【作者】 张梅；

【导师】 毛承雄； 王丹；

【作者基本信息】 华中科技大学 ， 电气工程， 2022， 硕士

【摘要】 为了有效应对能源危机和环境问题,我国提出构建新型电力系统,大力发展可再生能源发电。可再生能源发电往往具有间歇性和波动性,大规模接入后会增加电力系统能量平衡控制的难度。此外大量直流负荷和分布式单元接入,使得配电网形态向交直流混联网络发生转变,故传统配电网需在可靠性、可控性及智能化等方面进行提升。能量路由器因具有为可再生能源提供接口且控制功能丰富等显著优点,成为配电网智能化升级的重要选择。本文对应用于配电网的能量路由器展开研究,具体如下:首先,将结构简单可靠性高的工频变压器和控制功能丰富的电力电子装置相结合,提出一种融合工频变压器的多端口能量路由器(Multi-port Energy Router Based on Line Frequency Transformer,MER-LFT),它具有交直流混合配电、电能变换、能量管理及电能质量综合治理等功能。MER-LFT利用工频变压器可以减少电力电子器件的使用数量,有效降低经济成本,然后对MER-LFT的主电路拓扑结构进行分析,并对拓扑结构中主要电力电子换流器数学建模,最后对MER-LFT的主要参数进行设计。其次,对MER-LFT的工作模式进行分析,包括并网及孤网模式。为保证MERLFT在不同模式下正常运行,本文提出双层控制策略。下层控制策略为电力电子换流器的具体控制策略,上层控制策略则是指MER-LFT不同工作模式切换及能量管理策略。在Matlab/Simulink上搭建MER-LFT的仿真模型,对其进行稳态、暂态及能量管理仿真,验证了MER-LFT的功能及所提控制策略的有效性。最后,针对分布式发电单元和非线性负荷接入给配电网带来的电能质量问题,本文在MER-LFT上设置了一个电能质量治理端口对其进行综合治理。首先对该端口的串并联混合电能质量治理模块的运行原理和控制策略进行分析。然后基于MER-LFT仿真模型,对常见的工况进行仿真,验证了该端口能够实现电能质量问题综合治理。最后基于上述研究研制出一台容量为100 k VA的MER-LFT试验样机,对其稳态、暂态和电能质量治理功能进行试验验证,验证了该样机的性能和电能质量治理功能。更多还原

【Abstract】 In order to effectively deal with the current energy crisis and environmental problems,China proposes to build a new power system and vigorously develop renewable energy generation.The generation of renewable energy is often intermittent and volatile,which will increase the difficulty of energy balance control of power system after large-scale access.In addition,a large number of DC loads and the access of distributed units make the form of distribution network change to AC-DC hybrid network,so it is necessary to improve the reliability,controllability and intelligence of traditional distribution network.Energy router is an important choice for intelligent upgrade of distribution network due to its obvious advantages of providing interface for renewable energy and rich control functions.In this thesis,the energy router used in distribution network is studied as follows:First of all,this thesis effectively combines line frequency transformers which have simple structure and high reliability and power electronic devices which have rich control functions.A multi-port energy router based on line frequency transformer(MER-LFT)is proposed.It has the functions of AC/DC hybrid power distribution,energy conversion,energy management and comprehensive power quality control.Making use of Line frequency transformers,MER-LFT can reduce the number of power electronic devices and effectively reduce the economic cost.Then,the main circuit topology of MER-LFT is analyzed,the mathematical models of the main converters in the topology are established,finally,the main parameters of MER-LFT are designed.Secondly,the thesis analyzes the working mode of MER-LFT,including gridconnected and solitary grid.In order to ensure the normal operation of MER-LFT in different modes,a two-layer control strategy for MER-LFT is proposed.The lower control strategy refers to the control strategy of power electronic converters,and the upper control strategy refers to control different mode switching and energy management.The simulation model of MER-LFT was built on Matlab/Simulink,and the steady-state simulation,transient simulation and energy management simulation were carried out to verify the functions of MER-LFT and the effectiveness of the proposed control strategy.Finally,a power quality control port is set up on MER-LFT to comprehensively control the power quality problems brought by the access of distributed generation units and nonlinear loads to the distribution network.Firstly,the principle of operation and control strategy of the series and parallel hybrid power quality control module of the port are analyzed.Then,on the basis of the simulation model built above,the common working conditions are simulated to verify that the port can achieve comprehensive treatment of power quality problems.In view of the above research,a 100 k VA capacity MER-LFT test prototype was developed to verify its steady-state,transient and power quality control functions,the results verify the performance and power quality control function of the prototype.更多还原