摘 要
太陽能作為一種無污染的可再生能源是未來人類能源利用的重要來源。光伏并網(wǎng)發(fā)電作為太陽能應用的主流方向越來越受到人們的重視。
本文的研究基礎(chǔ)是建立在三相光伏并網(wǎng)逆變器之上，為了使電網(wǎng)的供電質(zhì)量和能力有所提高，將有源濾波、無功補償與光伏并網(wǎng)發(fā)電相結(jié)合，既可以提供有功電能，同時又可以抑制諧波、補償無功功率。
在三相光伏并網(wǎng)系統(tǒng)中，主要研究了光伏并網(wǎng)的兩級式拓撲結(jié)構(gòu)、最大功率點跟蹤算法、諧波抑制和無功補償?shù)?，其中本文的研究重點是諧波抑制和無功補償，目的都是為了能夠?qū)崿F(xiàn)光伏發(fā)電與無功補償?shù)慕y(tǒng)一控制。
通過分析光伏電池的特性曲線與溫度、輻照度之間的關(guān)系，驗證了光伏電池具有非線性輸出的結(jié)論。在比較和分析了幾種常用的最大功率點跟蹤算法基礎(chǔ)上，選用電導增量法作為本文的最大功率點跟蹤算法，穩(wěn)定性明顯優(yōu)于其它算法。
將光伏并網(wǎng)發(fā)電系統(tǒng)逆變主電路的結(jié)構(gòu)特點與有源電力濾波器的工作原理相結(jié)合，提出了將光伏發(fā)電與諧波抑制、無功補償統(tǒng)一控制的思想，并詳細分析了其控制方法?；诳臻g矢量脈沖寬度調(diào)制的補償電流跟蹤控制算法，推導出了同步旋轉(zhuǎn)dq坐標系的參考電流的狀態(tài)空間方程及離散化控制方程。整個光伏并網(wǎng)系統(tǒng)既向電網(wǎng)輸出有功功率，又可作有源電力濾波器抑制諧波、補償無功。
本文最后分析了并網(wǎng)系統(tǒng)的孤島現(xiàn)象和孤島檢測盲區(qū)存在的原因，并介紹了一種基于dq變換和電壓正反饋原理相結(jié)合的孤島檢測方法。通過對逆變器端輸出電流和負載端電壓的變化判斷系統(tǒng)是否進入孤島狀態(tài)。
本文所提方案全部進行仿真分析，結(jié)果表明上述方案的可行性。

關(guān)鍵詞：光伏并網(wǎng)發(fā)電；最大功率點跟蹤；有源濾波器；孤島檢測


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 錄
摘要 I
ABSTRACT III
目錄 V
Contents VII
第1章 緒論 1
1.1 課題研究背景與意義 1
1.2 國內(nèi)外光伏發(fā)電發(fā)展現(xiàn)狀及前景 1
1.3 光伏發(fā)電并網(wǎng)逆變系統(tǒng)的概述 2
1.3.1 光伏發(fā)電系統(tǒng)的原理和組成 3
1.3.2 光伏發(fā)電系統(tǒng)的分類與介紹 3
1.3.3 光伏發(fā)電系統(tǒng)的特點 3
1.4 本文研究的主要內(nèi)容 4
第2章 光伏電池最大功率點跟蹤技術(shù)研究 6
2.1 光伏電池的工作原理 6
2.2 光伏電池的模型和特性 6
2.2.1 光伏電池的等效模型 6
2.2.2 光伏電池的電氣特性 8
2.3 光伏并網(wǎng)逆變系統(tǒng)的拓撲結(jié)構(gòu) 10
2.4 典型的DC/DC變換電路 12
2.5 基于DC/DC變換器的MPPT算法研究 13
2.5.1 恒電壓跟蹤法 14
2.5.2 擾動觀察法 15
2.5.3 電導增量法 16
2.5.4 模糊控制法 18
2.5.5 其它MPPT方法 18
2.6 本章小結(jié) 18
第3章 逆變器的控制策略 19
3.1 并網(wǎng)逆變器控制方式 19
3.2 逆變器輸出電流的控制方式 19
3.2.1 滯環(huán)電流瞬時比較方式 20
3.2.2 定時電流瞬時比較方式 20
3.2.3 SPWM電流跟蹤方式 21
3.3 SVPWM控制方式 21
3.3.1 SPWM調(diào)制方式和SVPWM調(diào)制方式比較 21
3.3.2 SVPWM的基本原理 22-..