User Parameters - Allen-Bradley 8720MC-RPS065 User Manual

Chapter 7 Configure Parameters

User Parameters

U.000 DC Bus Voltage Reference
This parameter sets the DC-bus Parameter Range
voltage reference value. The
Default Setting
8720MC-RPS unit controls to
maintain the DC-bus voltage at
Parameter Type
the set value.
Refer also to Parameters
Set the desired DC-bus voltage (V) to this parameter. When the actual DC-bus voltage is lower than the set value, current flows to the direction
of power running, resulting in an increase of voltage. On the contrary, if the actual DC-bus voltage is higher than the set value, current flows to
the regenerative direction, and the voltage drops. But, when the current limit values (U.001 and U.002) are set too low, the DC-bus voltage
might fluctuate because the current to be used for controlling the DC-bus voltage is limited.
When the DC-bus voltage is set too low, control becomes impossible and the DC-bus voltage swings widely. Set the DC-bus voltage to a value
equal to or higher than the peak value of AC input power voltage plus 30V.
When regenerated power enters rapidly due to rapid deceleration of load equipment or other reasons, the DC-bus voltage can rise
instantaneously. To help prevent such rapid change of the DC-bus voltage, adjust the Voltage Control Proportional Gain (F.005).
If the difference between the set values of the DC-bus Voltage Reference and the Bus Overvoltage Detection Level (F.007) is small, bus
overvoltage fault can occur. When a fault occurs, the DC-bus Voltage Reference cannot be set until the fault has been reset.
U.001 FWD Current Limit
This parameter limits current Parameter Range
flowing from the AC input
Default Setting
power to the 8720MC-RPS unit
during operation.
Parameter Type
Refer also to Parameters
Set the FWD current value (flowing in the direction to power running) to be limited as a ratio (%) of the Rated Current (F.002). What is to be
limited is the current value flowing by the PWM switching. It is impossible to limit the current flowing through diodes.
When the set value of the FWD Current Limit is too small, the DC bus voltage might not go up to the set value of the DC-bus Voltage Reference
(U.000).
If the 8720MC-RPS unit operates in the Power Regeneration mode only, set this parameter to 0%. The DC-bus voltage to start power
regeneration is the set value of the DC-bus Voltage Reference (U.000).
When an error occurs, the FWD Current Limit cannot be set until the error has been reset.
U.002 REV Current Limit
This parameter limits current Parameter Range
flowing from the 8720MC-RPS
Default Setting
unit to the AC input power
during operation.
Parameter Type
Refer also to Parameters
Set the REV current value (flowing in the direction to power regeneration) to be limited as a ratio (%) of the Rated Current (F.002). What is to be
limited is the current value flowing by the PWM switching.
When the set value of the REV Current Limit is too small, the DC-bus voltage might not decrease to the set value of the DC-bus Voltage
Reference (U.000), and DC-bus overvoltage error might be detected.
When an error occurs, the FWD Current Limit cannot be set until the error has been reset.
88
User parameters can be adjusted or modified at any time.
275...750V
750V
Configurable only when the unit is normal.
U.001 FWD Current Limit
U.002 REV Current Limit
F.005 Voltage Control Proportional Gain
F.7 Bus Overvoltage Detection Level
F.8 Bus Low Voltage Detection Level
0...150%
150%
Configurable only when the unit is normal.
U.000 DC-bus Voltage Reference
U.002 REV Current Limit
F.002 Rated Current
0...150%
150%
Configurable only when the unit is normal.
U.000 DC-bus Voltage Reference
U.001 FWD Current Limit
F.002 Rated Current
Rockwell Automation Publication 8720MC-RM001K-EN-P - September 2018