含储能装置的独立光伏发电系统研究

发布时间：2018-10-05 15:25

【摘要】：随着人类社会的快速发展,只依靠化石能源已经不能满足日益增长的能源需求,目前全世界都在寻找其替代品。一些清洁、高效、廉价的可再生的能源应该得到很好的开发,如太阳能、风能、地热能等。使用可再生能源还可以控制因过量使用化石能源所带来的大气污染问题,因此许多国家正在鼓励和支持这方面的新研究。在所有的能源中,太阳能是全球范围内最丰富的。只有30%的太阳光被反射回太空,剩下的70%的太阳光被地表吸收。近年来,随着制造光伏电池的材料技术不断进步,光伏电池的效率也在不断地提高,通过对光伏电池进行串并联组合形成光伏阵列,可以满足大功率或是小功率等多种不同应用场合的需求。本文以户用独立光伏发电系统为目标,对系统的结构以及各部分的控制进行了研究。系统包含光伏阵列、Boost升压整流器、单相光伏逆变器、蓄电池、双向DC/DC变换器以及交直流负载。为了保证光伏阵列输出功率最大化,采用了最大功率点跟踪控制(MPPT)实时跟踪其最大功率点;在户用系统中通常采用单相光伏逆变器为交流负载供电,本文在研究了其结构、调制方法和控制策略的基础上,针对传统的PI控制不能对正弦量进行无静差跟踪,设计了一种基于电压有效值闭环控制的单相逆变器控制算法,可以实现对正弦信号的无静差跟踪,具有良好的动静态特性,且原理简单、容易实现;储能装置是户用系统中必不可少的,本文采用铅酸蓄电池作为储能装置,对其结构、原理以及模型进行了研究。双向DC/DC变换器在本系统中起到控制蓄电池充放电、控制直流母线电压等重要作用,本文重点对其进行了研究。在分析了变换器拓扑结构的基础上,分别对其两种工作模式Buck模式和Boost模式进行了建模,并采用了一步模型预测控制以及满意优化控制对变换器进行了控制,仿真结果验证了控制算法的有效性。本文根据户用系统中光伏阵列输出功率与负载功率的实时关系,并结合蓄电池的荷电状态,设计了系统的能量管理策略。策略将负载按重要程度进行分级控制,并建立了五种工作模式,大大提高了系统的可靠性。最后本文在MATLAB/SIMULINK中搭建了整个系统的仿真,验证了各部分控制算法的有效性并观测了系统在不同工作模式下的运行效果。
[Abstract]:With the rapid development of human society, fossil energy alone can not meet the increasing demand for energy. At present, the world is looking for its replacement. Some clean, efficient and cheap renewable energy sources, such as solar, wind, geothermal and so on, should be well developed. The use of renewable energy can also control atmospheric pollution caused by excessive use of fossil energy, so many countries are encouraging and supporting new research in this area. Of all the energy sources, solar energy is the richest in the world. Only 30 percent of the sun's light is reflected back into space, and the remaining 70 percent is absorbed by the earth's surface. In recent years, with the development of the material technology of photovoltaic cells, the efficiency of photovoltaic cells has been improved, and photovoltaic arrays are formed by series-parallel combination of photovoltaic cells. It can meet the needs of many different applications such as high power or low power. In this paper, the structure of the system and the control of each part are studied, aiming at the household independent photovoltaic power generation system. The system includes PV array boost rectifier, single phase photovoltaic inverter, battery, bidirectional DC/DC converter and AC / DC load. In order to maximize the output power of photovoltaic array, the maximum power point tracking control (MPPT) is used to track the maximum power point in real time. In the household system, the single-phase photovoltaic inverter is usually used to supply AC load. On the basis of modulation method and control strategy, a single-phase inverter control algorithm based on voltage RMS closed-loop control is designed, aiming at the traditional PI control can not track sinusoids without static error. It can be used to track sinusoidal signal without static error, has good dynamic and static characteristics, and is simple in principle and easy to realize. The energy storage device is indispensable in household system. In this paper, lead-acid battery is used as energy storage device, and its structure is analyzed. The principle and model are studied. The bidirectional DC/DC converter plays an important role in the control of battery charge and discharge and DC bus voltage. On the basis of analyzing the topology of the converter, the Buck mode and the Boost mode of the converter are modeled, and the one-step model predictive control and the satisfactory optimization control are used to control the converter. Simulation results verify the effectiveness of the control algorithm. According to the real time relationship between the output power and the load power of the photovoltaic array in the household system and combined with the charging state of the battery, the energy management strategy of the system is designed in this paper. The strategy classifies the load according to the degree of importance, and establishes five working modes, which greatly improve the reliability of the system. Finally, the simulation of the whole system is built in MATLAB/SIMULINK, which verifies the effectiveness of each part of the control algorithm and observes the operation effect of the system in different working modes.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM615

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