基于混合储能的光伏发电系统功率波动平抑技术研究

发布时间：2018-10-26 10:26

【摘要】：环境污染问题得到广泛关注,新能源将会逐步取代煤、石油、天然气等传统化石能源。应运而生的分布式发电技术也得到了广泛的应用。其中光伏发电由于其资源广,易获得等优点,得到了快速的发展和广泛的应用。独立运行的光伏发电系统中,外界条件如光照强度、温度的变化会引起光伏发电的输出功率波动,容易导致系统的不稳定,需借助储能系统进行平抑。基于此,本文研究了一种基于混合储能的光伏发电系统,以平抑功率波动,进而提高电能质量。本文首先分析了光伏电池的工作原理,通过仿真实验获得光伏电池的特性曲线。为了实现功率利用的最大化,研究了一种变步长最大功率跟踪方法,相比于传统的最大功率跟踪方法,其跟踪效果更加快速和准确;然后对储能系统进行进一步的研究,将几种储能方式进行比较,研究了基于蓄电池和超级电容的混合储能结构,并利用Simulink中的SimElectronics元件库搭建其仿真模型,相比于SimPowerSystems元件库,其模型更加接近实际,仿真结果更为准确;最后在控制策略方面,研究了一种能够实现能量双向流动的变流器,通过采用PWM对其进行控制,实现对功率波动的平抑,保证输出电压的稳定性和平滑性。基于以上研究,本文搭建了光伏发电系统整体仿真模型,针对光照强度和负载的变化,对系统进行仿真实验,得到其电压波形。通过分析电压谐波含量,验证所提平抑技术的有效性。
[Abstract]:Environmental pollution has been widely concerned, new energy will gradually replace coal, oil, natural gas and other traditional fossil energy. Distributed generation technology has been widely used. Photovoltaic power generation has been rapidly developed and widely used because of its wide resource and easy access. In the independent photovoltaic power generation system, the external conditions such as light intensity and temperature change will cause the output power fluctuation of photovoltaic power generation, which will easily lead to the instability of the system, and need to be stabilized by the energy storage system. Based on this, a hybrid energy storage photovoltaic power generation system is studied in order to stabilize the power fluctuation and improve the power quality. In this paper, the working principle of photovoltaic cell is analyzed, and the characteristic curve of photovoltaic cell is obtained by simulation experiment. In order to maximize the power utilization, a variable step size maximum power tracking method is studied. Compared with the traditional maximum power tracking method, the tracking effect is faster and more accurate. Then the energy storage system is further studied, several energy storage methods are compared, the hybrid energy storage structure based on storage battery and super capacitor is studied, and the simulation model is built by using the SimElectronics component library in Simulink, compared with the SimPowerSystems component library. The model is closer to reality and the simulation results are more accurate. Finally, in the aspect of control strategy, a kind of converter which can realize bidirectional energy flow is studied. By using PWM to control the power fluctuation, the stability and smoothness of output voltage can be guaranteed. Based on the above research, the whole simulation model of photovoltaic power generation system is built, and the voltage waveform of the system is obtained by the simulation experiment aiming at the variation of illumination intensity and load. The effectiveness of the proposed technique is verified by analyzing the voltage harmonic content.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM615

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