I'm currently working through re-creating a simulation I found on YouTube for an integrated PV system with a battery. I found the tutorial here, for reference:
Here's a layout of the Simulink model:
I'm having trouble understanding how the dc-dc bidirectional converter works. I understand on the left-side of the circuit includes a boost converter, and the SimuLink model includes a basic MPPT algorithm script to adjust the duty cycle on the gate of the MOSFET. However, the bidirectional converter is confusing to me. Here is how the pink blocks are determined:
So, the left-side of the circuit (the boost converter), from my understanding, is trying to optimize the voltage and current to extract the maximum power from the PV panel. However ,by setting the voltage reference value at 48 on the battery control, the voltage at the battery is adjusted until it is 48V. The part that confuses me further is the current PI control, and the resulting duty signal. I was under the impression that the purpose of a bidirectional converter as part of a battery controller is to allow current to flow in each direction, but looking at the circuit I'm having trouble figuring out what exactly this section is doing.
I have searched around for bidirectional converter information but most of the materials I find are more advanced. Could someone help me understand how this circuit works, so I can then adjust the loads based on my system and set the correct parameters (e.g., select an appropriate reference voltage)?
Additionally, how does one select the inductance and capacitance values in such a circuit? I am currently using the same ones used in the video, but it's not clear how these should be adjusted if you change the PV array specs or load specs.
Here's a layout of the Simulink model:
I'm having trouble understanding how the dc-dc bidirectional converter works. I understand on the left-side of the circuit includes a boost converter, and the SimuLink model includes a basic MPPT algorithm script to adjust the duty cycle on the gate of the MOSFET. However, the bidirectional converter is confusing to me. Here is how the pink blocks are determined:
So, the left-side of the circuit (the boost converter), from my understanding, is trying to optimize the voltage and current to extract the maximum power from the PV panel. However ,by setting the voltage reference value at 48 on the battery control, the voltage at the battery is adjusted until it is 48V. The part that confuses me further is the current PI control, and the resulting duty signal. I was under the impression that the purpose of a bidirectional converter as part of a battery controller is to allow current to flow in each direction, but looking at the circuit I'm having trouble figuring out what exactly this section is doing.
I have searched around for bidirectional converter information but most of the materials I find are more advanced. Could someone help me understand how this circuit works, so I can then adjust the loads based on my system and set the correct parameters (e.g., select an appropriate reference voltage)?
Additionally, how does one select the inductance and capacitance values in such a circuit? I am currently using the same ones used in the video, but it's not clear how these should be adjusted if you change the PV array specs or load specs.