Lenze 8400 User Manual

Lenze · 8400 HighLine · Reference manual · DMS 12.0 EN · 06/2017 · TD23 161
5 Motor control (MCTRL)
5.4 V/f characteristic control (VFCplus)
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
5.4.2.1 Defining the V/f characteristic shape
In principle, four different characteristic shapes can be stipulated:
1. Linear V/f characteristic:
For drives for a constant, speed-independent load torque.
2. Quadratic V/f characteristic:
For drives with a load torque curve which is quadratic or in relation to speed. Quadratic V/f
characteristics are preferred in the case of centrifugal pumps and fan drives.
3. User-definable V/f characteristic (from version 04.00.00 onwards):
For drives that require adaptation of the magnetising current by means of the output speed. The
freely definable V/f characteristic can be used e.g. for operation in conjunction with special
machines such as reluctance motors in order to suppress oscillations at the machine or to
optimise energy consumption.
[5-3] Principle of a linear V/f characteristic (on the left) and a quadratic V/f characteristic (on the right)
4. Linear V/f characteristic with voltage reduction (from version 10.00.00 onwards):
For drives which often work in partial load operation, the energy-saving V/f characteristic
control (VFCplusEco) offers the opportunity to reduce the voltage at low load in order to save
energy. At higher loads, the voltage reduction is cancelled and a linear characteristic is caused.
The V/f characteristic shape is defined by selecting the corresponding motor control mode in
C00006
:
 Tip!
• You can find detailed information on freely definable V/f characteristics in the
subchapter entitled "Defining a user-defined V/f characteristic
". ( 171)
• You can find detailed information on the linear V/f characteristic with voltage reduction
in the chapter entitled "V/f characteristic control - energy-saving (VFCplusEco)
". ( 175)
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V/f characteristic shape Motor control to be selected (C00006)
Linear V/f characteristic 6: VFCplus: V/f linear
Square-law V/f characteristic 8: VFCplus: V/f quadr
User-definable V/f characteristic 10: VFCplus: V/f definable
Linear V/f characteristic with voltage reduction 11: VFCplusEco: V/f energy-saving

Lenze 8400 Specifications

General

Category	DC Drives
Series	8400
Protection class	IP20
Control Type	Vector control
Communication	CANopen, PROFIBUS, Ethernet
Protection Features	Overcurrent, overvoltage, undervoltage, overtemperature
Input Voltage	AC 230/400/480 V