三相光伏并网逆变器.doc
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三相光伏并网逆变器,摘要太阳能作为一种无污染的可再生能源是未来人类能源利用的重要来源。光伏并网发电作为太阳能应用的主流方向越来越受到人们的重视。本文的研究基础是建立在之上，为了使电网的供电质量和能力有所提高，将有源滤波、无功补偿与光伏并网发电相结合，既可以提供有功电能，同时又可以抑制谐波、补偿无功功率。在三相光伏并网系统...
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摘 要
太阳能作为一种无污染的可再生能源是未来人类能源利用的重要来源。光伏并网发电作为太阳能应用的主流方向越来越受到人们的重视。
本文的研究基础是建立在三相光伏并网逆变器之上，为了使电网的供电质量和能力有所提高，将有源滤波、无功补偿与光伏并网发电相结合，既可以提供有功电能，同时又可以抑制谐波、补偿无功功率。
在三相光伏并网系统中，主要研究了光伏并网的两级式拓扑结构、最大功率点跟踪算法、谐波抑制和无功补偿等，其中本文的研究重点是谐波抑制和无功补偿，目的都是为了能够实现光伏发电与无功补偿的统一控制。
通过分析光伏电池的特性曲线与温度、辐照度之间的关系，验证了光伏电池具有非线性输出的结论。在比较和分析了几种常用的最大功率点跟踪算法基础上，选用电导增量法作为本文的最大功率点跟踪算法，稳定性明显优于其它算法。
将光伏并网发电系统逆变主电路的结构特点与有源电力滤波器的工作原理相结合，提出了将光伏发电与谐波抑制、无功补偿统一控制的思想，并详细分析了其控制方法。基于空间矢量脉冲宽度调制的补偿电流跟踪控制算法，推导出了同步旋转dq坐标系的参考电流的状态空间方程及离散化控制方程。整个光伏并网系统既向电网输出有功功率，又可作有源电力滤波器抑制谐波、补偿无功。
本文最后分析了并网系统的孤岛现象和孤岛检测盲区存在的原因，并介绍了一种基于dq变换和电压正反馈原理相结合的孤岛检测方法。通过对逆变器端输出电流和负载端电压的变化判断系统是否进入孤岛状态。
本文所提方案全部进行仿真分析，结果表明上述方案的可行性。
关键词：光伏并网发电；最大功率点跟踪；有源滤波器；孤岛检测
Abstract
The solar energy is used as a kind of efficiently renewable energy, the important source of the normal regulations energy of future. Currently, the technique of photovoltaic(PV) grid-connected generates electricity among them have become the most prospected, turn to the main form of the solar application.
This paper adopted the three-phase PV grid system, is based on the main grid circuit, in which a PV generation is with reactive power compensation and harmonic restrain. In this way, PV grid-connected systems can provided not only active power, but also reactive power, which improving the quality of power supplying and capacity.
Under the control of PV grid-connected systems the topology of PV power generation, solar maximum power point tracking(MPPT), harmonic and active current detection, the instantaneous reactive power compensation and harmonic restrain technique are proposed. And those operation principles and math models are further analyzed of the unified control of the PV grid-connected and reactive power compensation.
According to the V-I characteristics of various temperature and various irradiance, the output of solar cell has a strong non-linear. In PV grid-connected system, do further researching of MPPT methods, analyze advantages and disadvantages of various methods, choose incremental conductance as this MPPT algorithm.
Based on the active power filter(APF) theory, the control strategy is proposed for a PV grid-connected system, in which a PV generation with reactive power and uniform grid-connected control. The compensation current tracking and controlling algorithm based on SVPWM are derived from the synchronous rotating dq reference frame and discrete state space equation. PV grid-connected system can be used to provide active power to the grid, but also for reactive power compensation, harmonic restrain for APF.
Islanding of PV grid-connected system and the reason for the existence of dead zone are analyzed, and the active frequency drift method is proposed. The paper introduces a kind of island detection method which combining dq transformation and positive feedback principle. The island is judged by the change of the load voltage and inverter output current waveforms.
The simulink model of PV grid-connected and APF system are built with SimPowerSystem Blockset and simulink in MATLAB/SIMULINK. The simulation results show the feasibility and precision of the proposed approach.
Key words: PV grid-connected; Maximum power point tracking; Active power filter; Islanding detection
目 录
摘要 I
ABSTRACT III
目录 V
Contents VII
第1章 绪论 1
1.1 课题研究背景与意义 1
1.2 国内外光伏发电发展现状及前景 1
1.3 光伏发电并网逆变系统的概述 2
1.3.1 光伏发电系统的原理和组成 3
1.3.2 光伏发电系统的分类与介绍 3
1.3.3 光伏发电系统的特点 3
1.4 本文研究的主要内容 4
第2章 光伏电池最大功率点跟踪技术研究 6
2.1 光伏电池的工作原理 6
2.2 光伏电池的模型和特性 6
2.2.1 光伏电池的等效模型 6
2.2.2 光伏电池的电气特性 8
2.3 光伏并网逆变系统的拓扑结构 10
2.4 典型的DC/DC变换电路 12
2.5 基于DC/DC变换器的MPPT算法研究 13
2.5.1 恒电压跟踪法 14
2.5.2 扰动观察法 15
2.5.3 电导增量法 16
2.5.4 模糊控制法 18
2.5.5 其它MPPT方法 18
2.6 本章小结 18
第3章 逆变器的控制策略 19
3.1 并网逆变器控制方式 19
3.2 逆变器输出电流的控制方式 19
3.2.1 滞环电流瞬时比较方式 20
3.2.2 定时电流瞬时比较方式 20
3.2.3 SPWM电流跟踪方式 21
3.3 SVPWM控制方式 21
3.3.1 SPWM调制方式和SVPWM调制方式比较 21
3.3.2 SVPWM的基本原理 22-..
太阳能作为一种无污染的可再生能源是未来人类能源利用的重要来源。光伏并网发电作为太阳能应用的主流方向越来越受到人们的重视。
本文的研究基础是建立在三相光伏并网逆变器之上，为了使电网的供电质量和能力有所提高，将有源滤波、无功补偿与光伏并网发电相结合，既可以提供有功电能，同时又可以抑制谐波、补偿无功功率。
在三相光伏并网系统中，主要研究了光伏并网的两级式拓扑结构、最大功率点跟踪算法、谐波抑制和无功补偿等，其中本文的研究重点是谐波抑制和无功补偿，目的都是为了能够实现光伏发电与无功补偿的统一控制。
通过分析光伏电池的特性曲线与温度、辐照度之间的关系，验证了光伏电池具有非线性输出的结论。在比较和分析了几种常用的最大功率点跟踪算法基础上，选用电导增量法作为本文的最大功率点跟踪算法，稳定性明显优于其它算法。
将光伏并网发电系统逆变主电路的结构特点与有源电力滤波器的工作原理相结合，提出了将光伏发电与谐波抑制、无功补偿统一控制的思想，并详细分析了其控制方法。基于空间矢量脉冲宽度调制的补偿电流跟踪控制算法，推导出了同步旋转dq坐标系的参考电流的状态空间方程及离散化控制方程。整个光伏并网系统既向电网输出有功功率，又可作有源电力滤波器抑制谐波、补偿无功。
本文最后分析了并网系统的孤岛现象和孤岛检测盲区存在的原因，并介绍了一种基于dq变换和电压正反馈原理相结合的孤岛检测方法。通过对逆变器端输出电流和负载端电压的变化判断系统是否进入孤岛状态。
本文所提方案全部进行仿真分析，结果表明上述方案的可行性。
关键词：光伏并网发电；最大功率点跟踪；有源滤波器；孤岛检测
Abstract
The solar energy is used as a kind of efficiently renewable energy, the important source of the normal regulations energy of future. Currently, the technique of photovoltaic(PV) grid-connected generates electricity among them have become the most prospected, turn to the main form of the solar application.
This paper adopted the three-phase PV grid system, is based on the main grid circuit, in which a PV generation is with reactive power compensation and harmonic restrain. In this way, PV grid-connected systems can provided not only active power, but also reactive power, which improving the quality of power supplying and capacity.
Under the control of PV grid-connected systems the topology of PV power generation, solar maximum power point tracking(MPPT), harmonic and active current detection, the instantaneous reactive power compensation and harmonic restrain technique are proposed. And those operation principles and math models are further analyzed of the unified control of the PV grid-connected and reactive power compensation.
According to the V-I characteristics of various temperature and various irradiance, the output of solar cell has a strong non-linear. In PV grid-connected system, do further researching of MPPT methods, analyze advantages and disadvantages of various methods, choose incremental conductance as this MPPT algorithm.
Based on the active power filter(APF) theory, the control strategy is proposed for a PV grid-connected system, in which a PV generation with reactive power and uniform grid-connected control. The compensation current tracking and controlling algorithm based on SVPWM are derived from the synchronous rotating dq reference frame and discrete state space equation. PV grid-connected system can be used to provide active power to the grid, but also for reactive power compensation, harmonic restrain for APF.
Islanding of PV grid-connected system and the reason for the existence of dead zone are analyzed, and the active frequency drift method is proposed. The paper introduces a kind of island detection method which combining dq transformation and positive feedback principle. The island is judged by the change of the load voltage and inverter output current waveforms.
The simulink model of PV grid-connected and APF system are built with SimPowerSystem Blockset and simulink in MATLAB/SIMULINK. The simulation results show the feasibility and precision of the proposed approach.
Key words: PV grid-connected; Maximum power point tracking; Active power filter; Islanding detection
目 录
摘要 I
ABSTRACT III
目录 V
Contents VII
第1章 绪论 1
1.1 课题研究背景与意义 1
1.2 国内外光伏发电发展现状及前景 1
1.3 光伏发电并网逆变系统的概述 2
1.3.1 光伏发电系统的原理和组成 3
1.3.2 光伏发电系统的分类与介绍 3
1.3.3 光伏发电系统的特点 3
1.4 本文研究的主要内容 4
第2章 光伏电池最大功率点跟踪技术研究 6
2.1 光伏电池的工作原理 6
2.2 光伏电池的模型和特性 6
2.2.1 光伏电池的等效模型 6
2.2.2 光伏电池的电气特性 8
2.3 光伏并网逆变系统的拓扑结构 10
2.4 典型的DC/DC变换电路 12
2.5 基于DC/DC变换器的MPPT算法研究 13
2.5.1 恒电压跟踪法 14
2.5.2 扰动观察法 15
2.5.3 电导增量法 16
2.5.4 模糊控制法 18
2.5.5 其它MPPT方法 18
2.6 本章小结 18
第3章 逆变器的控制策略 19
3.1 并网逆变器控制方式 19
3.2 逆变器输出电流的控制方式 19
3.2.1 滞环电流瞬时比较方式 20
3.2.2 定时电流瞬时比较方式 20
3.2.3 SPWM电流跟踪方式 21
3.3 SVPWM控制方式 21
3.3.1 SPWM调制方式和SVPWM调制方式比较 21
3.3.2 SVPWM的基本原理 22-..
