节点文献
大功率光伏并网逆变系统研究
Research on High Power Photovoltaic Grid-connected Inverting System
【作者】 马亮；
【导师】 郑琼林；
【作者基本信息】 北京交通大学 ， 电力电子与电力传动， 2012， 博士
【摘要】 光伏并网发电因其具有丰富的太阳能资源、清洁无污染、安装维护简单、可结合建筑进行资源利用等优点,是21世纪最重要的能源之一。然而,大功率光伏并网系统的设计及控制技术还存在一些问题,极大制约了光伏产业的发展。因此,本文围绕三相光伏并网逆变系统的设计及控制策略进行了分析研究,并通过仿真和实验验证了理论研究的正确性。本文研究了电网不平衡对光伏并网逆变器的影响,介绍了基于统一模型的三种不平衡控制目标。研究了二次谐波滤除法,提出了正、负序滤波器法进行电网不平衡分量提取策略。系统仿真对此进行了验证。建立了LCL滤波器模型,研究了四种情况下LCL滤波系统稳定性,给出了LCL滤波器的工程设计原则,并通过100kW并网逆变器滤波器的设计进行了验证。提出了滤波阻尼法的虚拟阻尼控制策略,并给出其实验验证。介绍了低电压故障对光伏并网系统的影响,研究了双环控制及无功控制低电压穿越策略。提出了非线性低电压穿越控制策略,并验证了此策略下系统直流电容的设计。给出了大规模光伏并网系统设计原则,研究了5种光伏系统运行模式,在直流母线并联拓扑的基础上提出了针对效率优化的N+1控制、穷举法和动态均分法三种集群控制策略,并验证其先进性。提出并设计630kVA交流能量互馈式大功率并网逆变器全自动测试系统,设计其630kVA整流器及模块化4U控制系统。以本文生产的3kW-500kW全系列单级式光伏并网逆变器中500kW为例验证测试系统性能,并在此测试系统完成了全部“金太阳”电性能测试。
【Abstract】 Photovoltaic grid-connected power generation is considered to be the most important source of energy in21st century due to its superiorities in containing abundant solar energy resource, being clean, easy to install and maintain, with building-integrated ability for solar energy utilization, etc. However, the system design and core control technologies of high power photovoltaic grid-connected system still contain some problems, which significantly restrict further development of photovoltaic industry. Therefore, this dissertation gives theoretical study on topology design and control technologies of three phase photovoltaic grid-connected inverting system. Simulations and experiments demonstrate the correctness of the research results.Influence to grid-connected inverter caused by grid unbalance has been discussed, the unbalance control strategies based on the unified inverter model has been researched. Second order harmonic filtering method has been discussed, PSF and NSF method for extracting unbalance electromotive force is proposed. Simulation and experiment proved its correctness.Model of LCL filter has been set up, stability analysis in four cases has been discussed, engineering design principle and the step of LCL filter is proposed, and100kW LCL filter design has proved its correctness. Filtering damping method virtual damping resistor control strategy is proposed, its design and validation has been given out.Influence to photovoltaic grid-connected system caused by low voltage fault has been discussed, dual loop control and reactive power generation low voltage ride through strategies have been given out. Nonlinear low voltage ride through control strategies is proposed, its DC capicatance design adopting the strategy has been validated.Design principles of large scale photovoltaic grid-connected system is proposed, five system operation modes have been researched, based on the common DC bus topology, N+1method, infinite enumerative method, dynamic equational method group control strategies aimed at efficiency optimization have been proposed, their advantages have been validated.630kVA reciprocal power-fed full automatic high power grid-connected inverter test system is proposed,630kVA rectifier and modularized4U control system design have been given out. In3kW-500kW series single stage photovoltaic grid-connected inverters designed by the dissertation,500kW inverter has been used to validate performance of the test system, and it has been also used to performe "Golden Sun" electric performance test on the test system.