3 optimising the cos/phi controller, Optimising the cos/phi controller, 5motor control (mctrl) – Lenze 8400 User Manual
Page 173
Lenze · 8400 protec HighLine · Reference manual · DMS 3.0 EN · 03/2013 · TD05
173
5
Motor control (MCTRL)
5.5
V/f characteristic control - energy-saving (VFCplusEco)
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5.5.4.2
Adapting the slope limitation for lowering the Eco function
The ramp set in
for voltage reduction serves as slope limitation in order to prevent that
voltage is suddenly applied to the motor when the Eco function is deactivated. Otherwise, the
overvoltage limitation (Imax, Clamp) would be activated.
• This ramp is, depending on the device, pre-initialised to approx. the triple rotor time constant.
An adaptation of this parameter is not required.
When the Eco function is switched off, a quick reaction (high dynamic performance) is required, but
with a low current overshoot and a small torque jump. Thus, the Lenze setting of
is a
compromise regarding the switch-off of the Eco function (voltage reduction = 0).
• To increase the dynamics when switching off the Eco function:
Reduce setting in
(Current compensation actions increase when the Eco function is switched off.)
• In order to reduce current compensation actions when switching off the Eco function:
Increase setting in
(The dynamics when switching off the eco function is reduced)
5.5.4.3
Optimising the cos/phi controller
With the Lenze setting, the cosϕ controller is set such that usually no adaptation is required for all
power ratings and application cases.
Behaviour
Remedy/recommendation
The cosϕ actual value (
) varies greatly.
Reduce gain Vp (
) and reset time Ti (
).
The cosϕ actual value (
) is permanently lower
than the cosϕ setpoint (
Increase gain Vp (
) and reset time Ti (
).