储能系统对交流微电网稳定性的作用研究

发布时间：2018-07-24 10:02

【摘要】：随着新能源发电和微电网技术的发展,以及构建环境友好型和谐社会的迫切需求,越来越多的新能源发电接入到微电网当中。而新能源发电对微电网稳定性带来的不利影响需要我们加以重视和解决。储能系统可以为微电网提供快速的能量缓冲,从而使微电网的电压和频率保持稳定,所以储能技术在微电网中发挥的作用也日益凸显。微电网中的储能装置形式多样,安装位置灵活,在合理的控制下可以对微电网的稳定运行提供一定的支撑。本文以孤岛运行的交流微电网为例,研究了储能系统对微电网的频率稳定性改善作用。首先,储能功率控制器在使用锁相环技术采样所需相角值并对有功／无功功率进行解耦时,存在相角值不够精确和功率计算比较复杂的问题。本文采用了无锁相环技术来解决这些问题。在此基础上,建立了一种基于频率跟踪的单一储能功率控制策略。通过仿真结果表明,本文所采用的单一储能控制策略有效地抑制了系统的频率波动,相比于传统单一储能功率控制策略更加明显地改善了系统的频率稳定性。然后,随着越来越多的新能源发电并入微电网当中,有时采用单一储能技术已经不能满足微电网对供电质量和稳定性的要求。这时我们需要使用混合储能技术来解决上述问题。本文使用了由超级电容器和蓄电池组成的混合储能系统。并且采用了模糊控制来协调控制超级电容器和蓄电池之间的运行。仿真结果表明了本文所采用的混合储能控制方案使系统的频率稳定性得到了很好的改善,并且改善效果比使用单一储能控制方案时更加明显。最后,文中给出了本文所用的孤岛运行微电网的MATLAB/simulink仿真模型的搭建步骤和关键模块的设计。同时文中也对实验室可行的微电网实验硬件平台进行了设计。
[Abstract]:With the development of new energy generation and microgrid technology, and the urgent need to build an environmentally friendly and harmonious society, more and more new energy generation is connected to microgrid. However, the adverse effects of new energy generation on the stability of microgrid need to be paid attention to and solved. Energy storage system can provide fast energy buffering for microgrid, so that the voltage and frequency of microgrid can be kept stable, so energy storage technology plays an increasingly important role in microgrid. The energy storage devices in the microgrid have various forms and flexible installation positions, which can provide some support for the stable operation of the microgrid under reasonable control. In this paper, the effect of the energy storage system on the frequency stability of the microgrid is studied by taking the isolated AC microgrid as an example. Firstly, when the phase-locked loop technique is used to sample the required phase angle and decouple the active / reactive power, the phase angle is not accurate enough and the power calculation is complicated. In this paper, phase-free loop (PLL) technique is used to solve these problems. On this basis, a single energy storage power control strategy based on frequency tracking is proposed. The simulation results show that the single energy storage control strategy proposed in this paper can effectively suppress the frequency fluctuation of the system, and improve the frequency stability of the system more obviously than the traditional single energy storage power control strategy. Then, with more and more new energy generation integrated into microgrid, sometimes the single energy storage technology can not meet the demand of power supply quality and stability in microgrid. At this point, we need to use hybrid energy storage technology to solve the above problem. A hybrid energy storage system consisting of supercapacitors and batteries is used in this paper. Fuzzy control is used to coordinate the operation between supercapacitor and battery. The simulation results show that the hybrid energy storage control scheme proposed in this paper can improve the frequency stability of the system, and the improvement effect is more obvious than that of the single energy storage control scheme. Finally, the steps of MATLAB/simulink simulation model and the design of key modules are given. At the same time, the hardware platform of microgrid experiment is designed.
【学位授予单位】：兰州理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM712

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