Rockwell Automation 7000A PowerFlex Medium Voltage Drive (A-Frame) - Classic Control - Manual (Page 293)

Functional Description 5-25
7000 “A” Frame 7000A-UM150F-EN-P – June 2013
A T T E N T I O N A T T E N T I O N Application of medium voltage to the drive
input or output when it is operating in gate test
mode may cause severe damage to the drive.
To test the line converter and to tune the dc link current regulator and
the line commutating impedance, the drive Operating Mode is
selected as DC Current. In this test mode, the line converter
operates normally, but the machine converter gating is modified to
gate both the positive and negative legs in the same phase in order to
short-circuit the dc link current through the machine converter. The
short circuit current is slowly rotated among the three phases with
overlap between phases to ensure that an open circuit does not occur
during commutation. There is no current in the motor and the output
contactor (if installed in the drive) is opened). The dc current
command is set equal to the value specified by parameter Idc
Command Test (119) in the Current Control group. In this test mode
the line converter firing angle Alpha Line (327) will be close to 90
degrees. This is because it takes very small dc voltage to build
current in a shorted dc link.
Setting Operating Mode to System Test selects the system test mode.
This mode is used to test the drive as a system, including interfaces
with external devices such as programmable controllers, without
applying power to the drive or motor. The drive behaves as if it was
running normally but device gating disabled. Since the input, output,
and bypass contactors operate normally in this mode, it must be
ensured that the drive and motor are isolated from medium voltage.
If the drive detects medium voltage in this test mode, a fault MV in
SystemTest is issued and the input contactor is opened.
A T T E N T I O N A T T E N T I O N It is the responsibility of the operator to ensure
that the drive and motor are isolated from
medium voltage when the drive is operating in
system test mode with the input, output, and
bypass contactors closed.
Setting Operating Mode to Open Circuit, selects the open circuit test
mode. This mode is used to test the drives at rated output voltage
and frequency without connecting it to a motor. In open circuit test
mode, ac current sufficient to produce rated voltage at the drive
output is forced through the output filter capacitors. When the drive
is started in this mode, it ramps up to rated frequency and
synchronizes its output voltage with the line voltage. The current
reference is set to a value that will produce voltage at the drive
output set by the parameter Flx Cmd Base Spd (100).