Adaptive perturb and observe algorithm for photovoltaic maximum power point tracking

Abstract

The optimisation of energy generation in a photovoltaic (PV) system is necessary to let the PV cells operate at the maximum power point (MPP) corresponding to the maximum efficiency. Since the MPP varies, based on the irradiation and cell temperature, appropriate algorithms must be utilised to track the MPP. This is known as maximum power point tracking (MPPT). Different MPPT algorithms, each with its own specific performance, have been proposed in the literature. A so-called perturb and observe (P&O) method is considered here. This method is widely diffused because of its low-cost and ease of implementation. When atmospheric conditions are constant or change slowly, the P&O method oscillates close to MPP. However, when these change rapidly, this method fails to track MPP and gives rise to a waste of part of the available energy. An adaptive P&O method is proposed in this study that has faster dynamics and improved stability compared to the traditional P&O. The MPPT algorithm was set up and validated by means of numerical simulations and experimental tests, confirming the effectiveness of the method

Sistema Fotovoltaico com Condicionamento Ativo de Energia Usando Mppt Baseado em Pso e Malha Feed-forward de Controle de Tensão do Barramento Cc

“…Além disso, o algoritmo MPPT-P&O é executado em um tempo de amostragem constante ( ) tal que pequenos valores de implicam em transientes rápidos quando ocorrem mudanças na radiação solar. Por outro lado, grandes valores de tornam o sistema mais lento, causando perdas na potência extraída do arranjo fotovoltaico [11], [12].…”

“…Normalmente, técnicas de MPPT tradicionais, as quais são baseadas em estratégias perturbativas, tais como condutância incremental (IC -Incremental Conductance) [8], [9] ou perturba e observa (P&O -Perturb & Observe) [8]- [12], têm sido usadas para realizar o rastreamento do ponto de máxima potência (MPP) do arranjo fotovoltaico. Embora os algoritmos de MPPT baseados nos métodos IC e P&O terem um bom desempenho considerando o arranjo fotovoltaico irradiado uniformemente, seu desempenho pode ser fortemente afetado quando estes estão operando sob condições de sombreamento parcial.…”

Auto-tuning of PV controllers to improve the speed response and stability of the P&O algorithm

“…Different approaches to optimize the P&O algorithm have been published; for instance, the work in (Femia, Granozio, Petrone, Spagnuolo, & Vitelli, 2007) presents an optimizing of the P&O algorithm using a predictive-adaptive control, where the magnitude of the duty cycle perturbation changes to speed up the tracking the MPP. Similarly, in (Kumar, Student, Kumar, & Senior, 2013), (Piegari & Rizzo, 2010), and (Wang, Wang, & Meng, 2012), adaptive techniques are used to optimize the P&O algorithm with two main objectives: to ensure stability at both transients and steady state, and to improve the tracking speed when the MPP changes due to climatic perturbations. However, the works reported in (Femia et al, 2007), (Kumar et al, 2013), (Piegari & Rizzo, 2010) and (Wang et al, 2012) do not take into account the C b voltage oscillations generated by the inverter; hence, such techniques do not ensure a stable operation of a grid-connected PV system.…”

“…Similarly, in (Kumar, Student, Kumar, & Senior, 2013), (Piegari & Rizzo, 2010), and (Wang, Wang, & Meng, 2012), adaptive techniques are used to optimize the P&O algorithm with two main objectives: to ensure stability at both transients and steady state, and to improve the tracking speed when the MPP changes due to climatic perturbations. However, the works reported in (Femia et al, 2007), (Kumar et al, 2013), (Piegari & Rizzo, 2010) and (Wang et al, 2012) do not take into account the C b voltage oscillations generated by the inverter; hence, such techniques do not ensure a stable operation of a grid-connected PV system. This paper is focused on the improvement of the tracking speed of the P&O algorithm, whose operation is defined by two parameters: the disturbance period T a and the disturbance magnitude ΔV.…”

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“…Validity of the photovoltaic module with P & O method allowed better performance of MPPT due to variation of both power and voltage. Using perturbation parameter 0.1 V for proposed method in the MPPT, solar panel was able to optimize power output up to 24.49 W using load 5 Ω in 523 W/m 2 irradiance level compared with conventional method using identical load and irradiance level 527 W/m2 providing power output 15.37 W. [3].…”