modeling a solenoid coil

Hello All,

I am trying to model a solenoid in simscape using the blocks from simscape electrical, mechanical and physical signal blocks. The equation that I have considered is

V = i*R + L*di/dt + i*(dL/dt)

V = voltage, i = current through the solenoid, R = resistance of the coil, L = inductance, dL/dt = dL/dx*dx/dt rate of change of inductance with respect to change in plunger position.

I will be using the force - stroke characteristic data to evaluate dL/dx.

When I rearrange the above equation and solving for i, we get

i = (1/L) * int ( V - (i*R) - i*(dL/dx)*(dx/dt))

When I impliment this particular equation using physical signal blocks and try to simulate it, I am getting the following error:

I kindly request you to guide me to overcome this error.

Thanks and Regards,

Goutham Sajja

Answer 1

[Juan Sagarduy]

Hello Goutham

I think you will find creating a Simscape component a better solution. Then, you can write the equations textually.

See link to give u a hint: https://se.mathworks.com/videos/simscape-language-electronic-example-73114.html

Best Regards Juan

[Goutham Sajja]

Hello Juan,

I thank you for your reply.

I did try to create a custom Simscape component. I considered adding an additional input to the PS Subtract block. But when I try to simulate it, I am getting the following error:

Kindly advice,

Thanks

Goutham Sajja

[Juan Sagarduy]

Hello Goutham

I attach a ssc implementation of a dynamic inductance, pretty much as described in the snapshot. You will see how this is done, I use the inductor in the Foundation Library as a base to create the ssc in the attachment.

We have a 1-day course on Simscape that you may find interesting to attend and give you a rounded insight on physical network modeling. See link:

Modeling Physical Systems with Simscape | MATLAB and Simulink Training (mathworks.com)

Best of Luck

Juan