ABB PQFS Installation, Operation And Maintenance Instructions page 157

Fault message
DC undervoltage (SW)
IGBT check cooling
IGBT permanent
Cause
The DC software undervoltage
protection has been triggered.
The software IGBT
temperature protection has
been triggered.
The IGBT module reports
an error that cannot be
cleared by the system. This
error can be due to peak
overcurrent, too low control
voltage for the IGBT drivers
or IGBT module failure.
Manual Power Quality Filter PQFS ç Troubleshooting guide 157
What to do
– Check the connection between the
DC voltage measurement
connectors (P6-5 and P6-7) and
the DC capacitors.
– Check flat cable connections
between the Control Board and the
IGBT module.
– Analyze network voltage stability
(amplitude and phase).
– Disable reactive power
compensation and balancing
options to see if the problem
persists.
– Check the main contactor and its
control signal.
– Check the cooling of the filter
system (fans and air flow,
heatsink).
– Check the cooling of the location
where the filter is installed (air
conditioning system etc.)
– Ensure that the correct derating
factor is applied noting the ambient
temperature and altitude.
– Identify unit for which the red LED
(3) is on.
– Inspect the corresponding IGBT
module (bridge and DC capacitors)
for visual traces of damage. If they
are present, exchange the IGBT
module.
– Verify flat cable connection
between the Control board and the
IGBTs.
– Ensure that the Control board
power supply is around 24 V. If
significantly lower, check the 24 V
power supply and the wiring
between this supply and the
Control board.