Rockwell Automation SA3100 Power Module Interface (PMI) Regulator - Manual (Page 30)

2-14 PMI Regulator
Circuitry on the PMI Regulator converts the current feedback from three-phase
sinusoidal currents (Iu, Iw) to DC quadrature torque (Id) and flux (Iq) currents. The
AC-to-DC hardware conversion eliminates the need for the PMI processor software to
do this calculation.
The maximum rated current will result in a 2.5 volt (peak) feedback signal. A 5 volt
feedback signal indicates an instantaneous overcurrent fault (IET). Bit 3 of Drive Fault
register 202/1202 will be set if an overcurrent fault is detected.
The measured RMS motor current feedback is displayed in amps in UDC register
210/1210 (I_FB%) and in counts in register 211/1211 (I_FBN%). The Id (magnetizing
current) component of the current feedback is displayed in counts in register 212/1212
(ID_FBN%). The Iq (torque-producing) component of the current feedback is
displayed in counts in register 213/1213 (IQ_FBN%).
2.2.3.4 Motor Voltage Feedback
Motor voltage feedback is used for the following purposes:
• Diagnostics
• Flux minor loop
The line-to-line motor voltage signals are conditioned by precision analog integrators
and scaled for use in the regulator’s A/D converter. The PMI processor calculates the
flux reference using the integrated motor voltage feedback when the programmer
selects constant power during parameter entry. The measured RMS motor voltage is
scaled in volts and stored in register 209/1209 of the UDC module’s dual port memory.
2.2.3.5 DC Bus Voltage Feedback
DC bus voltage feedback is used for:
• DC bus overvoltage detection
• DC bus undervoltage detection
• DC bus voltage ripple detection
• User’s applications
The system provides DC bus overvoltage protection through both hardware and
software. If the DC bus voltage exceeds the value of the local tunable OVT_E0%, the
system will set bit 0 in the Drive Warning register (register 203/1203). If the power
technology circuit detects that DC bus voltage exceeds 396V for 230 VAC Power
Modules, 789V for 460 VAC Power Modules, or 986V for 575 VAC Power Modules,
the drive is shut down and bit 0 is set in the Drive Fault register (register 202/1202).
Pin 21: U_VOLTS Motor voltage - phase U
Pin 22: V_VOLTS Motor voltage - phase V
Pin 23: W_VOLTS Motor voltage - phase W
Pin 25: NEG_BUS Voltage on the negative side of the DC bus
Pin 26: NEG_CAP Not Applicable
Pin 27: POS_BUS Voltage on the positive side of the DC bus