Rockwell Automation 2364P Parallel DC Bus Supply Config. - Manual (Page 22)

Publication 2364P-5.01 December 1999
1-10 Theory of Operation
If there are two RGUs in the configuration, each RGU will supply up
to 10% of its rated motoring current. If the load is in this 10%, the
RGUs will regulate the bus voltage. The master RGU will evaluate
the bus voltage, and will determine the current required to maintain
the nominal bus voltage (1.52 times the line voltage). The master
RGU will send a current command to the slave RGU, and both RGUs
will begin switching their IGBTs to provide the proper motoring or
regenerative current.
Figure 1.16
NRU With Two RGUs–Motoring
Figure 1.17
NRU With Two RGUs–Regenerating
NRU
3-Phase
AC Line
1.52 x AC Line
Voltage
RGU RGU
RGU-to-RGU
Communications
Current
(Up to 10% of
the RGU rated
amperes)
Current
(Up to 10% of
RGU rated
amperes)
No
Current
v
V
Motoring - Up to 10% of RGU Rated Amperes
NRU
3-Phase
AC Line
1.35 x AC Line
Voltage
RGU RGU
RGU-to-RGU
Communications
Current
(10% of the
RGU rated
amperes)
v
V
Motoring - Over 10% of RGU Rated Amperes
Current
(10% of
RGU rated
amperes)
Current
(Up to 100% of
the NRU rated
amperes)
NRU
3-Phase
AC Line
1.52 x AC Line
Voltage
RGU RGU
RGU-to-RGU
Communications
Current
(Up to 100% of
the RGU rated
amperes)
Current
(Up to 100%
of RGU rated
amperes)
No
Current
v
V