Study Of MPPT Control Method Based On Fuzzy Logic Control In PV System

Energy shortage and environment pollution accompanied by economic development has attracted public attention. Green and renewable energy has become the key to alleviate the contradiction between economic development and deterioration of ecological environment. Therefore, photovoltaic industry is developing in a rapid pace in recent years. At the same time there are all sorts of technical problems to be solved and perfected.Photovoltaic cell has a series of problems such as low conversion efficiency and its character was affected by external factors easily. Photovoltaic cell should be adjusted to make it always work near the maximum power point. This is the principle of the maximum power point tracking (MPPT) of photovoltaic power generation systems.First, photovoltaic power system is modeled by two parts; One part is the model of photovoltaic cells to study the characteristic curve. Then a model based on state space of the energy management is put forward to simulate the entire photovoltaic power states, through the model the battery condition and the energy transfer process of the whole power system can be mastered. Finally, the simulation results in Matlab verify the reliability and the accuracy of the model.Second, usual MPPT methods are analyzed including perturbation and observation (P&O) and IncCond. Both of the methods have some drawbacks. Therefore, one of the intelligent control methods-fuzzy controls is allowed to access in MPPT in this paper. Fuzzy control has strong robustness, fast response speed, and numerous other advantages, but the steady state residual is relatively large. Therefore, combining the advantages of P&O and fuzzy control, fuzzy disturbance two-ring control MPPT algorithm is proposed in the paper.Finally, P&O, fuzzy control and two-ring control are modeled in the MATLAB, and the MPPT of PV work condition is simulated with change of temperature and light intensity. Moreover, the simulation results show that two-ring control MPPT algorithm has certain advantages on the dynamic performance and static performance compared to the P&O method and the fuzzy control method.The results demonstrate the effectiveness of the algorithm.