IMPLEMENTATION OF SOLAR MPPT METHOD

[gomugomu]

can i know how to implement variable size incremental conductance method for tracking my mppt.

Also define hardware that is to be used (i think CRIO should be used).

how to connect the pv panel to a crio or i need some other hardware..

and last how to control it.(the diagram on the control panel the block diagram)

i mean to say that the mppt method can be implemented using labview blocks or i have to write the coding in mathscript or something like that. i just want to get all these things clear..of how to perform a mppt method (harware +software)...and after that how to give the desired pulses to a boost converter(by using some sort of hardware?).

[Annaa01]

hello,

I'am working on the same project.

Please tell me if you found the answers to your questions?

Thankk you very much

[RTSLVU]

Well I am no MPPT algorithm expert, but I have been working with MPPT charge controllers for some time. MPPT chargers are in essence PWM but usually can also boost besides buck the array voltage. 

In a nutshell you "sweep" the array, loading it from Voc to Isc keeping track of the power and storing the settings that gave the maximum power. Then you go back to Voc and slowly ramp up to that point. 

Sweep the array at regular intervals (like once or twice an hour) to pick up changes caused by movement of the sun and sweep anytime power changes by say 10% for dynamic changes in cloud cover.  If you want to be fancy program a "small sweep" for the dynamic changes instead of doing the full sweep every time a cloud passes over.

As for the hardware you are on your own, sorry...

[Ananthkumar]

Hardware

For transformerless booster, pls refer the below link,

http://www.vincotech.com/fileadmin/downloads/power/ApplicationNotes/AN200912Designconceptsinglephase...

Functionally two main blocks,

1. Control block – measures feedback signals, executes control algorithm, generate PWM pulses
2. Power block – triggering mosfet for buck, inductors, DC Cap

Software

For better Mppt tracking, at low power start with constant voltage method,

Read Voc and set reference as 80% of Voc.

When power is enough to measure, start Mppt tracking with incremental conductance algorithm.

PV Fast sweep

Scanning the PV voltage from Vpv_min to Vpv_max. As it compromises the Mppt efficiency, choose appropriate interval to meet the static Mppt efficiency as rated in EN50530.

 courtesy: https://in.mathworks.com/discovery/mppt-algorithm.html

Requisite for control block functionality implementation,

1. Higher PWM frequency lower the boost inductor size. So, control board should have high PWM frequency.
2. For incremental conductance implementation, better to use ADC with higher resolution (favours PV sweep in low Vpv). Atleast with 12 bit ADC (10 bit compromised a lot for low power).
3. Control algorithm implementation and feedback monitoring.

Considering this, I would recommend cRIO for implementing control block functionality.

Power functionality requires custom design or third party boards for Mosfet, inductors and DC Cap.

To my knowledge, a spainsh university used cRIO and typhoon-HIL for designing a grid tied solar inverter.