Modeling of Maximum Power Point Tracking Algorithm for Photovoltaic Systems

Modeling of Maximum Power Point Tracking Algorithm for Photovoltaic Systems

This work presents the performance evaluation of incremental conductance maximum power point tracking (MPPT) algorithm for solar photovoltaic (PV) systems under rapidly changing irradiation condition.

The simulation model, carried out in Matlab and Simulink, includes the PV solar panel, the dc/dc buck converter and the MPPT controller. This model provides a good evaluation of performance of MPPT control for PV systems.
The incremental conductance algorithm was tested against fast change of solar radiation (step change in irradiance). The simulation results show that the MPPT controller increase the overall efficiency of the PV system and the incremental conductance method is effective at rapidly changing irradiance level.

The MPPT controller with incremental conductance method is carried out using the Stateflow toolbox from Simulink.
Stateflow is a very powerful tool that graphically allows to do state machines and logical event based controllers and can be created states and transitions. All these transitions are based on decision based on measurement of system. When the program running can be visualized how is making the decision and how the system is moving from one state to another.

The simulation results are presented and analyzed to validate that the proposed simulation model is effective for the MPPT control of PV systems at rapidly changing irradiation condition.
The simulation was first run with the MPPT controller using the incremental conductance algorithm. As the irradiance is changing, the MPPT controller makes the power coming out of the PV array to be kept at maximum.
Then, the simulation was run without the MPPT controller (the PV array was directly connected to the load) under the same irradiance level. Therefore, the output power of PV array is smaller than in previous case.

Finally, the incremental conductance MPPT method was tested under fast changing irradiance level. The step change response of power for the PV array and dc/dc buck converter is analyzed considering two cases of step size of duty cycle of MPPT controller.

Please cite my paper in your work:

I. V. Banu and M. Istrate, "Modeling of maximum power point tracking algorithm for photovoltaic systems," 2012 International Conference and Exposition on Electrical and Power Engineering, Iasi, 2012, pp. 953-957. doi: 10.1109/ICEPE.2012.6463577
URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=6463577&isnumber=6463569