Simscape "Boost Converter" not functioning as expected.

Hello all,

I am currently trying to utilize a Simscape Boost Converter block to step-up incoming voltage from PV modules having about 7.2V to 16.8V to powerup BLDC motors as shown in the attached picture.

However, whatever I try with various parameter values for the "Boost Converter" block and "DC-DC Voltage Controller" block, both incoming voltage and the outgoing voltage are same to be around 7.2V. I wonder what I am doing wrong in here.

PS: Please refer the following link for the related information.

https://www.mathworks.com/help/physmod/sps/ug/boost-converter-voltage-control.html

https://www.mathworks.com/help/physmod/sps/ref/boostconverter.html

[Antonino Riccobono]

Hi Jung Sunghun,

I have a few recommendations for you concerning the control design procedure you may want to consider:

1. Open-loop analysis with stand-alone boost converter - use an ideal voltage source with value an average of PV voltage and a resistor as output with value R = V*V/P, where V is the expected voltage your motor should work at and P is the rated power
2. Twiking parameters - the boost converter is notorious to be challenging to control in pure voltage mode since the designer must reduce the destabilizing effect of the half-plane zero. You can follow this design procedure.
3. Control design - did you know that you can design your controller directly on the switch-mode converter? This is made possible thanks to a systematic procedure based on Frequency Response Estimation and tools that leverage on the classic control theory available with Simulink Control Design. If you need more info, I advice you to look into this training course: Power Electronics Control Design with Simulink and Simscape.
4. Once the voltage-mode-controlled boost converter is fully tested as standalone, you may replace the ideal voltage source with your PV panel model and the resistive load with your motor.

Hope this helps and good luck!

Cheers,

Antonino

[Jung Sunghun]

Thank you very much for your response.

I replied back to the answer what Mr. Steve Miller wrote since responses are same.

[ayoub reffai]

hello

can you send this model please

Answer 1

[Steve Miller]

As recommended by Antonio above:

1. Open-loop analysis with stand-alone boost converter - use an ideal voltage source with value an average of PV voltage and a resistor as output with value R = V*V/P, where V is the expected voltage your motor should work at and P is the rated power
2. Tweaking parameters - the boost converter is notorious to be challenging to control in pure voltage mode since the designer must reduce the destabilizing effect of the half-plane zero. You can follow this design procedure.
3. Control design - did you know that you can design your controller directly on the switch-mode converter? This is made possible thanks to a systematic procedure based on Frequency Response Estimation and tools that leverage on the classic control theory available with Simulink Control Design. If you need more info, I advice you to look into this training course: Power Electronics Control Design with Simulink and Simscape.
4. Once the voltage-mode-controlled boost converter is fully tested as standalone, you may replace the ideal voltage source with your PV panel model and the resistive load with your motor.

--Steve

[Jung Sunghun]

Thx for the response.

I spent several days since I saw your response but could not complete the step 1 process yet.

The boost converter works well with a required power of 150W (that is, 16.8^2/150) but does not work with more than 200 W for required power from motors (that is, 16.8^2/200).

In my case, the PV panels are required to power about 210W for motors.

[Jung Sunghun]

Finally, I decided to limit the power output to be 170W and it solved every problem.

Thank you very much.