基于电池储能的组合级联式功率转换系统研究

发布时间：2018-05-03 17:46

本文选题：功率转换系统 + 组合级联式　；参考：《北京交通大学》2014年硕士论文

【摘要】：近年来,全球电力需求不断增长,传统石化资源日渐匮乏,新能源技术得到了快速发展和应用。然而,分布式电源并网给电力系统的稳定性和可控性带来了极大的挑战。电池储能系统为解决这一问题提供了新的技术和手段。作为电池储能系统的重要组成部分,功率转换系统将成为研究的重点。本文依托北京市科技计划项目“光伏并网用统一功率控制装备及直流微网技术研究与示范应用(D131104002013003)”,对基于电池储能的组合级联式功率转换系统进行了理论和仿真研究,主要内容如下：首先,提出了一种组合级联式功率转换系统的拓扑结构,该系统主要由储能电池组、隔离型半桥DC/DC变换器和链式DC/AC变换器组合而成。分析了这两类变换器的基本工作原理、控制方式和功率传输特性。结合实验室低压物理模型的开发,选取了功率转换系统主电路的拓扑结构及主要参数。其次,设计了功率转换系统的协调控制策略：为确保功率的动态平衡,实现直流侧电容电压的恒定,DC/DC侧采用移相控制和占空比控制；为了满足系统功率传递的目标,DC/AC侧采用直接电流解耦控制；为提高装置的响应速度和改善直流侧电容电压的品质,提出了DC/DC和DC/AC的协调控制策略,将电网侧的实时功率指令前馈给DC/DC侧。在PSCAD/EMTDC环境下建立了基于锂电池储能的组合级联式功率转换系统模型,应用所提出的一整套协调控制策略,对装置的正常调节工况、电池组额定参数和荷电状态不同等工况进行了仿真,验证了控制策略的有效性。结果表明：该装置在所提出的协调控制策略下具有较宽的电压匹配能力,电池状态适应能力强,且控制的响应速度较快,能实现大容量储能和双向功率调节。最后,为了应对链式电池储能系统中的SOC不均衡问题,研究了基于调制波幅值微调的SOC自均衡控制策略,对电池组荷电状态不均衡的情况进行仿真,验证了该控制策略的有效性。此外,分别对载波移相SPWM控制和SOC自均衡控制进行了谐波分析。结果表明：采用基于调制波幅值微调的SOC自均衡控制策略,能够合理分配各电池组承担的功率调节量,使SOC趋于一致,提高了整个功率转换系统的容量和可用率,但是由于改变了调制波幅值,会对输出电压的谐波性能造成一定影响。
[Abstract]:In recent years, the global electricity demand is increasing, the traditional petrochemical resources are increasingly scarce, the new energy technology has been rapidly developed and applied. However, the stability and controllability of the power system are greatly challenged by the interconnection of distributed power sources. Battery energy storage system provides new technology and means to solve this problem. As an important part of battery energy storage system, power conversion system will become the focus of research. In this paper, based on Beijing Science and Technology Project "Research and demonstration application of unified power control equipment and DC microgrid technology for photovoltaic grid-connected system, D131104002013003", the theory and simulation of combined cascade power conversion system based on battery energy storage are studied. The main contents are as follows: Firstly, the topology of a combined cascade power conversion system is proposed. The system consists of a battery pack, an isolated half-bridge DC/DC converter and a chain DC/AC converter. The basic working principle, control mode and power transmission characteristics of the two kinds of converters are analyzed. Combined with the development of laboratory low-voltage physical model, the main circuit topology and main parameters of power conversion system are selected. Secondly, the coordinated control strategy of power conversion system is designed: in order to ensure the dynamic balance of power, the DC / DC side of DC / DC side adopts phase shift control and duty cycle control; In order to satisfy the power transfer target of the system, direct current decoupling control is adopted in DC / AC side, and the coordinated control strategy of DC/DC and DC/AC is proposed to improve the response speed of the device and the quality of the capacitor voltage on the DC side. The real-time power command of the power network side is fed forward to the DC/DC side. The combined cascade power conversion system model based on the energy storage of lithium battery is established in PSCAD/EMTDC environment. A set of coordinated control strategies are proposed to regulate the normal operating conditions of the device. The simulation results show that the control strategy is effective. The results show that the proposed coordinated control strategy has the advantages of wide voltage matching ability, strong adaptability to battery state, and fast response speed, which can realize large capacity energy storage and bidirectional power regulation. Finally, in order to deal with the problem of SOC imbalance in chain battery energy storage system, the self-equalization control strategy of SOC based on modulation amplitude fine-tuning is studied, and the unbalance of charge state of battery pack is simulated. The effectiveness of the control strategy is verified. In addition, the harmonic analysis of carrier phase shifted SPWM control and SOC self-equalization control are carried out respectively. The results show that the SOC self-equalization control strategy based on the modulation amplitude fine-tuning can reasonably distribute the power regulation carried by each battery pack, make the SOC tend to be consistent, and improve the capacity and availability of the whole power conversion system. However, the harmonic performance of the output voltage will be affected by changing the amplitude of the modulation.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM46

【参考文献】