ADV200 • Quick start up guide - Specification and installation
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5.3 Braking
There are various possible types of braking:
-
Internal Braking Unit
-
Injection of direct current from the Inverter into the motor (D.C. braking)
There are two essential differences between the two braking methods:
-
A braking unit can be used for speed reduction (e.g.: from 1000 to 800 rpm),
whereas D.C. braking can only be usedfor braking to standstill.
-
The energy in the drive is converted into heat in both cases. This conversion
takes place in a braking resistor encased in the braking unit. With D.C. brak-
ing, the energy is converted into heat in the motor itself, resulting in a further
rise in motor temperature.
5.3.1 Braking unit
Frequency-regulated asynchronous motors during hyper-synchronous or regen-
erative functioning behave as generators, recovering energy that
fl
ows through the
inverter bridge, in the intermediate circuit as continuous current.
This leads to an increase in the intermediate circuit voltage.
Braking units (BU) are therefore used in order to prevent the DC voltage rising
to an impermissible value. When used, these activate a braking resistor 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.
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
)
1007
Internal Braking
Units (standard
internal)
5.7
8
100
1015
5.7
8
100
1022
5.7
8
100
1030
5.7
8
100
1040
5.7
8
100
2055
8.5
12
67
2075
8.5
12
67
2110
15.5
22
36
3150
22
31
26
3185
37
53
15
3220
37
53
15
4300
Internal Braking
Units (standard
internal)
57
80
10
4370
57
80
10
4450
76
107
7.5
5550
76
107
7.5
≥
73550
External Braking Unit
(optional)
