Operating instructions

Commissioning (software)
2.7 Commissioning modes
Control Units CU240S
2-26 Operating Instructions (Compact), 04/2006, A5E00766042B AA
2.7.6 Motor data identification
Motor identification data
The Inverter has a measuring technique which is used to determine the motor parameters:
Equivalent circuit diagram (ECD) ➙ P1910 = 1
Magnetizing characteristic (saturation
curve)
➙ P1910 = 3
For control-related reasons, it is essential that the motor data identification is performed.
Without performing the motor data identification it is only possible to estimated ECD data
using information from the motor rating plate. For example, the stator resistance is extremely
important for the stability of the closed-loop Vector control and for the voltage boost of the V/f
characteristic. The motor data identification routine should be executed, especially if long
feeder cables or if third-party motors are being used.
If the motor data identification routine is being started for the first time, then the following
data is determined, starting from the rating plate data (rated [nominal] data) with P1910 = 1:
• ECD data
• Motor cable resistance
• IGBT on-state voltage and compensation of IGBT gating dead times.
The rating plate data represents the initialization values for the identification. This is the
reason that it is necessary to have the correct input from the rating plate data when
determining the data specified above.
/ ˰6 / ˰5
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Figure 2-7 Equivalent circuit diagram (ECD)
In addition to the ECD data, the motor magnetizing characteristic (see the figure above) can
be determined using the motor data identification (P1910 = 3). If the motor combination is
operated in the field-weakening range (which is above the nominal frequency of the motor),
then this characteristic should be determined, especially when Vector control is being used.
As a result of this magnetizing characteristic, the Inverter can, in the field-weakening range,
accurately calculate the current which is generated in the field and in-turn achieve a higher
torque accuracy.