Nord Drivesystems SK 530P - Energy Efficiency; Figure 15: Energy Efficiency Due to Automatic Flux Optimisation

8 Additional information
BU 0600 en-2319 209
8.6 Energy Efficiency
WARNING
Unexpected movement due to overload
In case of overload of the drive there is a risk that the motor will "break down" (sudden loss of torque).
An overload may be caused e.g. by inadequate dimensioning of the drive unit or by the occurrence of
sudden peak loads. Sudden peak loads may be of a mechanical origin (e.g. blockage) or may be
caused by extremely steep acceleration ramps (P102, P103, P426).
Depending on the type of application, "breakdown" of the motor may cause unexpected movement
(e.g. dropping of loads by lifting equipment).
To prevent any risk, the following must be observed:
• For lifting equipment applications or a
pplications with frequent large load changes, parameter
P219 must remain in the factory setting (100 %).
• Do not inadequately dimension the drive unit, provide adequate overload reserves.
• If necessary, provide fall protection (e.g. for lifting equipment) or equivalent protective measures.
NORD frequency inverters have a low power consumption and are therefore highly efficient. In
addition, with the aid of "Automatic flux optimisation" (Parameter (P219)) the inverter provides a
possibility for increasing the overall efficiency of the drive in certain applications (in particular
applications with partial load).
According to the torque required, the magnetisation current through the frequency inverter or the
motor torque is reduced to the level which is required for the momentary drive power. The resulting
considerable reduction in power consumption, as well as the optimisation of the cos φ factor of the
motor rating in the partial load range contributes to creating optimum conditions both with regard to
energy consumption and mains characteristics.
A parameterisation which is different from the factory setting (Factory setting = 100%) is only
permissible for applications which do not require rapid torque changes. (For details, see Parameter
(P219))
No flux optimisation
With flux optimisation
Motor under full load
Motor under partial load
I
S
= Motor current vector (line current)
I
SD
= Magnetisation current vector (magnetisation current)
I
SQ
= Load current vector (load current)
Figure 15: Energy efficiency due to automatic flux optimisation
I
SD
I
SQ
I
S
U
I
SD
I
SQ
I
S
U
I
SD
I
SQ
I
S
U