67/78 SUREWAVE SFC USER MANUAL
11.1.1 System states
11.1.1.1
Stopped
Idle - Ready for start command.
Inhibited - System inhibit is activated, all start commands are blocked, used for Service.
Tripped - System has been tripped, this state is latched, a reset command can attempt to un-
latch it, if the fault is not still present.
11.1.1.2
Not stopped
Wait input grid - Assesses the input AC feed for voltage frequency and stability prior to starting
the rectifiers.
Wait rectifier run -Waits for rectifiers to pre-charge, boost DC bus prior to starting inverters.
Live Bus detect (If Auto start or Coupled start selected) - Determines whether output bus is
suitable for a couple start or if ‘auto start’ is selected determines whether to black start or to
couple start.
Black start
Start inverters - Starts the output inverters with 0 volts as the output setpoint.
Ramp-up - Ramps the voltage up from 0 to the set point and a rate defined in the inter-
nal parameters.
Coupled start
Output PLL lock - Assesses output AC bus for suitable voltage, magnitude and stability
prior to synching.
Sync voltage - Synchronizes internal voltage reference to the output bus.
Sync frequency - Synchronizes internal frequency reference to the output bus.
Sync phase - Synchronizes internal phase reference to the output bus.
Start inverters - Starts inverters a couples with references following the output bus.
RampRef - Transitions the voltage and frequency references to selected reference
sources and set points.
Running
VF Isochronous - Output is set to stiff voltage and frequency
VF Droop - Output is set to V and F droop to share with a parallel source.
PQ Set - Fixed P and Q output, only can be used in VGen mode
External Sync - While the output is running, the output voltage, frequency and phase are
adjusted to match the external measurements. During this transition the droop sharing
is disabled, load enable is forced. When sync command is released the output will transi-
tion back to the selected output mode.
