ABSTRACT:
In
this paper a novel maximum power point tracking (MPPT) algorithm based on
introducing a complex function for photovoltaic systems is proposed. This
function is used for determination of the duty cycle of the DC-DC converter in
PV systems to track the maximum power point (MPP) in any environment and load
condition. It has been suggested based on analyzing the expected behavior of
converter controller. The function is formed by a two-dimensional Gaussian
function and an Arctangent function. It has been shown that contrary to many
algorithms which produce wrong duty-cycles in abrupt irradiance changes, the
proposed algorithm is able to behave correctly in these situations. In order to
evaluate the performance of method, various simulations and experimental tests
have been carried out. The method has been compared with some major MPPT
techniques with regard to start-up, steady state and dynamic performance. The
results reveal that the proposed method can effectively improve the dynamic
performance and steady state performance simultaneously.
KEYWORDS:
1.
Gaussian-Arctangent Function Based MPPT
2.
Maximum Power
Point Tracking
3.
Photovoltaic
Systems
4.
Variable
Perturbation Frequency
SOFTWARE: MATLAB/SIMULINK
BLOCK DIAGRAM:
Fig.
1. Electrical scheme of the system under test.
EXPECTED SIMULATION RESULTS:
Fig.
2. Output power of PV for battery load in startup test.
(a)
(b)
(c)
(d)
Fig.
3. The output power and duty cycle in step irradiance change for: (a) VSSINC,
(b) LCASF method (c) Fuzzy method and (d) Proposed method.
Fig.
4. Response of algorithms to load change.
(a)
(b)
(c)
(d)
Fig.
5. Response of GAF-VPF algorithm to changes in (a) , (b) , (c) and (d) k.
CONCLUSION:
In this paper a new MPPT algorithm named
Gaussian-Arctangent Function-Based (GAF) method was proposed. The method is
based on introducing a complex function formed by multiplying a two-dimensional
Gaussian function with an Arctangent function. This function is used for
generating an adaptive perturbation size. In addition, variable perturbation
frequency has been utilized for computing the time of applying the next duty
cycle. Simulation results and experimental measurements confirm the
attractiveness and superiority of the proposed method with respect to some
well-known MPPT methods such as variable step-size Incremental Conductance,
load-current adaptive step-size and perturbation frequency (LCASF) and Fuzzy
method. The algorithm behaves robustly in case of load variation and
measurement noise. The other advantage of proposed method is its simplicity of
design. It does not require exact tuning of so many parameters. The only
system-dependent constants required for controller setup are open-circuit
voltage and short-circuit current and standard condition. Although, the
computational cost of proposed method is higher than methods like P&O and
Incremental Conductance, it can be easily implemented in low cost
micro-controllers. All in all, these features make it well-suited for tracking
uncommonly fast irradiance variations like mobile solar applications.
REFERENCES:
[1] Moacyr Aureliano Gomes de Brito, Luigi Galotto, Jr., Leonardo
Poltronieri Sampaio, Guilherme de Azevedo e Melo, and Carlos Alberto Canesin,
„Evaluation of the Main MPPT Techniques for Photovoltaic Applications”, IEEE
Trans. Ind. Electron., vol. 60, no. 3, pp. 1156-1167, March 2013.
[2] C. Hua, J. Lin, and C. Shen, “Implementation of a
DSP-controlled photovoltaic system with peak power tracking,” IEEE Trans. Ind.
Electron., vol. 45, no. 1, pp. 99–107, Feb. 1998.
[3] A.R Reisi, M.H.Moradi, S.Jamasb, “Classification and
comparison of maximum power point tracking techniques for photovoltaic system:
A review”, Renewable & Sustainable Energy Reviews, vol. 19, pp. 433-443,
March 2013.
[4] Qiang Mei, Mingwei Shan, Liying Liu, and Josep M. Guerrero, “A
Novel Improved Variable Step Size Incremental-Resistance MPPT Method for PV
Systems”, IEEE Trans. Ind. Electron., vol. 58, no. 6, pp. 2427-2434, June 2011.
[5] N. Femia, G. Petrone, G.
Spagnuolo, and M. Vitelli, “Optimization of perturb and observe maximum power
point tracking method,” IEEE Trans. Power Electron., vol. 20, no. 4, pp.
963–973, July 2005.
