Operating Instructions ACU
19.7.2 Temperature Adjustment
The field-oriented control systems are based on the most precise calculation of the machine model
possible. The rotor time constant is an important machine variable for the calculation. The figure to
be read out via the parameter Act. Rotor Time Constant 227 is calculated from the inductance of
the rotor circuit and the rotor resistance. The dependence of the rotor time constant on the motor
temperature can be taken into account in the case of particularly high precision requirements via a
suitable measurement. Via Operation Mode 465 for the temperature adjustment, you can select
different methods and actual value sources for temperature measurement.
The function is deactivated.
Temperature synchronization
(0 ... 200
°
C => 0 ... 10 V / 0 … 20 mA),
actual temperature value at multifunction input 1
Determination of temperature by frequency inverter via
measurement of the winding resistance without external
temperature measurement
Vectron temp. meas. on
MFI1A
Temperature synchronization; act. temperature value across
analog multi-function input.
(-26.0 °C … 207.8 °C => 0 ... 10 V / 0 … 20 mA)
Operation mode 1 requires an external temperature measurement system which evaluates the
temperature sensor and maps the temperature range from 0...200 °C to an analog voltage or
current signal. Operation Mode 452 of multifunction input MFI1 must be selected accordingly.
Operation mode 4 is available in configurations 210, 211 and 230. When the signals Controller
release and Start clockwise or Start anticlockwise are present, the motor temperature and the rotor
time constant are synchronized by means of the measured winding resistance.
For Operation Mode 11, an optional temperature measurement board from Bonfiglioli Vectron MDS
GmbH is required. This board can be connected to the 20 V power supply on the frequency inverter.
This board converts the temperature to an analog voltage or current signal in a range from -26.0 °C
to 207.8 °C. The resistance of the measuring resistor KTY84/130 to be used is 1000 Ω at a
temperature of 100 °C.
The material used for the rotor winding of the motor is taken into account via the parameter
Temperature Coefficient 466. This value defines the change of the rotor resistance as a function of
the temperature for a certain material of the rotor winding. Typical temperature coefficients are
39%/100 °C for copper and 36%/100 °C for aluminum at a temperature of 20°C.
The temperature characteristic within the software is calculated via the aforementioned temperature
coefficient and the parameter Adjusting Temperature 467. The adjustment temperature enables an
additional optimization of the rotor time constant alongside the parameter Rated Slip Correction
Factor 718.
The synchronization of the rotor time constant as a function of the winding temperature can be
adjusted. The default values should normally be sufficiently precise so that neither an adjustment of
the rotor time constants via the parameter Rated Slip Correction Factor 718 nor an adjustment of
the temperature synchronization via the parameter Temperature Coefficient 466 is necessary. If an
adjustment is necessary, please remember that the rotor time constant is calculated by the guided
commissioning via the machine data. The Adjusting Temperature 467 is to be set to the
temperature at which the optimization of the extended machine data was carried out. The
temperature can be read out via the actual value parameter Winding Temperature 226 and can be
used in the optimization for the parameter.
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