Download 3.6 Capacitor module with 4.1 mF or 20 mF

3.6
Capacitor module with 4.1 mF or 20 mF
Description
Capacitor modules are used to increase the DC link capacitance. This allows
brief power failures to be buffered and the braking energy can be stored.
The modules differ as follows:
module with 4.1 mF ––> is used as dynamic energy storage device
module with 20 mF ––> 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 allows an internal fuse failure to be identified.
However, the charge status cannot be reliably monitored.
The 4.1 mF module does not have a pre–charging circuit, and, as it is directly
connected to the DC link, it can absorb dynamic energy and thus be used as a
dynamic energy storage device. The charge limits of the line supply modules
must be taken into account for these modules. The pre–charging for 20 mF modules is realized via an internal pre–charging resistor in order to limit the charging current and to de–couple the module from the central pre–charging. For
this module, no energy can be dynamically absorbed, as the pre–charging resistor limits the charge current. If the power fails, a diode couples this capacitor
battery to the system DC link so that the capacitors buffer the DC link.
Note
The capacitor modules may only be used with the SIMODRIVE 611 supply infeed modules.
The modules are suitable for internal and external cooling.
 Siemens AG 2001 All Rights reserved
SIMODRIVE 611 (PJ)
6SN1197–0AA00 Ausgabe 02.2000 (vorab 30.01.01)
02.01
3.6 Capacitor module with 4.1 mF or 20 mF
LED “READY”
operating display,
is lit from VDC link > 300 V
Capacitor module
100 mm wide
or
300 mm wide
P600
VDC link
M600
PE
Fig. 3-1
Capacitor module
 Siemens AG 2001 All Rights reserved
6SN1197–0AA00 Ausgabe 02.2000 (vorab 30.01.01)
SIMODRIVE 611 (PJ)
02.01
3.6 Capacitor module with 4.1 mF or 20 mF
Technical data
Table 3-1
Technical data of the capacitor modules
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 resistor, the voltage at
the capacitors is only approx.
0.94 x VDC.
The storage capacity in dynamic operation and for regenerative braking is
calculated as follows:
w = ½ x C x (V2DC link max – U2DC link n)
Formula:
Assumptions for the example:
Capacitance of the capacitor battery
C = 4.1 mF
Nominal DC link voltage
VDC link n = 600 V
Max. DC link voltage
VDC link max = 695 V
––> w = ½ x 4.1 x 10–3 F x ((695 V)2 – (600 V)2) = 252 Ws
For the storage capacity of the capacitors when the power fails, the following applies:
w = ½ x C x (V2DC link n – V2DC link min)
Formula:
Assumptions for the example:
Capacitance of the capacitor battery
C = 20 mF
Nominal DC link voltage
VDC link n = 600 V
Max. DC link voltage
VDC link max = 350 V
––> w = ½ x 20 x 10–3 F x ((567 V)2 – (350 V)2) = 1990 Ws
The storage capacity increases to 2904 Ws for a DC link voltage of 680 V.
!
Important
VDC linkmin must be 350 V .
At voltages below 350 V, the switched–mode power supply for the electronics
shuts down.
 Siemens AG 2001 All Rights reserved
SIMODRIVE 611 (PJ)
6SN1197–0AA00 Ausgabe 02.2000 (vorab 30.01.01)
02.01
3.6 Capacitor module with 4.1 mF or 20 mF
The possible buffer time tÜ is calculated using the output DC link power PDC link
as follows:
tÜ = w / PDC link
Dynamic energy
The DC link capacitors should be considered as battery. The capacitance and
the storage capacity are increased by the capacitor module.
The energy flow should be determined in order to evaluate the capacitance required for a specific application.
The energy flow depends on the following:
all of the moved masses (weights) and moments of inertia
velocity, speed (and its change, acceleration, deceleration)
efficiencies, mechanical system, gearbox, motor, inverter (driving/braking)
duration of the buffer time, bypass
DC link voltage and the permissible change, output value upper/lower limit
value.
In practice, often, there is no accurate data available about the mechanical system. If the mechanical system data are determined using approximate/rough
calculations or estimated values, the capacitance of the DC link capcitors required can only be determined by making the appropriate tests during the commissioning phase.
The energy for dynamic operations is obtained as follows:
The following applies for a drive braking or accelerating within time Tv from one
speed/velocity to another:
w = ½ x P x tV
for rotating 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:
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 with braking or accelerating
nMot max [RPM]
Max. speed at the beginning or end of the operation
nMot min [RPM]
Max. speed at the beginning or end of the operation
 Siemens AG 2001 All Rights reserved
6SN1197–0AA00 Ausgabe 02.2000 (vorab 30.01.01)
SIMODRIVE 611 (PJ)
02.01
3.6 Capacitor module with 4.1 mF or 20 mF
vMot max [m/s]
Max. velocity at the beginning or end of the operation
vMot min [m/s]
Min. velocity at the beginning or end of the operation
ηG
Efficiency, overall
ηM
Efficiency, motor
ηWR
Efficiency, inverter
The torque M and the force F are dependent on the moved masses, the load
and the acceleration in the system.
If there is no accurate data about these factors, then generally the nominal/rated
data is used
Engineering information
It is preferable that the capacitor module is mounted at the righthand end of the
system group. It is connected through 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. 3-2
Capacitor module mounting slot
Several capacitor modules can be connected in parallel depending on the line
supply infeed used.
For 4.1 mF capacitor modules, the charging limit of the line supply infeed should
not be exceeded as sum.
Literature:
Table 3-2
NC 60
Section, engineering information
Application possibilities of the capacitor modules
Infeed unit
Capacitor modules which can be connected
UE 5 kW
None
UE 10 kW / I/R 16 kW
max. 1 x 4,1 mF and additional max. 3 x 20 mF
UE 28 kW / I/R 36–120 kW
max. 4 x 4,1 mF and additional max. 3 x 20 mF
 Siemens AG 2001 All Rights reserved
SIMODRIVE 611 (PJ)
6SN1197–0AA00 Ausgabe 02.2000 (vorab 30.01.01)
02.01
3.6 Capacitor module with 4.1 mF or 20 mF
Charge–up, discharge times, discharge voltage
Before carrying–out any commissioning or service work, it should be checked
that the DC link is in a no–voltage condition.
Table 3-3
Charge–up/discharge times, discharge voltage
Capacitor module
Charge–up, each
module
Discharge time, for each module to 10 % of
the DC link voltage at 750 V DC
4.1 mF
As for the power
modules
approx. 24 min
20 mF
approx. 2 min
approx. 30 min
If there is a pulsed resistor in the system, in order to shorten the discharge time
for a DC link fast discharge, the line supply voltage can be disconnected
through terminals X221:19 and 50 (jumpers).
!
Important
In order to avoid damage to the infeed circuit of the NE modules, when energizing 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 (feedback) contact from the main contactor of the NE module
must be evaluated to check that this has really dropped–out (X161 terminal
111, terminal 113, terminal 213).
 Siemens AG 2001 All Rights reserved
6SN1197–0AA00 Ausgabe 02.2000 (vorab 30.01.01)
SIMODRIVE 611 (PJ)