Selection Of The Inverter - HEIDENHAIN TNC 410 M Technical Manual

3.4 Selection of the Inverter

Procedure
Mathematical
formulas for
calculation
Data
DC-link power P
DC
Selection of the
power supply unit or
examination of the
compact inverter
3 – 10
Modular inverter:
The power modules were already selected together with the axis motors. The
power supply unit must still be selected.
Calculation of the dc-link power
Selecting the power supply unit
Compact inverter:
The number of axes and the requirement for current determine the compact
inverter. It remains to be examined whether the dc-link power of the selected
compact inverter suffices.
Formulas
Σ
P
P
NA
NS
-------------- -
P = -------- - +
η
η
DC
A
S
≤
P P
DC NU
HEIDENHAIN Technical Manual for Inverter Systems and Motors
Variable
P : Power rating of the spindle motor
NS
[W]
η
: Efficiency of the spindle motor [-]
⋅
S
F
Mratio
ΣP
: Sum of the power ratings of the
NA
axis motors [W]
η
: Efficiency of the feed motors [-],
A
unless indicated otherwise η
F
Mratio
power of the feed motors.
P : DC-link power [W]
DC
P : Rated power of the power supply
NU
unit or the compact inverter [W]
: Ratio of mean power to rated
= 1
A