to size ADV
5750),
- via external braking unit (BUy, usable for all sizes),
- Injection of direct current from the Inverter into the motor (D.C. braking)
- through a special overflux function (AC braking) available if V/F control is selected.
The various possibilities have the following key difference:
- Using a braking unit or the AC braking function it is possible to control a speed reduction (for example form
1000 to 800rpm) while the DC braking can only used to stop the motor.
- Using a braking unit the energy is dissipated into heat in the braking resistor
- Using the AC braking function or the DC braking function, the energy is dissipated into heat in the motor
windings (resulting in a further rise in the motor temperature)
- By using the AC braking function in place of the DC braking, the braking action is more efficient (more brak
-
ing capability) and allows to maintain the same speed control without introducing operational discontinuities.
It means that the AC braking allows the machine to change quickly its behavior from motorizing to braking
when required.
5.3.1 Braking unit
Frequency-regulated asynchronous motors during hyper-synchronous or regenerative functioning behave as
generators, recovering energy that flows through the inverter bridge, in the intermediate circuit as continuous
current.
This leads to an increase in the intermediate circuit voltage.
Braking units (internal to drive or external BUy) are therefore used in order to prevent the DC voltage rising to
an impermissible value. When used, these activate a braking resistor (external to drive) that is connected in
parallel to the capacitors of the intermediate circuit. The feedback energy is converted to heat via the braking
resistor (R
br
), thus providing very short deceleration times and restricted four-quadrant operation.
Note!
An optional BUy braking unit connected to terminals C and D can be used. For further details reference should be
made to the BUy manual.
Recommended combination braking resistors: see chapter
“10.8 Braking resistor (optional)”, page 100.
Sizes
Technical data of the Internal Braking Units (Duty 50%)
Nominal current of the
internal braking unit
I
rms
(A)
Peak current
I
pk
(A)
Minimum braking
resistance value
R
br
(
Ω
)
1015
Internal Braking Units
(standard internal)
5.7
8
100
1022
5.7
8
100
1030
5.7
8
100
1040
5.7
8
100
1055
5.7
8
100
2075
8.5
12
67
2110
8.5
12
67
2150
15.5
22
36
3185
22
31
26
3220
37
53
15
3300
37
53
15
4370
Internal Braking Units
(standard internal)
57
80
10
4450
57
80
10
4550
76
107
7.5
5750
76
107
7.5
Summary of Contents for ADV200 SP Series
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