Operating Principle - janitza SVG Series User Manual

SVG 50/100
4.5

Operating principle

In industrial operations, for example in the packaging industry, in welding processes or in
biomass power plants as well, electric motors and pumps with variable frequency drive
technology are being employed more and more commonly. In building engineering as well,
energy efficient lighting, laptops and desktop computers are by now standard equipment.
Power electronics like this, consisting of thyristors and power capacitors, among other
things, have a negative influence on the power quality. Moreover, the behavior in the energy
distribution networks is influenced negatively by network imbalances.
Use of the SVG reduces grid distortions:
• Infinitely variable compensation with inductive and capacitive reactive power
• Reduction of the outage costs, e.g. for frequency converters
• Automatic detection of resonance points
• Individual compensation and dynamic filtering possible
Reduced losses due to 3-level topology: Twice as many IGBTs, lower losses, lower grid
disturbance levels
The SVG detects the current load by means of the external current transformer (CT) in
realtime. After the data analysis, the reactive power change rate is determined and a PMW
signal is sent to the IGBT driver board.
Afterward, an inductive or capacitive compensation current is generated by the converter
technology. Continuous control ensures a more accurate and stable system.
Figure 2-4 Compensation provided by the Janitza SVG
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