Rockwell Automation 2364P Parallel DC Bus Supply Config. - Manual (Page 197)

Publication 2364P-5.01 December 1999
Setting Up the Parallel Configuration 16-7
Advanced Startup Procedure This advanced startup procedure may be performed to set the RGU
for optimum performance. A HIM, GPT, or other programming
device will be required to complete the procedure below.
Id Current Command [P102]
The Id current command determines the amount of reactive current that the RGU should allow. Typically,
this value should be set to 0.0% (default).
For applications requiring reactive current, P102 can be adjusted from 60% lagging to -40% leading power
factor. If a non-zero value is given as the Id current command, the RGU will run at that percentage of
reactive current from the rated AC line current, even if the RGU is unloaded.
Note that reactive current in the RGU takes away from the active, work-producing current (Iq), and reduces
efficiency of the RGU. (P102 does not function in slave RGUs.)
Example
If an RGU is set with a -40% leading reactive current (Id), the available active current (Iq) could be
determined in the formula (%Id² + %Iq² = %I
total ²).
%Iq =
√
(100%)² - (40%)² = 92% (Example Only) [%I total =100%]
At full load, the total current would be 100%, but the active (work-producing) current would only be 92%.
Since P102 only determines the amount of reactive current that the RGU will produce (not regarding the
load), the RGU would operate at a power factor of 0 (at no load) and increase to a power factor of -0.92
(at full load).
Voltage Mode Select [P123]
This parameter determines the voltage command that should be supplied to the regulator. The default,
‘Bus Ref Auto’, selects the value from the Bus Reference Automatic (P129), which is calculated by:
P129 = (Measured AC Line Voltage) x
√
2 x 1.042 i.e. P129 = 460 x
√
2 x 1.042 = 678V DC
If there is an NRU in the configuration, the master RGU must be set to Bus Ref Auto.
To maintain the bus at a constant voltage, independent of the AC line voltage, the ‘Aux Volt Cmd’ or
‘Bus Volt Cmd’ may be selected. However, note that the RGU will not operate at 1.0 power factor if the
the specified voltage is less than the peak of the AC line (AC line voltage x
√
2).
For example, if an RGU is supplied with 460V AC input, but the DC voltage command is set to 640V DC, the
RGU would be forced to operate with a some lagging current, which would reduce the efficiency of the RGU.
In this case, a voltage command greater than 651V DC (460 x
√
2) would be a better choice.
Current Loop Bandwidth [P198]
The current loop bandwidth determines the dynamic behavior of the current loop. The current loop
becomes more responsive and is able to track faster as the bandwidth is increased. However, note that
system limitations and excessive noise may adversely affect the performance of the RGU if the bandwidth is
set too high.
Typically, acceptable bandwidth settings are in the range of 800-1000 rad/s (for J or K-code RGUs) or in the
range of 600-900rad/s (for L, M, or N-code RGUs). A current bandwidth of 800 rad/s is recommended. In
any case, both master and slave RGUs must have the same setting.
Set master and slave RGUs with same value.
Current Loop Damping [P199]
The current loop damping determines the dynamic behavior of the current loop. This damping influences
the amount of overshoot the current loop will exhibit during a transient. Typically, this value should be set
to 100%.
Set master and slave RGUs with same value.
0 . 0 %
I d C o m m a n d
B u s R e f A u t o
V o l t M o d e S e l
8 0 0 r a d / s
D S P B a n d w i d t h
1 0 0 %
D S P D a m p i n g