Parameter Description

Issue 01/06

3.26Compound braking

P1236[3] Compound braking current

 

Min:

0

CStat:

CUT

Datatype: U16

Unit: %

Def:

0

P-Group:

FUNC

Active: Immediately

QuickComm.: No

Max:

250

Level

2

Defines DC level superimposed on AC waveform after exeeding DC-link voltage threshold of compound braking. The value is entered in [%] relative to rated motor current (P0305).

If P1254 = 0 :

 

 

Compound braking switch-on level

UDC_Com p =

1.13 2 Vm ains = 1.13 2 P0210

otherwise :

 

 

Compound braking switch-on level

UDC_Comp =

0.98r1242

The Compound Brake is an overlay of the DC brake function with regenerative braking (effective braking at the ramp) after OFF1 or OFF3. This enables braking with controlled motor frequency and a minimum of energy returned to the motor. Through optimization of the ramp-down time and the compound braking an efficient braking without additional HW components is possible.

P1236 = 0

Without Compound braking

f

f

f_set

 

 

 

f_act

 

 

 

t

 

 

i

 

 

t

uDC-link

u

P1236 > 0

With Compound braking

f_set

f_act

t

i

t

DC-link

 

UDC_Comp

t

t

Index:

P1236[0] : 1st. Drive data set (DDS)

P1236[1] : 2nd. Drive data set (DDS)

P1236[2] : 3rd. Drive data set (DDS)

Value:

P1236 = 0 :

Compound braking disabled.

P1236 = 1 - 250 :

Level of DC braking current defined as a [%] of rated motor current (P0305).

Dependency:

Compound braking depends on the DC link voltage only (see threshold above). It will be active with OFF1/OFF3 and at regenerating conditions.

It is disabled, when:

-DC braking is active

-Flying start is active

-Vector mode (SLVC, VC) is selected

Notice:

Increasing the value will generally improve braking performance; however, if you set the value too high, an overcurrent trip may result. If used with dynamic braking enabled as well compound braking will take priority. If used with the Vdc max controller enabled the drive behaviour whilst braking may be worsened paticularly with high values of compound braking.

Compound braking does not function when the drive is in vector control.

146

MICROMASTER 440 Parameter List

6SE6400-5BB00-0BP0

Page 146
Image 146
Siemens 440 manual P12363 Compound braking current, 146, Datatype U16 Unit % Def Group