Wärtsilä JOVYSTAR
– DELTA 40 – 150kVA BAX 4647E - 9 -
- R
ectifier
The rectifier converts the input AC-voltage into a regulated DC-voltage supplying the
inverter and charging the batteries.
- Inverter
The inverter converts the DC-voltage delivered by the rectifier or by the battery into
an AC-voltage, regulated by Pulse-Width-Modulation. The output of the inverter is
short circuit proof by electronic short-circuit-protection.
With an output current> 100% of rated current or a failure of the inverter the power
supply is switched without interruption on the bypass through the internal static
switch.
- Static Switch
The static bypass consists of a thyristor-switch. It switches the mains over to the
UPS output. During normal operation the inverter output is switched to the UPS out-
put while the bypass is blocked. During overload at the UPS output or an inverter
failure the attached loads will be supplied immediately by the bypass.
- Manual Bypass
The manual bypass feeds the load in case of maintenance or disturbances of the
UPS. The manual bypass is to be used only by qualified personnel under considera-
tion of the described instructions in this manual!
ATTENTION:
A handling error of the internal or (if applicable) any external manual bypass could lead
to a total blackout at the output of the UPS!
2.3.1
Rectifier
The rectifier converts the three phase voltage of the mains into a DC voltage. It uses a 6 pulse fully-controlled thyristors
bridge. The rectifier is designed to supply both the inverter at full load and the battery at the maximum recharge current.
The system offers very low ripple content during the charging cycle.
2.3.1.1
Twelve-Pulse Rectifier (Option)
The twelve-pulse technology is used to reduce the distortion of the current absorbed from the mains (THD) to a value
<12%. This ensures that the rectifier does not distort the mains above these limits. A higher distortion could be an issue
for other loads. It also avoids overloading of cables due to the harmonics circulation. This system is highly recommend-
ed for high power equipment, where the current distortion caused by the rectifier might affect other loads connected to
the mains.
The twelve-pulse rectifier can be provided both, with or without galvanic isolation. It is built by either a choke together
with an isolating transformer or by a transformer with two secondary windings.
twelve-pulse rectifier without galvanic isolation
twelve-pulse rectifier with galvanic isolation
2.3.2
Inverter
It converts the DC-voltage delivered by the rectifier or battery into alternating, stabilized voltage. The control circuitry is
completely digitally. Due to the fast regulation it generates an excellent output sine-wave, which has a very low distortion
even in presence of loads having high crest factor currents.
RCB
Inverter
Battery
Mains
Rectifier
Master
Rectifier
Slave
RCB
Inverter
Battery
Mains
Rectifier
Master
Rectifier
Slave
