MPPT Controllers

Comparative Benchmarking of Perturb-and-Observe and Incremental Conductance MPPT Algorithms

This work aims to implement in Matlab and Simulink the perturb-and-observe (P&O) and incremental conductance algorithms that are published in the literature. The main objective is to determine which of these two methods are the most suitable for Maximum Power Point Tracking (MPPT) in order to establish an optimal algorithm if is desired undertake analysis of power depending on solar radiation respectively function of temperature taking into account the modification of change of duty cycle parameter that enter in the MPPT control algorithms of the considered model of photovoltaic (PV) system.

The PV system model used for simulation consists of the PV panel, the variant subsystem of irradiance, the buck converter and the variant subsystem of MPPT controller. Considering the optimal rapport between time of simulation, step change response of buck converter and the maximum power obtained, the best result for P&O and incremental conductance MPPT methods are obtained at the step change of duty cycle deltad=8 ms of MPPT controller.

The incremental conductance algorithm is superior compared with P&O both at power obtained as well as at step recovery of power and variation of temperature.

First are simulated the P&O and incremental conductance algorithms using a step variation of irradiance at ambient temperature and different values of the step change of duty cycle of implemented MPPT algorithms.

Afterwards are given the simulation result for two different irradiance and temperature levels at the optimum step change of duty cycle previously established.

The simulation results are presented in parallel for both MPPT methods at the same step change of duty cycle.

Evaluation of Incremental Conductance MPPT Method for PV Systems

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

The simulation model, implemented 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 implemented 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 of 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.

CLICK HERE TO DOWNLOAD THE PV AND MPPT MODEL PACK (2.63 MB -- Simulink)

Please cite my papers in your work:

I. V. Banu, R. Beniugă and M. Istrate, "Comparative analysis of the perturb-and-observe and incremental conductance MPPT methods," 2013 8TH INTERNATIONAL SYMPOSIUM ON ADVANCED TOPICS IN ELECTRICAL ENGINEERING (ATEE), Bucharest, 2013, pp. 1-4. doi: 10.1109/ATEE.2013.6563483

URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=6563483&isnumber=6563346

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