In a drive line a power supply XVE2/XVR2 or Converter XCS2/XCD2 needs to supply sufficient power to run all connected drives (DCbus connection).
The DC bus continuous power of a drive PDCcont_axis depends on
The DC bus voltage
Possible connection to a motor (rotative motor, linear motor, without)
Type of usage (motor or generator use)
Application type (typical servo application or typical continuous power application)
Typical Servo ApplicationNo longer lasting movements with constant torque and speed
Often acceleration and deceleration
High overload
Reversing movements
High dynamicsUsage in both speed ranges: close to standstill in working mode; high speed for movement to positions
Typical continuous power application
Longer lasting movements with constant torque and speed
No high dynamics
PDC_cont (supply) >= fG * PDCcont_sum (drive line sum)
PDCcont_sum = sum PDCcont_axis
Following formulas are used for the PDCcont_axis calculation in the ctrlX configurator:
Motor-Drive combination
Drive with rotative motor
Application type
Typical servo application
Type of usage rive
Motor use with power from DC bus
Calculation formula
PDCcont_axis =
(0,5 * M0 * 2 * PI * 0,25 * nmax) / (60 * 1000 * 0,8) =
0,00001636 * M0 * nmax
The reference value is based on a load which results from the effective power calculated with 50% continuous power at an average speed of 25% from max rpm and an average efficiency of 80%.
Motor-Drive combination
Drive with linear motor
Application type
Typical servo application
Type of usage drive
Motor use with power from DC bus
Calculation formula
PDCcont_axis =
(0,5 * F0 * 0,25 * vmax) / (60 * 1000 * 0,7) =
0,00000298 * F0 * vmax
The reference value is based on a load which results from the effective force with 50% continuous standstill force at an average speed of 25% from max speed and an average efficiency of 70%.
Motor-Drive combination
Drive w/o motor
Application type
Typical servo application
Type of usage drive
Motor use with power from DC bus
Calculation formula
PDCcont_axis =
(0,5 * Icont * 0,25 * U_DC * (root 3)) / ((root 2) * 1000 * 0,97) =
0,0001578 * Icont * U_DC
The reference value is based on a load which results from the effective current of 50% continuous output current at an average voltage of 25% from max output voltage and an average efficiency of 97%.
Motor-Drive combination
Drive with rotative motor
Application type
Typical continuous power application
Type of usage drive
Motor use with power from DC bus
Calculation formula
PDCcont_axis =
Maximum(P_Result_cont = f(n)) / 0,85
The reference value is based on the max of the resulting continuous power curve of the motor-drive-combination with an average efficiency (motor and inverter) of 85%.
Motor-Drive combination
Drive with linear motor
Application type
Typical continuous power application
Type of usage drive
Motor use with power from DC bus
Calculation formula
PDCcont_axis =
Maximum(P_Result_cont = f(v)) / 0,75
The reference value is based on the max of the resulting continuous power curve of the motor-drive-combination with an average efficiency (motor and inverter) of 75%.
Motor-Drive combination
Drive w/o motor
Application type
Typical continuous power application
Type of usage drive
Motor use with power from DC bus
Calculation formula
PDCcont_axis =
(Icont * U_DC * (root 3)) / ((root 2) * 1000 * 0,98) =
0,0012497 * Icont * U_DC
The reference value is based on a load which results from the continuous output current at a max output voltage and an average efficiency of 98%.
In single motor-drive combinations (converter) the PDCcont_axis is limited to PDC_cont (supply) of the converter.
Typical DC/DC converter application
Product
DC/DC converter
Calculation formula
PDCcont_axis =
(0,9 * Icont * 0,66 * U_DC) / (1000 * 0,98) =
0.00060612244898 * Icont * U_DC
General
When type of usage drive = generator use with power feeding into DC bus, the PDCcont_axis is a negative value.
Characteristics from formulas
PDC_cont: Continuous DC power with/without choke in kW
PDCcont_sum: DC bus rated power - sum from drive line in kW
PDCcont_axis: DC bus continuous power drive in kW
(in a double axes drive it is the sum of both drive integrated axis)
fG: Simultaneity factor of all connected drives (0..1)
M0: Continuous stand still torque of the motor-drive combination in Nm
F0: Maximum standstill force of the motor-drive combination in N
nmax: Max rpm of the motor-drive combination in rpm
vmax: Maximum speed at Fmax of the motor-drive combination in m/min
U_DC: DC bus voltage in V
Icont: Continuous output current drive when fs = 4 kHz in A
P_Result_cont: Maximum continuous stand still torque of the motor-drive combination in kW