Download 1.1.1 Capacitor module with 4.1 mF or 20 mF

02.01
1.1.1
Capacitor module with 4.1 mF or 20 mF
Description
The capacitor modules are used to increase the DC link capacitance. This
means that a brief power failure can be buffered and the braking energy can be
temporarily stored.
The modules differ as follows:
Module with 4,1 mF ––> this is used as dynamic energy storage device
Module with 20 mF ––> this is used to buffer power failures
The capacitor modules have a ready display which is lit above a DC link voltage
of approx. 300 V. This also means that an internal fuse failure can be recognized. However, this does not guarantee that the charge condition is reliably monitored.
The module with 4.1 mF does not have a pre–charging circuit which means that
it can save dynamic energy and therefore operate as dynamic energy storage
device as it is direct connected to DC link. For these modules, the charge limits
of the line supply modules must be observed.
The pre–charging for the module with 20 mF is realized via an internal pre–
charging resistor which limits the charge current and de–couples the module
from central pre–charging. With this module, energy cannot be dynamically stored, as the pre–charging resistor limits the charge current. When the power fails,
a diode couples this capacitor battery to the DC link of the system and the capacitor backs–up the DC link voltage.
Note
The capacitance modules may only be used in conjunction with the supply infeeds of SIMODRIVE 611.
The modules are suitable for internal and external cooling.
 Siemens AG 2001 All Rights reserved
SIMODRIVE 611 Planning Guide (PJ) – Edition 04.2001 (preliminary 21.03.2001)
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02.01
LED “READY”
Operating display is
lit above VDC link > 300 V
Capacitor module
Width = 100 mm
or
Equipment bus
(equipment bus
cable is included
in the scope of
supply)
Width = 300 mm
P600
VDC
link
M600
PE
Fig. 1-1
-2
Capacitor module
 Siemens AG 2001 All Rights reserved
SIMODRIVE 611 Planning Guide (PJ) – Edition 04.2001 (preliminary 21.03.2001)
02.01
Technical data
Table 1-1
Technical data of the capacitor module
Designation
Module
4.1 mF
Calculation examples
20 mF
Order No.
6SN1 112–1AB00–0BA0
6SN1 112–1AB00–0CA0
Voltage range
VDC 350 to 750 V
Storage capacity
w = 1/2 x C x U2
VDC steady state (examples)
600 V
––> 738 Ws
680 V
––> 948 Ws
Temperature range
0 C to +55 C
Weight
Approx. 7.5 kg
Approx. 21.5 kg
Dimensions
WxHxD
100 x 480 x 211 [mm]
WxHxD
300 x 480 x 211 [mm]
VDC steady state (examples)
600 V
––> 3 215 Ws
680 V
––> 4 129 Ws
Note:
As a result of the internal pre–
charging resistance, the voltage
at the capacitors is only approx.
0.94 x VDC.
The storage capacity in dynamic operation and when regeneratively braking is calculated as follows:
Formula:
w = ½ x C x (V2DC link max – V2DC lnk n)
Assumptions for the example:
Capacitance of the capacitor battery
C = 4.1 mF
DC link voltage, nominal value
VDC link n = 600 V
DC link voltage, max.
VDC link max = 695 V
––> w = ½ x 4.1 x 10–3 F x ((695 V)2 – (600 V)2) = 252 Ws
The following applies for the storage capacity of the capacitor battery at
power failure:
Formula:
w = ½ x C x (V2DC link n – V2DC link min)
Assumptions for the example:
Capacitance of the capacitor battery
C = 20 mF
DC link voltage, nominal value
VDC link n = 600 V
DC link voltage, min.
VDC link min = 350 V
––> w = ½ x 20 x 10–3 F x ((567 V)2 – (350 V)2) = 1990 Ws
For a DC link voltage of 680 V, the storage capacity increases up to 2904 Ws.
Caution
VDC link min must be 350 V.
For voltages below 350 V, the electronics switched–mode power supply automatically powers–down.
 Siemens AG 2001 All Rights reserved
SIMODRIVE 611 Planning Guide (PJ) – Edition 04.2001 (preliminary 21.03.2001)
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02.01
The possible buffer time tÜ is calculated as follows with the specified DC link
power PZK:
tÜ = w / PZK
Dynamic energy
The DC link capacitors should be seen as storage device. The capacitor module increases the capacitance and the storage capacity.
The energy balance must be determined in order to evaluate the capacitance
required for a specific requirement in a particular application.
The energy balance is dependent on the following:
All moved masses and moments of inertia
Velocity, speed (or its change, acceleration, deceleration)
Efficiencies: Mechanical system, gearbox, motor, inverter (driving/braking)
Buffer time, bypass
DC link voltage and the permissible change, output value, upper/lower limit
value.
In practice, there is often no precise data about the mechanical system. If the
data regarding the mechanical system is determined using approximate calculations or estimated values, the adequate capacitance of the DC link capacitors
can only be determined by carrying–out test during the commissioning phase.
The energy for dynamic operations is obtained as follows:
For the braking or acceleration of a drive from one speed/velocity to another
within time tV, the following applies:
w = ½ x P x tV
for rotary drives with
MMot x (nMot max – n Mot min)
P = ––––––––––––––––––––––––– x ηG
9 550
for linear drives with
P= FMot x (VMot max – VMot min) x 10–3 x ηG
with ηG:
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Braking
ηG= ηM x ηWR
Acceleration
ηG = 1/(ηM x ηWR)
w [Ws]
Energy
P [kW]
Motor output
tV [s]
Duration of the operation
MMot [Nm]
Max. motor torque when braking or accelerating
FMot [N]
Max. motor force when braking or accelerating
nMot max [RPM]
Max. speed at the start or end of the operation
nMot min [RPM]
Min. speed at the start or end of the operation
 Siemens AG 2001 All Rights reserved
SIMODRIVE 611 Planning Guide (PJ) – Edition 04.2001 (preliminary 21.03.2001)
02.01
vMot max [m/s]
Max. velocity at the start or end of the operation
vMot min [m/s]
Min. velocity at the start or end of the operation
ηG
Efficiency, overall
ηM
Efficiency, motor
ηWR
Efficiency, inverter
The torque M and force F which occur are dependent on the moved masses,
the load and the acceleration in the system.
If there is no accurate data for these factors, then generally nominal data are
used.
Information on engineering the modules
The capacitor modules are preferably installed at the righthand end of the system group. The connection is realized via the DC link busbars.
Module with 20 mF (width: 300 mm)
E/R
LT
LT
100
Module with 4.1 mF (width: 100 mm)
Fig. 1-2
Capacitor module mounting locations
Several capacitor modules can be connected in parallel depending on the type
of supply infeed used.
For capacitor modules with 4.1 mF, the charge limit of the supply infeed may not
be exceeded in total.
Reference:
Table 1-2
NC 60
Section, Engineering information
Maximum number of capacitor modules
Infeed unit
Capacitor modules which can be connected
UI 5 kW
None
Monitoring module
without
1
2
UI 10 kW
I/R 16 kW
Module 4.1 mF
1
1
1
Module 20 mF
3
1
0
UI 28 kW
I/R 36–120 kW
Module 4.1 mF
4
4
4
Module 20 mF
3
1
0
 Siemens AG 2001 All Rights reserved
SIMODRIVE 611 Planning Guide (PJ) – Edition 04.2001 (preliminary 21.03.2001)
-5
02.01
Charge times, discharge times, discharge voltage
Before carrying out any commissioning or service work, it should be carefully
checked that the DC link is in a no–voltage condition.
Table 1-3
Charge/discharge times, discharge voltage
Capacitor module
Charge time for
each module
Time for each module to discharge down to
10% of the DC link voltage at 750 V DC
4.1 mF
As for the power
sections
Approx. 24 min
20 mF
Approx. 2 min
Approx. 30 min
If a pulsed resistor is used in the system, to shorten the discharge times, after
opening terminal 48, the DC link can be quickly discharged through terminals
X221:19 and 50 (jumper).
!
Warning
The pulsed resistor modules can only convert a certain amount of the energy
into heat (refer to Table LEERER MERKER). The energy to be converted depends on the voltage.
Caution
In order to avoid damaging the infeed circuit of the NE modules, when energizing terminal X221 terminal 19/50, it must be ensured that terminal 48 of the
NE module is de–energized (electrically isolated from the line supply).
The checkback signal contact of the main NE module contactor must be evaluated to ensure that this has dropped–out (X161 term. 111, term.113, term.
213).
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 Siemens AG 2001 All Rights reserved
SIMODRIVE 611 Planning Guide (PJ) – Edition 04.2001 (preliminary 21.03.2001)