摘要：并网逆变器作为分布式并网发电系统核心，起着举足轻重的作用。无论是 结构还是控制技术，都直接影响着系统的性能和稳定。本文即针对分布式并网发 电系统，着重于并网逆变技术做了如下研究： 75424

首先，简要总结智能电网与分布式发电系统的背景，介绍光伏并网发电主要 架构以及并网逆变器拓扑结构、控制策略。其次从光伏并网逆变器拓扑结构方面 分析传统并网逆变器优缺点，并重点在无变压器结构光伏并网逆变器抑制共模漏 电流的角度分析各新型拓扑结构工作原理与性能，提出采用带交流旁路结构的无 变压器光伏并网逆变器作为本文主要研究对象。再从光伏并网逆变器滤波结构角 度，建立 LCL 型光伏并网系统控制与数学模型，从无源阻尼、有源阻尼多种角度 分析各并网控制策略与稳定性，提出一种基于无源阻尼改进式可抑制电网电压背 景谐波的并网控制策略，通过仿真验证，最终给出基于无源阻尼改进式可抑制电 网电压背景谐波的并网控制整体方案。最后对本文所完成工作给出了结论。 

毕业论文关键词：分布式发电，并网逆变器，背景谐波，LCL 滤波 

Abstract: Grid inverter as the core of distributed power generation system, plays an important role。 Whether the structure or control, directly affect the performance and stability of the system。 This article is for distributed power generation system, focusing on grid inverter technology made the following studies:

First, a brief summary of the background and the smart grid distributed generation systems, photovoltaic power generation introduces major architectural and grid-connected inverter topology, control strategy。 Second, from the aspect of photovoltaic grid inverter topology analysis of the traditional grid inverter strengths and weaknesses, and focus on the structure without transformer PV grid-connected inverter suppress common mode leakage current angle analysis of the topology of the new works and performance, proposed use with AC bypass structure transformerless PV grid-connected inverter as the main object of this study。 And then from the PV grid-connected inverter filter structure point of view, the establishment of LCL Grid-control system and mathematical model from passive damping, active damping variety of angles and analysis of the network and stability control strategy is proposed based on no source improved damping formula suppressed the background grid voltage harmonics and network control strategy through simulation, and ultimately given overall control scheme based on the passive damping improved formula inhibit background grid voltage harmonics of the grid。 Finally, the work done is given herein conclusions。

Keywords: distributed generation, grid-connected inverter, harmonic background, LCL filter

目 录

1 绪论 5

1。1 地球能源现状与发展趋势 5

1。2 智能电网与分布式发电 5

1。3 并网逆变器研究现状 7

2 光伏并网逆变器拓扑结构 9

2。1 传统的并网逆变器拓扑结构 9

2。2 新型无变压器并网逆变器拓扑结构 9

3 分布式发电系统并网逆变控制策略研究 12

3。1 LCL 型并网逆变器滤波结构分析及数学模型 13

3。2 LCL 型并网逆变器阻尼谐振策略与稳定性分析 15

3。3 基于无源阻尼改进带电网背景谐波抑制的并网策略