軟開關技術在變頻器中的應用

電子機電論文編號:JD300       論文字數:31061,頁數:65

目 錄

摘要..................................................................Ⅰ abstract.............................................................Ⅱ
第1章  緒論..........................................................1    

1.1 課題研究背景與研究目的..............................................1    

1.2 變頻器的原理與發展....................................................2
        1.2.1 變頻器的構成.................................................2
        1.2.2 變頻器的發展歷程.............................................3
1.3 現代逆變技術的發展......................................................3

1.3.1 現代逆變系統的基本組成................................................4
1.3.2 電力電子開關器件的發展................................................4
1.3.3 逆變中PWM技術.......................................................5

1.4 傳統PWM硬開關逆變器存在的問題...........................................6
1.5 軟開關變換電路的提出與發展..............................................6
1.6 dsp 控制的簡介........................................................7
1.7 主要任務與內容........................................................7
第2章  軟開關諧振變換技術的基本原理及其發展...................................9
2.1 軟開關的基本描述.......................................................9

2.1.1軟開關的種類.........................................................9

2.1.2軟開關的基本原理及優點................................................10
2.2 軟開關諧振變換技術....................................................11

2.2.1諧振的基本原理.......................................................11

2.2.2準諧振與多諧振變換器..................................................13
2.2.3零電流開關(ZCS)與零電壓開關(ZVS)變換器................................14

2.3 直流環節諧振型逆變器..................................................15
2.3.1諧振直流環節型逆變器(RDCLI)及其控制策略...............................15

2.3.2并聯諧振直流環節逆變器的改進拓撲.......................................17
2.4 本章小結............................................................17

第3章  DSP的結構與功能...................................................18
3.1 引言...............................................................18
3.2 TMS320LF2407芯片概述................................................18
3.3 DSP數字控制器的硬件平臺...............................................20
3.4 DSP實現A/D轉換的原理.................................................22
3.5 本章小結............................................................22
第4章  三相軟開關PWM變頻器逆變原理與實現....................................23
4.1 三相PWM逆變器主電路原理...............................................23
4.2 工作模式及其數學分析..................................................23
4.3 系統總體結構.........................................................29

4.4 變頻器PWM調制原理....................................................30   

4.4.1 PWM變頻技術.......................................................30   

4.4.2 正弦波脈寬調制原理................................................30
   4.4.3 SPWM規則采樣法................................................30
4.5 PWM變頻器的控制方法.................................................31

4.5.1 選用三角波調制方式的局限性..........................................31

4.5.2 SAPWM基本原理....................................................32

4.5.3 PWM變頻器的控制方式................................................33
4.6 ZVS的控制及參數分析..................................................35
4.6.1 電流極性判別.......................................................35
4.6.2 諧振環節vc1、vc2、vs時序設計........................................36
4.6.3諧振電感和緩沖電容的作用..............................................37
    4.7  電機正反轉控制分析...............................................37
4.8 本章小結.............................................................38
第5章  軟開關變頻器的軟件設計..............................................39
5.1引言.................................................................39

5.2系統軟件流程圖........................................................39

5.3各功能模塊流程圖及簡要介紹.............................................40
5.3.1 SPWM模塊.........................................................40

5.3.2數據采集A/D模塊.....................................................42

5.3.3數制轉換模塊........................................................42

5.3.4數字PID模塊........................................................44

5.3.5 RSC模塊...........................................................45
5.4 電機正反轉控制算法流程圖..............................................47
5.5本章小結.............................................................47
第6章  仿真與實驗分析 ...................................................48
6.1 引言...............................................................48
6.2 各模塊仿真圖........................................................48
6.2.1 諧振部分仿真......................................................48
6.2.2 整流輸出波形......................................................50
6.2.3 PWM逆變波形.......................................................51
6.3 仿真結果與分析.......................................................52
6.3.1硬開關變頻器的仿真..................................................52
6.3.2軟開關變頻器的仿真..................................................53
6.4本章小結.............................................................54
結束語..................................................................55
參考文獻................................................................56
致謝....................................................................58

摘 要：21世紀的電力電子產品應該是無公害或低公害的“綠色” 產品。因此如何在變頻應用領域實現這一目標具有十分重要的現實意義。本研究課題的目標是三相軟開關變頻器DC直流環節的并聯諧振，實現逆變橋上每個功率開關器件以零電壓方式開通，達到軟開關的目的。并以TI公司的TMS320LF2407型DSP為核心構成整個系統的控制電路，進行異步電機新型控制策略的研究。
論文首先闡述了SAPWM模式的原理以及DC—AC逆變器中的軟開關諧振變換技術，重點討論了本研究的軟開關拓撲結構及其控制策略，并對其工作過程中的9個模式作了詳細的數學解析。本研究的實驗裝置包括主電路和控制電路。主電路采用IMP模塊來實現DC—AC逆變；控制電路是以TMS320LF2407 DSP評估板為核心擴展出的印刷線路板，主要生成各種觸發信號、保護信號以及實現變頻器的部分功能。在逆變器正常工作的基礎上對中間諧振環節，即零電壓開關電路進行了初步的實驗測試，討論了相關參數的設定及其對于諧振的影響，為進一步開發高性能三相軟開關雙PWM變頻器打下了基礎。
關鍵字：變頻器；并聯諧振直流環節；PWM技術；DSP；軟開關技術

Abstract：In the 21st century，the power electronic products ought be“green”，whose pollution to environment is none or very low. So, it is very important significance about how to achieve this target in inverter application field. The aim of this research is to use DC link parallel resonance three---phase soft---switching technique to realize in inverter. In addition, with selecting TI Company’s DSP TMS320LF2407 as controller, the new strategy toward induction motor is studied.
In this thesis SAPWM theory and the soft---switching technology in DC---AC inverter are first described. As the key of this thesis, the soft---switching topology proposed by this project is discussed in detail, including the mathematics analysis on its working principles which can be divided into 9 modes. Two part of the hardware used in the experiment are main circuit and the control circuit. IPM is the kernel of the main circuit. The control circuit is composed of the PCB grounded on TMS320LF2407 DSP and its eva luation module.
The ZVS circuit in the inverter is preliminarily tested in experiment and the influence of the relevant parameters on the this dissertation in order to further develop the high per for three---phase soft---switching double PWM inverter.
Keywords: Inverter； Parallel Resonance DC link；PWM(Pulse-width Modulation) technology；DSP（Digital Signal Processing）；Soft---Switching