基于混合储能的光伏发电并网控制策略研究

发布时间：2018-11-27 15:02

【摘要】：能源危机和环境危机大大促进了风能、太阳能等新能源的发展。而风能和太阳能等新能源系统的输出功率受气候和天气影响波动比较大,在并网时对电能的质量以及电力系统稳定性会有很大影响,所以光伏发电系统需要足够容量的储能设备才能稳定地提供符合质量标准的电能。在传统的分布式发电中,储能单元主要是通过对蓄电池的充放电进行控制来实现能量的存储和调动,在并网时仍会对电网产生较大冲击,导致母线电压的波动,同时对于蓄电池本身的寿命非常不利;因此,本文提出了将混合储能系统应用于光伏发电系统并网中,并通过光伏发电系统和储能系统之间互补的特点进行组合构成一个小型的微电网系统进行研究。首先,对光伏发电系统的基本组成和原理特性展开研究,重点分析和研究光伏发电系统的各种组成,并且对其进行了比较详细的分类,最后给出相应光伏电池的等效模型和光伏发电输出特性;研究了光伏发电系统并网控制中的一些关键性基础技术为本文微电网并网运行研究提供理论技术支撑。其次,提出一种光伏最大功率点跟踪(MPPT)的控制方法并对蓄电池和超级电容储能的原理进行分析,重点对蓄电池和超级电容这两种储能装置分别进行仿真研究,得到它们各自运用于光伏发电系统的特性,同时利用两者可以进行优势互补的特性,将两者结合以后进行混合储能系统建模和仿真分析,并提出可以实现蓄电池-超级电容快速响应的直流母线电压平衡控制策略。同时研究了用于并网研究的光伏逆变器,逆变器采用恒功率控制策略进行控制,并通过建模和仿真验证了控制方法的正确性。最后,在前面研究的基础上使用Matlab/Simulink搭建结合了光伏发电系统以及蓄电池-超级电容储能系统的微电网模型,并且对它并网运行下的特性进行分析,仿真结果表明,基于混合储能的微电网并网控制策略具有一定的优越性和正确性,验证了光伏发电系统中加入混合储能系统后进行并网的可行性,能够降低瞬间能量不平衡对电网的冲击作用,从而为微电网的实际应用发展提供一定的理论参考和技术支持。
[Abstract]:Energy crisis and environmental crisis have greatly promoted the development of new energy, such as wind energy and solar energy. However, the output power of new energy systems, such as wind and solar energy, fluctuates greatly by climate and weather, which will have a great impact on the quality of electric energy and the stability of power systems when connected to the grid. Therefore, photovoltaic power generation systems require sufficient capacity energy storage equipment to provide stable power to meet quality standards. In the traditional distributed generation, the energy storage unit mainly controls the charge and discharge of the battery to realize the storage and transfer of energy, which will still have a great impact on the grid when connected to the grid, resulting in the fluctuation of bus voltage. At the same time, it is very disadvantageous to the life of the battery itself. Therefore, the hybrid energy storage system is applied to the grid-connected photovoltaic power generation system, and a small micro-grid system is constructed by combining the characteristics of the photovoltaic power generation system and the energy storage system. First of all, the basic composition and principle characteristics of photovoltaic power generation system are studied, and the various components of photovoltaic power generation system are analyzed and studied in detail. Finally, the equivalent model of photovoltaic cells and the output characteristics of photovoltaic cells are given. Some key technologies in grid-connected control of photovoltaic power system are studied in this paper, which provide theoretical and technical support for the research of grid-connected operation of micro-grid. Secondly, a control method of photovoltaic maximum power point tracking (MPPT) is proposed and the principle of storage battery and super capacitor energy storage is analyzed. The characteristics of their application in photovoltaic power generation system are obtained. At the same time, the hybrid energy storage system modeling and simulation analysis are carried out after combining the two characteristics, which can complement each other with each other. The DC bus voltage balance control strategy which can realize the fast response of battery-super capacitor is proposed. At the same time, the photovoltaic inverter used in grid-connected research is studied. The inverter is controlled by constant power control strategy, and the correctness of the control method is verified by modeling and simulation. Finally, on the basis of the previous research, Matlab/Simulink is used to build the microgrid model combining photovoltaic system and accumulate-super capacitor energy storage system, and the characteristics of the system are analyzed. The simulation results show that, The grid-connected control strategy of microgrid based on hybrid energy storage has certain advantages and correctness, which verifies the feasibility of grid connection after the hybrid energy storage system is added in photovoltaic power generation system, and can reduce the impact of instantaneous energy imbalance on the grid. Therefore, it provides some theoretical reference and technical support for the practical application and development of microgrid.
【学位授予单位】：东华理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM615

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