Hi,
I am trying to determine the proper operation of the boost-converter in the TI renewable energy developer's kit.
I have a few questions and would really appreciate your assistance to determine if the board is faulty.
I like to mention that while performing my tests, I always kept these three switches fixed as follows: SW1 ON, SW2 OFF and SW3 OFF.
1) Although I am able to operate in both open and close loop operation mode, i am having trouble validating the measurements obtained from the GUI with the theoretical values. The voltages obtained at the output of the boost-converter (Vdcbus) were higher than what is expected. is that normal?
For instance, with 9Vdc at J2 and boost_cmd = 1899 (with 280x MCU), I read Vdcbus = 10.5V whereas i expect 9.45V.
2) I would like to know what the output voltage of the boost-converter at the cathode of D4 (Vdcbus) should initially be, when we start running the code where we have SW4 OFF and the variable "start = 0". I am having ~8V at Vdcbus, which seems very strange.
3) I would also like to know what should be the expected value of "Vdcbus" when we turn SW4 ON and set the variable "start = 1". for both cases where we have a DC supply "VdcIn = 0V" and "VdcIn = 9Vdc" as the main input source (connected at J2).
4) Lastly, I would like to confirm my method of calculating the duty cycle for the boost converter.
Since I am using a 280x family of MCU, the boost_cmd varies between 1999 to 0, for 100% and 0% duty cycle, respectively. Can I say if I set boost_cmd to 1899 that the duty cycle is (1 - 1899/1999) *100% = 5.00%?
Cheers,