BN 09 2671/01/01
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The mains voltage is applied to the primary winding of the power transformer via the standard mains input breaker.
The rectifier is then in service, provided no fault has been detected and/or stored by the monitoring systems.
The power converter consisting of a full thyristor bridge rectifies the transformer secondary voltage.
The rectifier current is smoothed by an inductor integrated inside the transformer and the voltage is filtered by
capacitors.
The rectifier current is sensed across a rectifier shunt. A blocking diode (option) is connected to the rectifier output
and is used to isolate a faulty unit while the rectifiers are in the parallel configuration.
The GCAU control board is supplied either by the auxiliary secondary winding of the transformer or from the battery.
The GCAU board controls the power converter from internal references (which depend on the battery type and the
current charge mode) to regulate the rectifier output voltage and/or current. There is a protective fuse inserted in
the positive output polarity of the rectifier.
The battery current is sensed across a battery shunt
(option)
.
A temperature sensor senses the battery temperature and compensates the rectifier output voltage according to
the temperature
(option)
.
7.4 "GCAU" GENERIC CONTROL AND ALARM
UNIT (A1)
This board has two dedicated microcontrollers, memories for the microcontroller and all necessary analog interface
circuits to measure and control. The board is installed inside the cabinet, on charger mounting plate.
The board consists of two major functional blocks:
- an
analog
block providing the following main functions:
. analog signal (current and voltage) matching,
. synchronisation (in case of single phase),
. power converter thyristor gate firing by electrically isolated pulses (for single-phase only),
. electronic circuits power supply ,
. analog control signal 0-10V.
- a
digital
block with two micro controllers providing the following main functions:
. analog input (voltage, current and temperature) measurement,
. digital input/output monitoring,
. system operating and monitoring sequences controlled by a program stored in memory,
. setpoint (reference) generation for the analog regulators,
. full digital control algorithm (separate micro controller),
. serial communication for remote monitoring/programming,
. serial communication for display unit,
. on- board Flash memory and EEPROM.
The fuses for GCAU and TPC boards protection are integrated on the charger mounting plate.
7.5 "TPC" THREE- PHASE CONTROL
BOARD (A2)
The board is controlled via a link cable connected to the GCAU board.
The TPC has all necessary electronics to synchronise to the secondary transformer voltage and to control the
thyristors.
The board is phase insensitive meaning it will operate with all possible phase rotations.
