基于超级电容器—蓄电池储能的光伏系统控制策略与仿真研究

发布时间：2018-06-17 01:07

本文选题：独立光伏系统 + 蓄电池　；参考：《山东大学》2017年硕士论文

【摘要】：随着世界人口压力的上升,环境污染的日趋严重以及能源危机的加深,寻求新型的可替代能源逐渐成为了人类社会能否可持续健康发展下去的瓶颈问题。太阳能发电由于其零二氧化碳、零粉尘、环境友好、成本较低等特点,备受家庭独立分布式发电的青睐。但在多云的天气,有云快速经过的时候,独立光伏系统的输出功率可能会经历一个较大的波动,这时系统的储能元件必须为系统负载提供冲击功率。但传统的蓄电池等对充放电电流有着严格要求,长此以往必将损害蓄电池极板等内部元件,缩短其使用寿命,变相地增加了系统的使用成本。并且,传统光伏系统的MPPT(Maximum Power Point Tracking,MPPT)方法通常采用定步长方法。这种定步长方式虽然有实现简单,成本较低的特点,但会导致系统输出功率有较大的波动,对储能元件造成损害。为解决以上问题,本文针对传统的光伏系统在两个方面进行了改进:一是设计了一种新型的混合储能系统,在这种系统中,超级电容器和蓄电池根据能量水平的不同配合工作,与此同时,为保证储能元件不出现过充或过放,本文也设计了系统的控制规则;二是用对传统的定步长MPPT方法进行了改进,提出了变步长MPPT方案来取代传统的定步长算法;三是基于Simulink平台对系统模型进行了仿真验证。结果显示,系统不仅能够很好地消除输出功率纹波,还能够在输出功率波动时保持蓄电池充电功率和负载功率稳定,从而验证了设计的合理性。
[Abstract]:With the increasing pressure of the world population, environmental pollution and the deepening of the energy crisis, the search for new alternative energy has gradually become the bottleneck of the sustainable and healthy development of human society. Solar power generation is favored by family independent distributed generation because of its characteristics of zero carbon dioxide, zero dust, friendly environment, low cost and so on. However, in cloudy weather, the output power of the independent photovoltaic system may undergo a large fluctuation when the cloud passes quickly, and the energy storage element of the system must provide the impact power for the system load. However, the traditional battery has strict requirements for charging and discharging current. In the long run, it will damage the internal components such as the battery electrode, shorten its service life, and increase the cost of the system in a disguised way. In addition, MPPTT Maximum Power Point tracking (MPPTT) method is usually used in traditional photovoltaic systems. Although this fixed step method has the characteristics of simple realization and low cost, it will lead to great fluctuation of the output power of the system and damage to the energy storage elements. In order to solve the above problems, this paper improves the traditional photovoltaic system in two aspects: first, a new hybrid energy storage system is designed, in which supercapacitors and batteries work in accordance with different energy levels. At the same time, in order to ensure that the energy storage elements do not overcharge or overplay, this paper also designs the control rules of the system. Second, the traditional fixed step size MPPT method is improved, and the variable step size MPPT scheme is proposed to replace the traditional fixed step size algorithm. Thirdly, the system model is simulated and verified based on Simulink platform. The results show that the system can not only eliminate the ripple of output power, but also keep the battery charge power and load power stable when the output power fluctuates, thus validating the rationality of the design.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM615

【相似文献】