MATLAB: Should I use rated or locked rotor impedance values with the Induction Machine Squirrel Cage block

cageimpedanceinductionlockedmachineratedrotorSimscape Electricalsquirrel

I am interested in using the Induction Machine Squirrel Cage block from the Simscape Electrical library in my simulation. The induction motor I want to simulate includes both rated and locked rotor impedance values for each of the block parameters in the "Impedances" tab. Which impedance value should I use?

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The Induction Machine Squirrel Cage block should be used with rated impedance values.

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MATLAB: Is there a DC permanent magnet motor block in SimPowerSystems 3.1 (R14)

This enhancement has been incorporated in Release 2010a (R2010a).

For previous product releases, the ability to use a DC permanent magnet motor block directly from a library is not available in SimPowerSystems.

To work around this issue:

You can use and modify the DC machine block to model a DC motor with permanent magnets. You can copy a DC Machine block (DC motor) in a new model, and then break the link to the library.

Note that the motor has two sets of electrical terminals: the armature (A+ A-) and the field armature (F+ F-). For the case of a permanent magnet DC motor, the field armature does not exist. Look under the mask of the block, note the Rf Lf and the iF current measurement block. In a permanent magnet model, the magnets provide a constant 'if' current to the model. Remove the F+ and F- terminals and all the blocks between them, then use a Constant block to feed the mechanical input 'if'. The constant value depends on the type of magnet used in the DC motor. The knowledge about the constant value and the type of magnet used will have to be obtained from the manufacturer sheet of the machine.

MATLAB: Is it possible to calculate the Flux induced by magnets [Wb] value from the Torque Constant and Back Induced Voltage for the SimPowerSystems block Permanent Magnet Synchronous Mode

The Flux induced by magnets [Wb] parameters can calculated by the formula:

 flux = 2*kt/(3*p)
 with
 kt = torque constant (Nm /A rms)
 p = number of pole pairs.

Alternatively, it can be calculated with the voltage gradient

 flux = ke * sqrt(3)/(100*pi*p)
 with
 ke = voltage gradient (V peak Line-Line)
 p = number of pole pairs.

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Related Solutions

MATLAB: Is there a DC permanent magnet motor block in SimPowerSystems 3.1 (R14)

MATLAB: Is it possible to calculate the Flux induced by magnets [Wb] value from the Torque Constant and Back Induced Voltage for the SimPowerSystems block Permanent Magnet Synchronous Mode

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