Boost Converter Issue: Voltage Decreasing Instead of Increasing in Simscape Solar Model

I am trying to design a boost converter in Simscape as part of a solar plant model. The goal is to set the voltage to 400 V DC for grid integration at 50 Hz before it enters the inverter. However, instead of raising the voltage, the boost converter lowers it.

I have modelled the PV system with the solar cell element (18x2 solar cells) as the input, and the step-up converter is supposed to increase the voltage. The duty cycle is only set to 0.6 here, for example, because I want to see what effect this has, but it has none.

Answer 1

[MULI]

Hi @Israfil-Cihan,

I understand that your boost converter is lowering the voltage instead of increasing it.

To troubleshoot and resolve the issue, you can check the following aspects of your model:

• For a duty cycle of 0.6, the theoretical output voltage of a boost converter should be 2.5 times the input voltage.
• If you observe no change in the output voltage, verify that the PWM signal is correctly modulating the gate of the MOSFET.
• Ensure the PV array provides sufficient voltage and current to the boost converter for it to function effectively.
• The input voltage from the PV array must be high enough to achieve the desired step-up to 400 V DC.

You may refer to this “Grid-connected PV array with DC-DC boost converter model”, which demonstrates how a boost converter is effectively used in a grid-connected PV system: https://www.mathworks.com/matlabcentral/fileexchange/34752-grid-connected-pv-array