GTS iMAPLA series - Page 36

Issue 08/2013 Page 36
MAPLA- Modular energy supply system for load lifting magnets
iMAPLA system description
Generator and controller
The task of the generator controller is to control the exciter current at
dierent generator speeds so that the voltage emitted by the generator
is constant. The necessary control parameters are rmly programmed
ex works in the form of tables, similar to the characteristic diagram. The
required/permissible exciter currents are set in these parameter tables for
the various speeds (rotational frequencies). The generator controller does not
need aseparate current supply, as it is supplied by the generator.
From iMAPLA series 2013and later, the generator controller is integrated on
the Powerboard. This allows for generator variables to be controlled more
eciently and safely. Modern hydraulic drives or load- and torque proles are
thus more easily controlled.
The optional built-in insulation monitor is assembled in the switch
box. This equipment monitors the generator windings, controller and
the controlled components: load cable and lifting magnet. The system is
operated in electrical separation mode. If the isolation value of one of the
connected components falls below the permissible response value, the
insulation monitor will indicate this, and block the machine from continued
operation as asafety measure. Normally, the lifting magnet is automatically
checked for isolation faults before operating with the built-in option (an
ISO monitor). This function allows the early detection of faults or extensive
damage to magnetic coils. An uncontrolled shut-down due to short circuits is
thus prevented.