TEBEVERT III INVERTER SYSTEM (120 VDC)
07.11.2011
52
028-0009-006
The inverter system supplies a high availability AC current supply to load
equipment that must have an uninterrupted input power supply at all
times. According to the selected operating mode, the inverter output
voltage (inverter priority) or the mains voltage (mains priority) is switched
through to the load equipment by the SBS. In event the priority system
(mains or inverters) should fail, the redundant system is switched with
minimal interruption to the alternate source (within a few milliseconds).
The use of the manual maintenance by-pass switch allows servicing and
maintenance work to be carried out on the inverter system or the
redundant mains without an interruption in the power supply to the load
equipment.
7.2 INVERTER
The function of all the inverters in the system are identical. The applied
DC voltage reaches an intermediate circuit via an input filter. The voltage
in this intermediate circuit is increased to approximately 200V. A high-
frequency transformer separates the voltage between the input and the
output of the inverter. In the bridge of the inverter, the high DC voltage of
the intermediate circuit is transformed into the inverter output voltage of
120 or 230 and a frequency of 50Hz or 60Hz.
In order to obtain a constant sinusoidal output voltage under all operating
conditions, a series of monitoring functions and controls are necessary.
7.2.1 MONITORING OF THE INPUT VOLTAGE
The DC voltage applied to the inverter is monitored for under voltage or
over voltage conditions. The inverter supplies continuous, regulated
output voltage when operated within these limits.
