Simscape FEM-parameterised PMSM error

Hi,

I am attempting to simulate a PMSM drive system using Simscape. Everything works with the ideal PMSM model so i have moved on to implementing the FEM-parameterised model. I have run sweeps in Ansys Maxwell to determine the relevant parameters, and extracted them into Matlab arrays.

I have chosen to paramaterise the motor with the 3d flux linkage option, using d-q currents, the A-phase flux linkage, and the FEM-predicted torque.

My input arrays are as follows:

Id =

  Columns 1 through 13

  -40.0000  -35.7895  -31.5789  -27.3684  -23.1579  -18.9474  -14.7368  -10.5263   -6.3158   -2.1053         0    2.1053    6.3158

  Columns 14 through 21

   10.5263   14.7368   18.9474   23.1579   27.3684   31.5789   35.7895   40.0000

>> Iq

Iq =

  Columns 1 through 13

  -80.0000  -71.5789  -63.1579  -54.7368  -46.3158  -37.8947  -29.4737  -21.0526  -12.6316   -4.2105         0    4.2105   12.6316

  Columns 14 through 21

   21.0526   29.4737   37.8947   46.3158   54.7368   63.1579   71.5789   80.0000

>> theta

theta =

  Columns 1 through 13

         0    1.2500    2.5000    3.7500    5.0000    6.2500    7.5000    8.7500   10.0000   11.2500   12.5000   13.7500   15.0000

  Columns 14 through 25

   16.2500   17.5000   18.7500   20.0000   21.2500   22.5000   23.7500   25.0000   26.2500   27.5000   28.7500   30.0000

The Torque and FluxA are 21x21x25 double matrices.

When attempting to run the simulation, I get the following error:

   Error compiling Simscape network for model InvWithMotorFEA.
Caused by:
['InvWithMotorFEA/Motor']: Direct-axis current vector, iD must include zero and have symmetric positive and negative values.  In ee.electromech.pmsm.fem_motor.fem_motor_dq0_base

As far as I can tell, my Id vector meets the above conditions so I am lost as to what this error means. Of course I can try the other options for parameterising the motor, but it should "just work"

My MATLAB version info is below.

Thanks,

Tim

>> ver
-----------------------------------------------------------------------------------------------------
MATLAB Version: 9.7.0.1216025 (R2019b) Update 1
MATLAB License Number: 573833
Operating System: Microsoft Windows 10 Pro Version 10.0 (Build 18362)
Java Version: Java 1.8.0_202-b08 with Oracle Corporation Java HotSpot(TM) 64-Bit Server VM mixed mode
-----------------------------------------------------------------------------------------------------
MATLAB                                                Version 9.7         (R2019b)
Simulink                                              Version 10.0        (R2019b)
Control System Toolbox                                Version 10.7        (R2019b)
Curve Fitting Toolbox                                 Version 3.5.10      (R2019b)
DSP System Toolbox                                    Version 9.9         (R2019b)
Data Acquisition Toolbox                              Version 4.0.1       (R2019b)
MATLAB Coder                                          Version 4.3         (R2019b)
Optimization Toolbox                                  Version 8.4         (R2019b)
Parallel Computing Toolbox                            Version 7.1         (R2019b)
Powertrain Blockset                                   Version 1.6         (R2019b)
Signal Processing Toolbox                             Version 8.3         (R2019b)
Simscape                                              Version 4.7         (R2019b)
Simscape Electrical                                   Version 7.2         (R2019b)
Simulink Control Design                               Version 5.4         (R2019b)
Statistics and Machine Learning Toolbox               Version 11.6        (R2019b)
Symbolic Math Toolbox                                 Version 8.4         (R2019b)
System Identification Toolbox                         Version 9.11        (R2019b)

Answer 1

[Joel Van Sickel]

Hello Tim,

your id vector needs to look something like this [-40 -20 -10 0 10 20 40]. Your array is mostly symetric, but doesn't contain zero and has a few values that are not symetric.

Regards,

Joel