MOTOR.IMTR

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MOTOR.IMTR

General Information
Type	R/W
Description	Rotor time constant.
Units	Ms
Range	1 to 16,000
Default Value	100
Data Type	Integer
Start Version	M_01-08-00-000

FieldbusA Fieldbus is an industrial network system for real-time distributed control (e.g. CAN or Profibus). It is a way of connecting instruments in a plant design	Index/Subindex	Object Start Version
EtherCATEtherCAT is an open, high-performance Ethernet-based fieldbus system. The development goal of EtherCAT was to apply Ethernet to automation applications which require short data update times (also called cycle times) with low communication jitter (for synchronization purposes) and low hardware costs COE and CANopen	5360h/0	M_01-08-00-000

Description

The rotor time constant is calculated as the ratio between rotor magnetizing inductance Lm and rotor resistance Rr from the following equivalent circuit of an induction machine.

Alternatively, the rotor time constant can be estimated from the rated current, magnetizing current (MOTOR.IMID) and rated slip frequency as follows:

where Is,rms is the rated current, Id,rms is the rated magnetizing current, and ωslip is the rated slip frequency in rad/s.

τ is in seconds for the above formulas. It needs to converted to ms for the MOTOR.IMTR setting:
MOTOR.IMTR(ms) = τ*1000