【作者】 刘立群；

【导师】 王志新；

【作者基本信息】 上海交通大学 ， 电机与电器， 2011， 博士

【摘要】 风能、太阳能的最大能量捕获已经成为国内外新能源领域的研究热点,采用最大功率跟踪(MPPT)方法旨在最大限度地提高风电机组和光伏发电系统的电能输出效率和系统的响应速度。MPPT控制方法的优劣直接关系着风能和太阳能的有效利用效率和系统的安全运行性能。目前,扰动观察法、增量电导法和智能控制法等MPPT方法已经被应用到实际产品中。但是由于太阳辐射变化迅速,导致光伏输出变化迅速,而现有的光伏MPPT方法跟踪速度慢、抗干扰能力差和输出效率低等缺点阻碍了光伏发电的进一步推广。而时变非线性的风速导致风电机组的输出不稳定,输出效率低和响应速度慢,因此一种高效的MPPT方法对于风电机组和光伏发电系统而言都是非常重要的。同时太阳能和风能具有很好的互补性,风光互补系统与独立式光伏或风电机组相比可以有效降低天气变化对系统的影响,使系统具有更好的输出特性。本文通过对理想状况和部分遮蔽情况下光伏的不同输出特性的分析与仿真,分别找到了适于小型和大型光伏发电系统的MPPT控制方法;通过对选用同步发电机的小型风电机组的分析,找到了适于小型风电机组的MPPT控制方法,并实现了风光互补系统的MPPT;为了减小系统的输出振动,文中将人工免疫理论应用到风光互补系统中,增强了系统的响应速度和抗干扰能力。同时设计了改进模糊的风光互补系统MPPT控制器,并对控制电路进行了实验验证,实现了风光互补系统的互补和最大功率跟踪。此外对风光互补系统的优化匹配进行了分析。本文对分布式风光互补系统的最大能量捕获控制策略进行了探讨。针对小型风电机组和光伏发电系统分别实现了高效的最大功率跟踪控制方法,仿真和实验结果表明所采用的方法是有效的,提高了系统的抗干扰能力并增加了响应的速度。主要的研究内容和创新成果包括:(1)在理想情况下,针对小型光伏发电系统的太阳照射强度相同的特点,对光伏输出特性进行了分析和仿真,通过对直线近似法的改进,得到了求取二极管品质因子和反向饱和电流的新方法,实现了控制优化输出电流的最大功率跟踪算法;通过对传统恒定电压法的改进,实现了控制优化电压的变电压最大功率跟踪算法;所实现的算法具有响应速度快、效率高、易于实现等特点。(2)为了预测光伏阵列的实际峰值点,精确建模了有部分遮蔽的大型光伏阵列的输出特性,并通过Matlab软件构建了大型光伏阵列输出特性分析模型,它可以作为预测不同结构和尺寸的光伏阵列全局峰值分布的工具。(3)在实际情况下,针对大型光伏发电系统有可能被部分遮蔽的情况,实现了基于模糊逻辑的模糊扰动和基于扰动观察法的扰动PWM控制方法,由于扰动PWM在跟踪过程中并不是一直被调用,所实现的方法具有较高的输出效率,且易于实现。(4)针对小型风电机组实现了将模糊逻辑和扰动观察相结合的MPPT控制方法,仿真结果表明该MPPT控制方法在各种风速情况下都具有较高的输出效率。(5)针对传统风光互补系统输出振动较大的情况,利用人工免疫理论改进了模糊控制器,所采用的模糊免疫MPPT控制方法,不但改善了风光互补系统的输出特性,而且响应速度快、抗干扰能力强。本文得到国家自然科学基金重点项目(60934005);上海市科技发展基金(09195802900);上海市教育发展基金(09LM37,10LM26);中国博士后基金(20080440088) ;上海市博士后基金(08R214134) ;上海市科委技术标准专项(10dz0502200);上海市白玉兰科技人才基金(2007B073,2009B075)的资助。更多还原

【Abstract】 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).更多还原