Siemens SINAMICS PERFECT HARMONY GH180, Function Manual

Page: 194 / 538

7.5 Energy Saver
Improve the Power Factor with Energy Saver Control
Energy saver control reduces motor losses and improves overall efficiency when the demanded
motor load is low. This is accomplished by lowering the flux from rated when the load torque is
not required, thereby lowering the reactive current.
Use of Energy Saver in cell bypass
The control automatically enables the energy saver function when an unbalanced set of cells is
present after cell bypass. Under light loads one or more phases may absorb power from the
motor. To prevent the cell dc-voltage from increasing to a drive trip level, the energy saver
function reduces motor flux so that the motor operates with 70% power factor.
At this operating point, the magnetizing and torque components of motor current are equal, and
all cells deliver real power to the motor. As motor load is increased, the motor flux level is
automatically increased to maintain 70% power factor until rated flux, or maximum possible
flux, is achieved. This function ensures that the cells are delivering real power under all
operating conditions.
Note
Impact of load changes on drive response
The response of the drive to sudden load changes is reduced with lower flux demand.
Setting Energy Saver Control Parameter
Refer to the Flux Control Menu (3100) in Section Options for Stability Menu (3) of
Chapter Parameter Assignment / Addressing for the parameter associated with this function:
• Energy saver min flux (3170)
Adjust this parameter to a value that is less than the flux demand (3150). The value for the
flux demand is typically set to 1.0. Depending on the motor load, the control will reduce
motor flux to a level between the energy saver minimum flux demand and the flux demand.
As motor load increases, the control will increase motor flux until the value set by flux
demand is achieved.
Operating the Control
7.5 Energy Saver
Control Manual
192
Operating Manual, A5E50491925A