Wärtsilä JOVYSTAR COMPACT L
BAX 5624
- 41 -
11 General UPS Description
11.1 Typology
The UPS described in this manual is on-line, double conversion; the inverter included in the UPS
always supplies energy to the load, whether mains is available or not (according to the battery
autonomy time).
This configuration guarantees the best service to the User, as it supplies clean power uninterruptedly,
ensuring voltage and frequency stabilization at nominal value. Thanks to the double conversion, it
makes the load completely immune from micro-interruptions and from excessive mains variations, and
prevents damage to critical loads (Computer - Instrumentation - Scientific equipment etc.).
Output voltage present
The line connected to the UPS output is energized even during mains failure, therefore in
compliance with the prescriptions of IEC EN62040-1-2, the installer will have to identify the line
or the plugs supplied by the UPS making the User aware of this fact.
Picture 25 – Block diagram
The UPS uses IGBT technology with a high switching frequency in order to allow a low distortion of
the current re-injected into the supply line, as well as high quality and stability of output voltage. The
components used assure high reliability, very high efficiency and maintenance easiness.
11.2 System Description
11.2.1 Rectifier
It converts the three-phase voltage of the AC mains into continuous DC voltage.
It uses a three-phase fully-controlled IGBT bridge with a low harmonic absorption.
The control electronics uses a 32 bit µP of latest generation that allows to reduce the distortion of the
current absorbed by mains (THDi) to less than 3%. This ensures that the rectifier does not distort the
supply mains, with regard to the other loads. It also avoids cable overheating due to the harmonics
circulation.
The rectifier is so sized as to supply the inverter at full load and the battery at the maximum charging
current.
