模块化多电平电池储能系统优化控制技术研究

发布时间：2019-01-16 08:24

【摘要】：目前,可再生能源越来越多的接入电网系统。但新能源的发电功率会随不同的气象条件变换,具有很强的间歇性和随机波动性。为了向电网稳定地供电,储能系统对于可再生能源的电力入网不可或缺。同时,向电网中整合进储能系统,还进一步帮助电力系统可靠供电以及稳定运行。在各种方式的储能方式中,可充电电池储能发展较早,其以较高的能量密度及能量转化效率在电化学储能中脱颖而出。随着电池制造技术的持续进步,电池自身性能不断提高,包括电池成组后的性能,人们寄望于可充电电池的大规模储能应用进一步发展,配合独立运行的风能或太阳能电站。可以看到,蓄电池储能有着广阔的发展前景。为了降低大型电池储能系统的建设成本,可以选用一些已用过的电池接入储能系统。迄今为止,无论电池管理系统或并网逆变器都未在操作过程中考虑调节电池堆健康状况的问题。而可充电电池的一个关键技术问题是它的充放电控制,因为合理的充放电是安全使用电池及尽可能延长其寿命的关键因素,这多需要采用与之相结合的充放电控制电路。就储能系统与电网接口逆变器的选择来看,有一种电压源型逆变器近些年来成为研究热点,即模块化多电平变换器(Modular Multilevel Converter, MMC),其可以灵活控制的分模块式充放电操作策略特别适合电池储能系统。另外,其冗余的结构可以保证大容量储能,也可以维持相对稳定的运行。本论文基于MMC的电池储能系统提出了一种新的电池充放电控制策略,根据电网的功率要求变换MMC调制策略,区分储能备用的时间尺度,从而最大程度上延长储能系统中蓄电池的使用寿命。第一章简要介绍了本课题的部分研究背景及意义。第二章模块化多电平电池储能系统分析及基本控制策略。介绍了基于MMC的电池储能系统的基本结构,包括变换器的工作原理,主要控制目标等。第三章电池参数确定、电池模型及电池寿命影响因素。涉及电池常见参数及估测,电池电压和内阻、电池荷电状态、电池健康状态,及几种主要的电池模型、电池管理系统,以及电池老化过程的一些问题。第四章多时间尺度的模块化多电平电池储能系统优化控制策略。具体包括电池组健康状态均衡调节及长时间尺度操作原则,电池能量管理及中期时间尺度操作原则,系统的输出波形质量控制与短期(实时)控制策略,最后是仿真及实验结果。第五章总结概述了本文的研究工作,并展望模块化多电平电池储能系统下一步电池组的寿命优化。
[Abstract]:At present, more and more renewable energy is connected to power grid system. However, the generation power of new energy will change with different meteorological conditions, which has strong intermittency and random volatility. In order to supply power to the power grid stably, the energy storage system is indispensable for the power supply of renewable energy. At the same time, the integration of energy storage system into the power grid, but also to help the power system reliable power supply and stable operation. Among all kinds of energy storage methods, rechargeable battery energy storage developed earlier, its high energy density and energy conversion efficiency stand out in electrochemical energy storage. With the continuous progress of the battery manufacturing technology, the performance of the battery itself has been continuously improved, including the performance of the battery after grouping. People hope to further develop the large-scale energy storage application of the rechargeable battery, and cooperate with the independently operated wind or solar power station. As can be seen, battery energy storage has a broad development prospects. In order to reduce the construction cost of large battery energy storage system, some used batteries can be selected for energy storage system. So far, neither the battery management system nor grid-connected inverter has considered regulating the battery stack health during operation. One of the key technical problems of rechargeable battery is its charge and discharge control, because reasonable charge and discharge is the key factor to safely use the battery and prolong its life as far as possible, which requires the combination of charge and discharge control circuit. From the point of view of the choice of inverter interface between energy storage system and power grid, a voltage source inverter has become a research hotspot in recent years, that is, modularized multilevel converter (Modular Multilevel Converter, MMC),). The modular charging and discharging operation strategy, which can be controlled flexibly, is especially suitable for battery energy storage system. In addition, its redundant structure can ensure large capacity energy storage, but also maintain a relatively stable operation. In this paper, a new battery charge and discharge control strategy based on MMC is proposed. According to the power requirement of power network, the MMC modulation strategy is changed to distinguish the time scale of energy storage reserve. Thus, the service life of battery in energy storage system is prolonged to the maximum extent. The first chapter briefly introduces the research background and significance of this topic. Chapter 2: analysis and basic control strategy of modularized multilevel battery energy storage system. This paper introduces the basic structure of battery energy storage system based on MMC, including the working principle of converter, main control target and so on. Chapter 3 determines the battery parameters, the battery model and the influence factors of battery life. The common parameters and estimation of battery, battery voltage and internal resistance, battery charge state, battery health state, several main battery models, battery management system, and some problems in battery aging process are discussed. In chapter 4, the optimal control strategy of modularized multilevel battery energy storage system with multiple time scales is presented. It includes battery health balance adjustment and long time scale operation principle, battery energy management and medium term time scale operation principle, system output waveform quality control and short term (real time) control strategy. Finally, the simulation and experimental results are given. The fifth chapter summarizes the research work in this paper and looks forward to the battery life optimization in the next step of modularized multilevel battery energy storage system.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TM46

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