Efficient Networks S120 manual Vector control 4.13 Efficiency optimization, Ltvhws

Vector control 4.13 Efficiency optimization

4.13Efficiency optimization

Description

The following can be achieved when optimizing the efficiency using p1580:

●Lower motor losses in the partial load range

●Noise in the motor is minimized

˓VHWS

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LTVHWS

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Figure 4-20 Efficiency optimization

It only makes sense to activate this function if the dynamic response requirements of the speed controller are low (e.g., pump and fan applications).

For p1580 = 100%, the flux in the motor under no-load operating conditions is reduced to half of the setpoint (reference flux) (p1570/2). As soon as load is connected to the drive, the setpoint (reference) flux linearly increases with the load and at approx. r0077 = r0331 * p1570 reaches the setpoint set in p1570.

In the field-weakening range, the final value is reduced by the actual degree of field weakening. The smoothing time (p1582) should be set to approx. 100 to 200 ms. Flux differentiation (see also p1401.1) is automatically deactivated internally following magnetization.

Function diagrams (see SINAMICS S List Manual)

●6722 Field weakening characteristic, Id setpoint (ASM, p0300 = 1)

●6723 Field weakening control, flux control for induction motors (p0300 = 1)

Overview of key parameters (see SINAMICS S List Manual)

●r0077 CO: Current setpoints, torque-generating

●r0331 Motor magnetizing current/short-circuit current (actual)

●p1570 CO: Flux setpoint

●p1580 Efficiency is optimization

Drive Functions	145
Function Manual, (FH1), 07/2007 Edition, 6SL3097-2AB00-0BP4