分布式光伏发电微电网供能系统研究.pdf

山东大学博士学位论文目录摘要.I ABSTRACT.V第1章绪论.11.1 课题背景及意义.11.2 分布式光伏发电微电网供能系统现状.61.2.1 光伏发电现状及前景.61.2.2 电能供应发展历史及直流供电的意义.91.2.3 微电网技术发展现状.141.3 论文的主要工作及创新点.19第2章分布式光伏发电微电网建模及仿真基础.232.1 光伏电池建模及仿真.232.1.1 光伏电池工作原理.23 2.1.2硅光伏电池等效电路和输出特性.252.1.3光伏电池的分类及硅光伏电池在MATLAB下的仿真模型.292.2 光伏发电系统常用DC/DC电路仿真.332.2.1 光伏发电系统常用DC/DC电路分类及应用.33222光伏发电系统常用DC/DC电路仿真.342.3 光伏电源模块控制及仿真.352.3 1光伏电源模块.352.3 2光伏电源常用MPPT方法.362.3 3直流微电网中光伏电源实施MPPT的新方法.37 2.3 4仿真验证.402.4 本章小结.42第3章独立型光伏发电系统统一能量控制策略.433.1 独立型光伏发电系统背景及意义.433.1.1 便携式光伏电源.433.1.2 独立型光伏发电系统及其作用.44山东大学博士学位论文113独立型光伏发电系统应用现状.443.2 典型独立型光伏发电系统及工作原理.453.2.1 光伏水泵.453.2.2 户用光伏发电系统.463.2.3 扬水与照明综合光伏发电系统.473.2.4 含互补电源光伏发电系统.493.3 独立型光伏发电系统统一能量控制策略.503.3.1 独立型光伏发电系统能量流动差异.50332统一能量控制策略.523.4 统一能量控制策略下光伏电源最优工作点追踪.583.5 仿真验证.583.6 小结.60第4章分布式光伏发电直流型微电网及其控制策略.614.1 光伏发电直流微电网背景及意义.614.1.1 直流微电网存在的客观要求.614.1.2 直流微电网应用现状.624.1.3 直流微电网供电特点.644.2 含光伏发电直流型微电网.654.2.1 楼宇光伏发电现状及采用直流供电的节电效果.654.2.2 楼宇直流型微电网.674.3 分布式光伏发电直流型微电网及其控制策略.694.3.1 分布式光伏发电直流型微电网拓扑结构.694.3.2 分布式光伏发电直流型微电网工作原理.704.4 仿真验证.754.5 本章小结.78第5章分布式光伏发电微电网并网逆变器控制策略.815.1 光伏发电并网逆变器的研究现状.815.1.1 光伏发电并网逆变器概况.815.1.2 两级光伏发电并网逆变器传统控制策略.84山东大学博士学位论文5.2 两级光伏发电并网逆变器无直流链电压传感器控制策略.885.2.1 两级单相并网逆变器无直流链电压传感器控制策略.895.2.2 两级三相并网逆变器无直流链电压传感器控制策略.935.3 两级光伏发电并网逆变器直流侧无电压传感器控制策略.9653.1两级单相并网逆变器直流侧无电压传感器控制策略.965.3.2两级三相并网逆变器直流侧无电压传感器控制策略.985.33两级并网逆变器直流侧无电压传感器MPPT改进控制策略995.4 仿真验证.1005.4.1 两级三相并网逆变器无直流链电压传感器控制策略.1005.4.2 两级并网逆变器直流侧无电压传感器及MPPT改进控制策略1025.5 本章小结.103第6章分布式光伏发电交直流型微电网及其控制策略.1056.1 交流微电网逆变器并联常用控制策略.1056.2 分布式交直流型微电网常用拓扑结构.10663分布式交直流型微电网工作原理.1076.4 分布式光伏发电交直流型微电网.1086.4.1 分布式光伏发电交直流型微电网拓扑.1086.4.2 直流微电网工作原理.1086.4.3 并网模式下交流微电网工作原理.1096.4.4 离网模式下交流微电网工作原理.1116.5 仿真验证.1156.6 本章小结.117第7章光伏发电微电网供能系统实验平台.1197.1 光伏发电微电网实验平台的设计.1197.2 光伏发电微电网实验平台的建立.1207.2.1 光伏电池阵列、各种交直流负荷和储能装置的配置.1207.2.2 实验平台各种变换电路及控制器制作.1227.3 实验平台用于无逆流光伏发电直流型微电网研究及可行性验证_1257.3.1 无逆流光伏发电直流型微电网拓扑结构.125m山东大学博士学位论文73.2无 逆流光伏发电直流型微电网控制策略.1277.3.3 无逆流光伏发电直流微电网实验平台验证.1287.4 本章小结.129第8章结论与展望.131参考文献.135致谢.145攻读博士学位期间发表的学术论文.147攻读博士学位期间参加的科研工作.148IV山东大学博士学位论文CONTENTSCHINESE ABSTRACT.IABSTRACT.VChapter 1 Introduction.1LI Background and Significance of The Subject.11.2 The Present Situation of Distributed PV Microgrid.61.2.1 The Present Situation and Prospect ofPV Generation.61.2.2 History of Power Supply and Significance of DC Power Supply.91.2.3 The Development Status of Microgird.141.3 Organization and Innovation Points of the Dissertation.19Chapter 2 Modeling for Distributed PV Microgrid and Its Simulation.232.1 PV Cell and Its Simulation.232.L1 Working Principle of PV Cell.232.1.2 The Equivalent Circuit and Output Characteristics of Silicon PV Cells 252.1.3 Classification ofPV Cells and The Simulation Model of Silicon Photovoltaic Cells Based on MATLAB.292.2 Common DC/DC Simulations ofPV Systems.332.2.1 Classification and Application of DC/DC Circuit in PV Systems.332.2.2 Common DC/DC Simulation ofPV Systems.342.3 Control and Simulation ofPV Generation Modules.352.3 1 PV Generation Module.352.3 2 MPPT Mode ofPV Generation.362.3 3 Novel Methods to Realise MPPT in DC Microgrid.372.3 4 Verification by Simulation.402.4 Summary.42Chapter 3 Unified Energy Control Strategy of Stand-alone PV System.433.1 Background and Significance ofPV System.43v山东大学博士学位论文3.1.1 Portable PV Power.433.1.2 Stand-alone PV System and Its Function.443.1.3 Application of Stand-alone PV System.443.2 Typical Stand-alone PV Systems and Their Principle.453.2.1 PVPump.453.2.2 Household PV System.463.2.3 Pumping and Lighting Integrated PV System.473.2.4 PV System With Complementary Power Source.493.3 Unified Energy Control Strategy of Stand-alone PV System.503.3.1 Energy Flow Diflferences between Stand-alone PV Systems.5033.2 Unified Energy Control Strategy.523.4 Optimal Operating Point Tracking in The Case of Unified Energy Control Strategy.583.5 Verification by Simulation.583.6 Summary.60Chapter 4 DC Micro-grid Based on Distributed PV Generation and Its Control Strategy 614.1 Significance of DC Micro-grid Based on Distributed PV Generation.614.1.1 Requirements of DC Micro-grid.614.1.2 Present Application Situation of DC Micro-grid.:.624.1.3 Power Supply characteristics of DC Micro-grid.644.2 DC Micro-grid Including PV Generation.654.2.1 Present Situation of Building Integrated PV Generation and the Benefit.654.2.2 Building DC Micro-grid.674.3 DC Micro-grid Based on Distributed PV generations and Its Control Strategy 694.3.1 Topology of The DC Micro-grid.69432 Working Principal of The DC Micro-grid.704.4 Verification by Simulation.754.5 Summary.78VI山东大学博士学位论文Chapter 5 The Control Strategy of Grid-Connected PV Inverter.815.1 Research Status of Grid-connected PV Inverter.815.1.1 Overview.815.1.2 Traditional Control Strategy of Two-Stage Grid-connected PV Inverter.845.2 Indirect DC Jink Voltage Control Strategy of Two-stage Grid-connected PVInverter Without DC Jink Voltage Sensor.885.2.1 Control Strategy of Two-stage Single-phase Grid-connected PV Inverter 89522 Control Strategy of Two-stage Three-phase Grid-connected PV Inverter.935.3 Control Strategy of Two-stage Grid-connected Inverter Without Dc-side VoltageSensor.965.3.1 Control Strategy of Two-stage Single-phase Grid-connected Inverter.9653.2 Control Strategy of Two-stage Three-phase Grid-connected Inverter.985.3.3 Improvement of MPPT Scheme in Control Strategy W汕out Dcside Voltage Sensor.995.4 Verification by Simulation.10(T5.4.1 Indirect DC-link Voltage Control Strategy of Two-stage Three-phase Grid-connected PV Inverter.100.5.4.2 Control Strategy W汕out Dc-side Voltage Sensor With Improvement ofMPPT Scheme.1025.5 Summary.103Chapter 6 AC/DC hybrid Micro-gird Based on Distributed PV Generations and Its control strategy.1056.1 Commonly Used AC Micro-grid Control Strategy for Parallel Inverter.1056.2 Commonly Used AC-DC Micro-grid Topology.1066.3 Working Principal of AC-DC Micro-grid Based on Distributed Generation.1076.4 AC-DC Hybrid Micro-grid Based on Distributed PV Generations.1086.4.1 Topology of AC-DC Micro-grid.1086.4.2 Working Principal of DC Micro-grid.1086.4.3 Working Pricipal of AC Micro-grid Under Grid-connected Situation.109VII山东大学博士学位论文6.4.4 Working Pricipal of AC Micro-grid Under island Situation.Ill6.5 Verification by Simulation.1156.6 Summary.117Chapter 7 Experimental Platform of Micro-grid.1197.1 Design of Experimental Platform of Micro-grid.1197.2 Construction of Experimental Platform of Micro-grid.1207.2.1 Configuration of Distributed PV Generations,Energy storage Device.1207.2.2 Manufacture of Converter and Controller.12273 Research and Feasible Verification of Experimental Platform for Non-reflux DCMicrogrid.1257.3.1 Topology of Non-reflux DC Microgrid.1257.3.2 The Control Stratergy.1277.33 Experimental Verification.1287.4 Summary.129Chapter 8 Conclusion and Prospect.131References.135Acknowledgments.145Publications.147Research activities.148VIII山东大学博士学位论文摘要以太阳能、风能等可再生能源为主的新能源大规模应用具有可持续性，逐步 发展成为化石能源的主要替代能源。光伏发电技术是有效利用太阳能的主要方式 之一，具有许多优点而得以广泛应用，出现了众多容量、规模和运行方式各异的 光伏发电系统，按与公共电网的相互关系，分为独立型和并网型两大类。独立型 系统与公共电网没有任何联系，主要安装在无电和公共电网覆盖薄弱地区，用于 满足人们的基本电能需求，可靠性低；并网型光伏发电系统一般安装在城市或农 村村落等容易获得公共电网支撑的地区，克服了光伏电池出力不稳等缺点，提高 了系统供电可靠性。近年来，在环境保护和能源危机频发双重压力下，并网型光 伏发电系统得到较快发展并成为当今光伏发电技术发展的主要方向，其典型应用 之一有在中心城镇实施的光伏屋顶和分布式光伏发电微电网。.分布式发电和微电网技术的提出和应用，适用于太阳能等可再生能源地域分 散的特点，充分利用了分布式可再生能源发电紧靠本地负荷中心和无污染的优 点。光伏发电微电网内多光伏电源之间、光伏电源与储能装置之间的协同供电，克服了光伏电源出力不稳的缺点。光伏电源具有直流电源特性，传统交流供电方式需要并网逆变器连接电源g 电网，效率低，成本高。采用光伏电源直接直流供电模式能提高电能综合利用效 率，降低系统成本；直流微电网可以通过直流变换电路简单高效地接纳分布式光 伏电源，以及高效率地为本地直流负荷提供电能。本文以分布式光伏发电微电网供能系统的高效应用为出发点，结合光伏电 源、储能装置和负荷的供、用电特性，研究了独立型光伏发电系统和分布式光伏 发电并网系统的新型控制策略,分布式光伏发电直流型微电网拓扑结构与控制策 略以及分布式光伏发电交直流型微电网控制策略，基于中心城镇办公楼宇供电特 点，建设了一套分布式光伏发电微电网实验平台，可获得微电网运营时的实际数 据，验证了分布式光伏发电直流微电网简单高效接纳分布式光伏电源，以及为直 流负荷高效率提供电能。论文所做主要工作如下：(1)提出了一种对光伏电源实施最大功率追踪的新方法。在直流微电网中，山东大学博士学位论文光伏直流变换电路输出电压可保持稳定。本文据此提出了一种把直流变换电路占 空比和光伏电池电流一起作为输入变量来实施最大功率追踪的方法。（2）提出独立型光伏发电系统统一能量控制策略。基于能量平衡原理，根 据母线电压变化，实现光伏电池输出、蓄电池充放电和负荷供电的统一控制，实 现了对光伏电源功率的平滑控制，省略了传统控制下的工作模式转换。（3）提出了一种分布式光伏发电直流型微电网拓扑结构及其控制策略。微 电网内光伏电池阵列因地制宜分布式配置；设置电压较低的直流分支母线，既方 便光伏电池阵列高效接入，又方便供电电压等级不高的直流负荷获取电能；设置 高压直流主母线联接各供电单元和储能装置,便于较远距离交换电能时降低电路 损耗。（4）提出了一种可应用于分布式光伏电源和光伏发电微电网并网发电的两 级三相并网逆变器无直流链电压传感器控制策略。该控制策略在不降低逆变器整 体性能的基础上，取消了直流链电压传感器及其相关电路。（5）在上述两级并网逆变器无直流链电压传感器控制策略的基础上，提出 了一种可应用于分布式光伏电源的直流侧无电压传感器的两级并网逆变器控制 策略。该控制策略在上述两级并网逆变器无直流链电压传感器控制策略保持直流 链电压稳定的基础上，进一步取消了分布式光伏电源并网系统直流侧所有电压传 感器及其相关电路。（6）在分布式光伏发电交直流型微电网中，根据交直流型微电网和分布式 光伏电源特点，提出一种交流微电网离网模式下逆变器并联控制策略。（7）设计并开发了一套分布式光伏发电微电网实验平台。在对分布式光伏 发电和微电网仿真研究的基础上，根据办公楼宇供电现状及特点，建立了一套含 光伏电源、储能装置、本地交流和直流负荷的分布式光伏发电微电网实验平台，通过实验获取微电网运行数据,来研究和验证分布式光伏发电系统和微电网控制 策略等。理论分析、仿真及实验数据表明：相对传统光伏发电系统，本文研究的分布 式光伏发电系统能简化硬件配置，提高系统供电可靠性，降低系统建设和维护成 本；提出的分布式光伏发电微电网拓扑结构和控制策略能简单高效接纳光伏电 源，高效率地为本地负荷提供电能，确保系统稳定可靠运行。山东大学博士学位论文关键词：光伏发电；最大功率追踪；分布式；微电网；并网逆变器；实验平台m山东大学博士学位论文IV山东大学博士学位论文ABSTRACTThe application of renewable energy,such as solar energy and wind energy,has emerged and gradually became one of alternatives of fossil fuel.The photovoltaic(PV)technology,one of the most efficient ways of solar energy utilization,is applied broadly in various capacities,scales and operation types.Compared to traditional generation system,the PV generation is costly,instable and needs complex control method.The distributed PV generation systems can be divided into the stand-alone systems and grid-connected systems.Stand-alone systems completely independent from grid and they are mainly configured in the area without grid or weakly covered by grid to meet the electricity demand but fail to guarantee the reliability of the PV system under different loads.On the other hand,the grid-connected systems are constructed in grid covered areas like cities or villages,which overcome their inability to output power continuously and stably,and improve the reliability of the PV systems.Recently under the great pressure of environment and fuel crisis,the grid-connected systems are now developing fast and the typical applications are PV roof or microgrid,which are usually constructed in the city.The proposal and application of distributed generation and microgrids produce an efficient solution to the problem that the solar energy is distributed sparsely,the power sources are close to the loads and they make little pollution.The cooperation among several power sources or between sources and storages has overcome the fluctuation problems of the output power.The PV generation belongs to DC generation,making traditional AC power supply less flexible and effective.DC microgrid helps to work with distributed PV and provides effective electricity to local DC loads.This paper pursues on the high efficient 呼plication of PV system and low building costs and focuses on the topologies and control methods of DC microgrid control strategies of grid-connected PV systems and AC/DC hybrid microgrids.山东大学博士学位论文In the studying process,following main results are obtained:(1)The operation principles and equivalent circuits of PV cells and PV arrays are analyzed.Traditional methods is subjected to interruption of sensors,causing the lost of reliability.And a new MPPT method is proposed:the method takes the combination of the current from the PV array and the duty cycle of the DC-DC converter,rather than the output voltage of the PV array,as the input variables for the MPPT algorithm.This means that the voltage sensor on the output terminal of PV array can be eliminated,avoiding the overuse of sensors in the traditional perturbation and observation method for MPPT.This elimination has improved the reliability of the system,significantly simplifying the configuration and decreasing the construction cost.(2)Topologies and operation principles of stand-alone PV systems are summerized and analyzed.Whats more,a method with a unified power management strategy which concerns the DC-bus voltage variation,PV array output,charge and discharge of the battery and power supplied for the loads,is proposed.The method is a unified control method,which avoids the work mode switch,and consequently the PV source power can be controlled smoothly.In addition,within the unified power management strategy,the working point optimization method fbr the DC converter on the PV cell side is proposed.(3)The paper proposes the topology and control method of a microgrid which can be applied in the DC-load dominated business buildings.In this system,the PV array can be constructed flexibly.A low voltage DC-bus is applied for PV array to plug-in and supplying digital equipments with low DC voltage and a high voltage DC-bus is employed to integrate separate units and batteries with the benefits of reducing circuit losses.The microgrid controls the DC-bus voltage to balance the power in the whole system and guarantees the stability of the system.(4)A control strategy of Two-stage three-phase grid-connected inverters without dc-link voltage sensor is proposed,which can be used in distributed PV system,or grid-connected PV generation in microgrid.Under the premise that overall performance is kept,this strategy eliminates the dc-link voltage sensor and its relevantVI山东大学博士学位论文一circuit.(5)Based on the strategy of Twostage three-phase grid-connected inverters without dc-link voltage sensor stated above and incorporating with perturbation and observation MPPT method,a two-stage grid-connected inverters control strategy without de side voltage sensors is proposed,which can be used in distributed PV generation system.(6)In the distributed PV generation AC/DC hybrid microgrid topology constructed with single DC microgrid and AC microgrid,an oflf-grid paralleled AC inverter control strategy is proposed based on the characteristics of AC/DC microgrid,the instability of distributed PV generation and its PU curve.(7)After the research of distributed PV generation system and PV generation DC microgrid and in order to dig into the rules of microgrid in electric generation in the future and obtain actual operation data of microgrid,an experimental platform of PV generation microgrid is constructed.Analysis and simulations and experiments show the methods proposed in the paper make improvements include simplifications of the system and the increase of reliability.In addition,the characteristics of urban power supply and electricity consumption are analyzed,based on which a PV generation microgrid used under specific condition and its control method are proposed.At last,the paper introduces the microgrid experimental platform.Keywords:PV Generation;MPPT;Distributed;Microgrid;Grid-Connected Inverter;Experimental PlatformVII山东大学博士学位论文第1章绪论1.1 课题背景及意义化石能源的大规模利用是从英国工业革命后人类进入机器时代开始,人们使 用蒸汽机和内燃机把化石能源含有的化学能转化为便于使用的机械能。电能的发 现和使用，使得人们可以寻求一种集中把化石能源转化为电能，然后便捷、可靠 地提供给用户，满足人们各种能源需求的供给方式，并发展产生了早期电力系统。电力系统的发展和人们生活质量的提高相辅相成，两者在最近几十年均跃升到一 个较高水平。如今电力系统已经形成一个超大规模，发、输、配、供电网络层次 分明的互联网络，人们在生产、生活的各个方面，已经离不开电能的使用。人们 生活质量提高的同时促进了人均以及总体能源消耗水平的急剧上升，由此利用化 石能源带来的环境问题逐渐显现并日益突出。随着人们对能源需求的加速发展，传统化石能源供应接近极限，时常造成交通运输、电力工业所需能源的供应短缺,引起包含能源在内的各种商品的价格上涨甚至供应中断，产生波及人们生产、生 活各方面的能源危机|臼。自20世纪七十年代以来，波及全球的能源危机已出现过多次，并且出现的 频率越来越快以及产生的影响越来越大。随着现代科学技术的发展，以及能源危 机频发和环境保护压力的增大，造成了传统化石能源的使用成本急剧上升。人们 寻求更多缓解或解决能源危机的途径,一些更有效利用传统化石能源的方法以及 清