SIEMENS
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Siemens D 31 · 2015
2
Highlights
Efficient Infeed Technology
■
Overview
Regenerative feedback with SINAMICS G120 and
SINAMICS G120D
With its Efficient Infeed Technology, Siemens AG is setting a
global standard for drives of compact design. The technology
applied is a world first and provides regenerative feedback
capability in smaller, lighter and much lower-cost inverter units.
Available drives with Efficient Infeed Technology
The following drives are equipped with Efficient Infeed Technology:
•
SINAMICS G120 (integrated in PM250 Power Modules)
• SINAMICS G120D
•
SIMATIC ET200pro FC-2 (available soon)
Potential savings thanks to Efficient Infeed Technology
The table below shows the advantages of the technology as
compared to conventional 2-quadrant inverters.
Three technical criteria are of particular significance:
•
Regenerative feedback
- 100 % braking power is fed back, allowing continuous
braking. This is possible using braking resistors which take
up a lot of space and are expensive.
- A braking resistor does not need to be configured.
- No need for installation, thermal monitoring, etc. of external
components.
•
Minimal reactive power distortion
-
Low reactive power distortion thanks to current consumption
that is almost block-shaped, the power factor
λ
is virtually
0.9. The transformer throughput rating is therefore lower than
that required for inverters with a standard DC link.
- In order to achieve such a low harmonic content (line
harmonics) for an inverter with a conventional DC link, a
line reactor with a
u
K
= 6 % is required.
- This results in approx. 22 % lower current consumption
which corresponds to approximately 40 % lower losses in the
supply system.
- The load on the power supply system is therefore reduced.
•
Improved offset factor cos
ϕ
- Slightly capacitive at input
≅
0.95 capacitive.
- Compensates the reactive power of motors and other
inductive loads on the same supply.
-
The power draw of the entire system is reduced. In a system
comprising one inverter with motor and another motor on the
same supply, the total power draw is reduced by up to 12 %.
Line supply conditions
Inverters with Efficient Infeed Technology have a much lower
harmonic content (and therefore lower reactive current compo-
nent) than a standard inverter. The harmonics up to and includ-
ing the 11th are significantly lower than specified in the relevant
standard. These relevant harmonics are less than half the
magnitude stipulated by the relevant standard (EN 61000-3-12).
Permissible ratio between network short-circuit power
S
K_line
and inverter apparent power
S
inverter
:
S
K_line
≥
100 ×
S
inverter
according to
u
K
≤
1 %
■
Benefits
•
Continuous braking with 100 % braking power
•
Energy savings through regenerative feedback with motor
operating in generator mode
•
Omission of braking resistor, line reactor and brake chopper
•
No costly configuration of the braking resistors and no
time-consuming cabling
•
Requires considerably less space than a conventional
compact inverter
•
Up to 22 % less power infeed
•
No additional heat generated during braking
•
Cost savings
•
Space savings
G_D011_EN_00182a
Standard
Technology
Efficient Infeed
Technology
Line reactor
Braking resistor
Configuration
overhead
Generated
harmonics
Heat generated
when braking
Required
Required
Standard
Standard
Yes
Not
required
Not
required
Low
Minimal
No
Power infeed
Power consumption
Energy efficiency
Installation outlay
Standard
Standard
Standard
Standard
Reduced
Lower
Good
Low
© Siemens AG 2014