Rockwell Automation 2364F Regenerative DC Bus Supply Unit (RGU) - Manual (Page 92)

Publication 2364F-5.01– October 2003
8-8 Setting Up Your RGU
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.
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%.
Voltage Loop Bandwidth [P205]
The voltage loop bandwidth determines the dynamic behavior of the voltage loop. The voltage 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.
If the RGU is supplying a single inverter, a voltage loop bandwidth of 200 rad/s is recommended (300 rad/s
maximum). If the RGU is supplying multiple inverters, the voltage loop bandwidth should be calculated using
the following formula:
Example
An RGU (catalog number 2364FA-MNB) is connected to a 1336 FORCE (100HP), 1336 PLUS (150HP), and
SA3100 (150HP).
The catalog number (2364FA-MNB) indicates the unit is a 460V AC M-code RGU. The internal capacitance
for this unit is 2400 uf/10 (as shown in Appendix D, P204). The total external capacitance for the inverters is
3300 uf/10 (which will become the value for P203). Using the formula, we can determine the appropriate
value for the voltage loop bandwidth (P205):.
Voltage Loop Damping [P206]
The Voltage Loop Damping (P206) also determines the dynamic behavior of the voltage loop. This damping
influences the amount of overshoot the voltage loop will exhibit during a transient. Typically, this value should
be set to 100%.
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
P205 =
200 x P204
P203 + P204
2 0 0 r a d / s
B u s V o l t B W
P205 =
200 x 3300
2400 + 3300
= 115 rad/s (Example Only)
1 0 0 %
B u s V o l t D a m p i n g