Komatsu 830E-AC Shop Manual page 413

DC Link State
Power is provided to the inverters and motors via the
DC link. The DC link has two associated states:
powered and unpowered. The following defines the
conditions necessary to establish each state, as well
as the transitional conditions between the two states:
Powering the DC Link: The PSC software will
attempt to power the DC link (command the system
configuration defined below) if all of the following
conditions are true:
• Event restrictions do not prohibit power on the
DC link.
• The system is in Test state and any initiated
testing is complete.
• The engine is running.
• The gate drive power converters have been
enabled.
• Neither inverter is requesting that a low voltage
test be run.
In attempting to power the DC link, the PSC software
will establish the necessary system configuration as
follows:
1. GF is closed and GFR is picked up.
2. AFSE is enabled.
3. Alternator field reference is commanded so that
the desired DC link voltage or three-phase
voltage is maintained.
4. RP contactors open.
5. Chopper turn-on voltage is set above 600 volts.
NOTE: Before the AFSE is allowed to output firing
pulses, the RP contactors will be commanded to
open and the GF contactor will be verified to be
closed. The AFSE will not output firing pulses if it is
disabled, if GFR is dropped out, or if the alternator
reference signal is 0.
E02020 10/06
De-Powering the DC Link: The PSC software will
attempt to de-power the DC link (command the
system configuration defined below) if the system is
in Test or Ready state and any of the following
conditions are true:
To accomplish this, the PSC software will establish
the necessary system configuration as follows:
Electrical Propulsion System Components
• Event restrictions prohibit power on the DC link.
• The system is preparing to transition to Startup/
Shutdown state for the purpose of shutdown (all
the non-link-related conditions
Shutdown state have been satisfied).
• The system is preparing to transition to Rest
state (all the non-link-related conditions for Rest
state have been satisfied).
• The engine is being shut down.
1. Alternator field reference isset to zero.
2. AFSE is disabled.
3. GF is open and GFR is dropped out.
4. Chopper turn-on voltage is set below 600 volts.
5. RP2 is closed.
for Startup/
E2-29