| The Maximum power point tracking (MPPT)of wind energy and solar energy has become a hot spots of renewable energy research field at domestic and international. The main purpose of MPPT is to improve the power output efficiency of costly wind power and photovoltaic (PV) generating system, while improved the response speed of system. The good control performances for MPPT directly influence the effective utilization of wind energy and solar energy, while which influence the safety operation of wind power and PV generating system. Some MPPT methods have been applied to the actual product, such as perturb and observe (PO) method, incremental conductance (IC) method and intelligent control method. But due to rapid range in solar radiation, leading to rapid changes in solar output, while the tracking speed of the existing PV MPPT method is slow, and anti-jamming characteristic is poor, and the output efficiency is low, so these shortcomings hampered the promotion of PV generating system. While the time varying and nonlinear of the wind speed induces the instability power output of wind power generating system, and the output efficiency is low, and the response speed is slow, and for this a highly efficient MPPT method for PV and wind power generating system are very important. At the same time solar and wind energy has a very good complementary performance, so the hybrid wind-solar system can decreases the effect of weather changing as compare with the stand-alone photovoltaic or wind power system, which has better output characteristic.This paper find suitable MPPT methods for small-scale and large-scale PV generating system by analyzing and simulating the output characteristic of PV under ideal and partial shaded conditions. Furthermore, a small wind power generating system by using synchronous generator is analyzed, and a MPPT control method for small wind power generating system is suggested in this paper. Then the MPPT of hybrid wind-solar system is realized. In order to decrease the output libration of system, the artificial immune theory is used to improve the system response speed and anti-jamming capability in this paper. Also the improved fuzzy MPPT controller for hybrid wind-solar system is designed and the control circuit is verified to track maximum power point, which achieve the MPPT of hybrid system. Furthermore, the optimal configure of hybrid wind-solar generating system is analyzed in the paper.The maximum energy capture control strategy of distributed hybrid wind-solar system is discussed in this paper. The highly efficient MPPT control method for PV and small wind generator is proposed respectively, and the simulation and experiment results show that the suggested methods is very effectively to improve the anti-jamming capability of system and the response speed. The main research content and innovations include:(1) At the ideal case, the solar radiation of small-scale PV generating system is same under ideal weather conditions, and the PV characteristics is analyzed and simulated. Then the straight-line approximation method is improved, and the diode factor and reverse saturation current of PV array is acquired, and the MPPT algorithm is proposed by optimizing the output current. Then the variable voltage MPPT algorithm is proposed, which improve the conventional constant-voltages method by controlling the optimal output voltage. The merits of proposed algorithm include rapid response speed and high efficiency and easy to implement and so on.(2)An accurate modeling of large PV array is described in order to predict the real global peak. Then, a Matlab-based mode suitable for PV array in partial shading is established, which can be used as a tool to study the global peak distribution on PV array having different configurations and sizes.(3) The large-scale PV generating system may be partial shading under actual conditions, and then the fuzzy perturb PWM MPPT control methods are proposed, which improves the conventional fuzzy logic MPPT method. Then the PO perturb PWM is described which improves the conventional PO method. The proposed methods have high output efficiency and easy to implement because of the perturb PWM has not always been called in the tracking process.(4) The combined fuzzy logic and PO MPPT method for small wind power generating system is suggested in this paper. The simulation results shows that which can improve the output efficiency under different wind speed conditions.(5) The artificial immune theory is used to improve the fuzzy controller because of the output libration of the traditional hybrid wind-solar system is big, and the proposed fuzzy-immune MPPT control method has not only improved the output characteristics of the hybrid wind-solar system, and the response speed is rapid, and the anti - interference ability is high.This work was supported by the Key Program of National Natural Science Foundation of China (60934005), Foundation of Shanghai Science and Technology Development (09195802900), Foundation of Shanghai Education Development (No. 09LM37 and NO. 10LM26), Postdoctoral Foundation of China (No. 20080440088), the Postdoctoral Foundation of Shanghai (No. 08R214134), Technical standard expert item of Shanghai science and technology council (NO. 10dz0502200), the Baiyulan Found for Science & Technology Talents (No. 2007B073 and 2009B075). |
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