【作者】 李连玉；

【导师】 崔玉龙；

【作者基本信息】 北京化工大学 ， 控制科学与工程， 2012， 硕士

【摘要】 光伏发电是替代化石能源的一种最理想的方式，但较高的光伏发电成本成为制约其推广应用的主要因素。光伏发电逆变控制器是将光伏电池输出的直流电能转换为交流电能的装置，在能量转换和利用的过程中也产生了大量的能量损耗，增加了发电成本。因此，研究高效率光伏发电逆变控制器的拓扑及控制方法具有重要的理论意义和应用价值。本文通过对光伏电池工程化数学模型的建模及仿真，研究了光伏电池的电能输出特性；分析了基于功率电压斜率（dP/dV）曲线的变步长MPPT方法的工作原理和控制效果受光照强度影响的缺点，提出了一种改进型变步长MPPT方法，设计了3种不同步长的变步长控制策略，给出了变步长判断参数的确定方法；分析了光伏逆变器的拓扑结构及调制方法，采用了两级型多支路并联结构的设计方案，设计了2KW单相光伏逆变器的具体控制方法及电路参数；在MATLAB/Simulink中建立了2KW单相光伏逆变系统的仿真模型，分析了逆变器的电能利用率及输出电压的控制效果。仿真结果表明：改进型变步长MPPT方法的控制效果基本不受光伏电池光照强度的影响，三种步长的控制策略加快了光伏电池的MPPT速度，提升了稳态输出功率；两级型多支路并联结构的光伏逆变器，可以避免并联光伏电池组件间失配引起的功率损失，最大化利用了光伏电池输出电能，双闭环控制的逆变器输出电压稳态误差小，动态响应快，这种逆变器结构及控制方法为光伏发电与城市建筑一体化应用提供了一个新的思路。更多还原

【Abstract】 Photovoltaic(PV) power generation is the ideal alternative to fossil fuels,however, the higher cost of photovoltaic power than conventional powerrestricts its application. PV power inverter is a device in which DC output ofPV cells can be converted to AC electricity, and in the process of energyconversion and utilization, a large amount of energy is lost, which increasedthe cost of power generation. Therefore, the research of topological structureand control method of high-efficiency PV power inverters has significanttheoretical significance and application value.Based on the simulation of the engineered mathematical model of the PVcells, the power output characteristics of PV cells was studied; a new variablestep size method based on (dP/dV)/P was proposed after the analysis of theprinciple and stability of variable step size method based on dP/dV, and avariable step size control strategy with three kinds of step size was designedand the determination method its parameters was shown out; after the analysisof the advantages and disadvantages of different categories of topologies ofPV inverters, the control method and circuit parameters of2KW single-phasePV inverter was designed, the power utilization and control effect of outputvoltage of the inverter was analyzed in the simulation model built in MATLAB/Simulink.The simulation results show that the control effect of the modifiedvariable step size MPPT method was independent of the impact of lightintensity of PV cells, the strategy with three step sizes accelerated the speed ofthe MPPT of PV cells, and enhanced the steady-state output power; the PVinverter with multidroped parallel structure avoided the power loss when themismatch happened between the parallel components of PV cells, maximizedthe use of the output power of PV cells, and its output voltage had smallsteady-state error and fast dynamic response, so this structure and controlmethods of inverters provided a new way of PV power generation and urbanbuilding integrated applications更多还原