how can we plot the voltage trajectory of pmsm motor , when we have vd and vq data from simulink?What kind of plot is this?

paper : Voltage Control Technique for the Extension of DC-Link Voltage Utilization of Finite-Speed SPMSM Drives

Answer 1

[MULI]

Hi Deepak,

To plot the voltage trajectory of a Permanent Magnet Synchronous Motor (PMSM) using the data from Simulink, you can follow below steps

• Export the data from Simulink using “To Workspace” block to the MATLAB workspace and you can refer to the below link for more information on this block: https://www.mathworks.com/help/simulink/slref/toworkspace.html
• Once you have the Vd and Vq data in the MATLAB workspace, you can use the `plot` function to create the trajectory plot.
• The plot represents the trajectory of the voltage vector in the dq plane. The trajectory often appears as spirals or loops, indicating how the motor's voltage vector changes over time.
• The spiral shape is due to the motor's dynamic response under varying loads or control inputs.

Answer 2

[Raghunath Rachabattuni]

Hi,

PMSM has multiple characteristic curves usually drawn on id-iq plane (Currnet limit curve, voltage limit curve, mtpa curve, mtpv curve, and constant torque curve). Few curves are plotted in vd-vq plane too (the vd and vq of the motor as measured during a simulation or dyno test). This curve could be useful in understanding the voltage constraint behavior of the control under investigation to see if the constraint is satisfied or not. The voltage limit constraint that is plotted in vd-vq plane is an ellipse (for a fixed speed) and an ellipse when plotted in id-iq plane.

However it is a general practice to observe how the constraints are satisfied during the machine operation in id-iq plane.

The following page gives more information about the constraint curves.

PMSM Constraint Curves and Their Application - MATLAB & Simulink Example