A variable step maximum power point tracking algorithm based on gradient descent method

Solar energy is considered as one of the most effective, less expensive, harmless and less environment pollution effect of renewable energy sources. The problem of using solar power including varying weather condition brings different output power of the photovoltaic (PV) array, which may cause a serious waste of solar power. For solving this problem, a Maximum power point tracking (MPPT) strategy is always required to make PV array keep giving maximum power under different environment condition. In this paper, a variable step MPPT based on gradient descent method is proposed for faster and more precise tracking process. A model based on matlab/simulink was established to analysis the performance of the proposed MPPT strategy. Simulation proves that this MPPT method is practical with a better performance than the traditional strategies.