【正文】
start start principle in this foundation, gave has limited flows the soft start, the voltage pitch starts, the torque control started, torque Canada kicked the control to start, voltage control start and so on several start methods and diagram of curves, Has separately carried on the explanation to each kind of start way good and bad points, has obtained the quite good start way is the voltage control starts, the torque control start and torque Canada kicks the control start. Draws support from the Matlab/Simulink toolbox and the electrical system module storehouse once more (Power System Blockset) conducts the simulation research to the alternating current machine soft start process, Established the threephase AC voltage link module, the synchronized link module, the pulse has had the module, the threephase AC accent pressed the module, the electrical machinery and the survey module, the current feedback, link seal modules and so on start control and anxious link, Has constructed the integrity simulation system model, and has analyzed each module establishment process, the parameter hypothesis and the basic function, has given the simulation result, and has carried on the analysis to the result, the confirmation. Finally induces the summary at present the soft start technology characteristic, pointed out the present soft start product development should consider factor as well as soft start development, soft start energy conservation, and did to the frequency conversion velocity modulation discussed shallowly caused it to carry on the parison with the soft start to obtain the soft start good and bad points. KEKWORDS: AC motor, Softstarting, simulating, matlab, energy saving III 目 錄 摘 要 .................................................................... I ABSTRACT ................................................................ II 1 交流軟啟動(dòng)概述 ......................................................... 1 交流電機(jī)啟動(dòng)方式簡(jiǎn)介 ............................................. 1 交流電機(jī)直接啟動(dòng)的弊端及限制條件 ........................... 1 傳統(tǒng)的啟動(dòng)技術(shù) ............................................. 2 晶閘管軟啟動(dòng)技術(shù) ........................................... 3 交流電機(jī)啟動(dòng)方式選擇 ....................................... 3 型異步電動(dòng)機(jī)減壓?jiǎn)?dòng)方法 ......................................... 4 定子串電阻或電抗器減壓?jiǎn)?dòng) ................................. 4 自耦變壓器降壓?jiǎn)?dòng) ......................................... 5 星形-三角形( Y-△)啟動(dòng) .................................. 7 變頻軟啟動(dòng)的原理及應(yīng)用 ........................................... 7 變頻軟啟動(dòng)的基本結(jié)構(gòu) ....................................... 8 變頻軟啟動(dòng)的工作原理 ....................................... 8 變頻軟啟動(dòng)與 軟啟動(dòng)的比較 ........................................ 10 2 晶閘管軟啟動(dòng)技術(shù)原理與節(jié)能 ............................................ 11 晶閘管軟啟動(dòng)技術(shù)原理 ............................................. 11 軟啟動(dòng)節(jié)能技術(shù)及原理與軟啟 動(dòng)智能化發(fā)展 ........................... 14 異步電動(dòng)機(jī)中的損耗 ........................................ 14 異步電動(dòng)機(jī)的節(jié)能原理 ...................................... 14 軟啟動(dòng)智能化發(fā)展 .......................................... 16 軟啟動(dòng)行業(yè)現(xiàn)狀及發(fā)展方向 ......................................... 17 軟啟動(dòng)行業(yè)現(xiàn)狀 ............................................ 17 軟啟動(dòng)的發(fā)展方向 .......................................... 17 3 MATLAB/SIMULINK 工具箱的簡(jiǎn)介 ........................................... 19 MATLAB 簡(jiǎn)介 ....................................................... 19 SIMULINK 工具箱簡(jiǎn)介: .............................................. 21 電力系統(tǒng)模型庫(kù)( SIMPOWERSYSTERM)工具箱簡(jiǎn)介 ......................... 23 4 交流電機(jī)軟啟動(dòng)系統(tǒng)仿真建模 ............................................ 24 交流電動(dòng)機(jī)數(shù)學(xué)模型 ............................................... 24 異步電動(dòng)機(jī)在α ,β,0 坐標(biāo)系統(tǒng)下的數(shù)學(xué)模型 .................. 24 IV 異步電機(jī)在 d,q,0 坐標(biāo)系統(tǒng)下的數(shù)學(xué)模型 ...................... 25 交流電機(jī)軟啟動(dòng)基本模塊仿真 ....................................... 26 交流電機(jī)軟啟動(dòng)系統(tǒng)仿真 ........................................... 30 5 交流電機(jī)軟啟動(dòng)系統(tǒng)仿真分析 ............................................ 31 SIMULINK 仿真分析 ................................................ 31 轉(zhuǎn)速 ...................................................... 31 轉(zhuǎn)矩 ...................................................... 31 定子電流 .................................................. 32 轉(zhuǎn)子電流 .................................................. 33 脈沖圖像 .................................................. 33 觸發(fā)角 alpha 的變化 ........................................ 34 電壓 ...................................................... 34 分析小結(jié) ........................................................ 35 6 總結(jié) .................................................................. 36 致 謝 ................................................................... 36 參 考 文 獻(xiàn) ............................................................. 38 交流電機(jī)軟啟動(dòng)的技術(shù)原理與仿真 1 1 交流軟啟動(dòng)概述 交流電機(jī)啟動(dòng)方式簡(jiǎn)介 交流電動(dòng)機(jī)廣泛應(yīng)用于各行各業(yè),但傳統(tǒng)電機(jī)的 直接 啟動(dòng)、停止制動(dòng)方式存在許多缺陷。然后分別對(duì)每種啟動(dòng)方式的優(yōu)缺點(diǎn)進(jìn)行了說(shuō)明,得出了 比較好的啟動(dòng)方式是電壓控制啟動(dòng)、轉(zhuǎn)矩控制啟動(dòng)和轉(zhuǎn)矩加突跳控制 啟動(dòng), 并且對(duì)變頻調(diào)速做了淺談使之與軟啟動(dòng)進(jìn)行比較得出了軟啟動(dòng)的優(yōu)缺點(diǎn)。 I 交流電機(jī)軟啟動(dòng)的技術(shù)原理與仿真 摘 要 本文首先闡述了交流電機(jī)的直接啟動(dòng),論述了直接啟動(dòng)的危害如電網(wǎng)沖擊,機(jī)械沖擊,對(duì)生產(chǎn)機(jī)械的沖擊等,敘述了交流電機(jī)直接啟動(dòng)的限制條件;并且將交流電機(jī)的直接啟動(dòng)和軟啟動(dòng)進(jìn)行比較,得出了軟啟動(dòng)對(duì)電網(wǎng)沖擊小,轉(zhuǎn)矩沖擊小且減少了對(duì)機(jī)器本身的損壞等優(yōu)點(diǎn)。 再次借助 Matlab/Simulink 工具箱和電氣系統(tǒng)模塊庫(kù) (Power System Blockset)對(duì)交流電機(jī)的軟啟動(dòng)過(guò)程進(jìn)行仿真研究,建立了三相交流電壓環(huán)節(jié)模塊、同步環(huán)節(jié)模塊、脈沖發(fā)生模塊、三相交流調(diào)壓模塊、電機(jī)及測(cè)量模塊、電流反饋、啟動(dòng)控制和電機(jī)切換等環(huán)節(jié)封裝模塊,構(gòu)建了完整的仿真系統(tǒng)模型,并分析了每個(gè)模塊的建立過(guò)程,參數(shù)設(shè)定及基本功能,給出了仿真結(jié)果,并對(duì)結(jié)果進(jìn)行了 分析和驗(yàn)證。啟動(dòng)時(shí)電流很大,啟動(dòng)電流可高達(dá)額定電流的 5~ 8 倍,這對(duì)電網(wǎng)、負(fù)載機(jī)械和電動(dòng)機(jī)造成巨大沖擊,影響電動(dòng)機(jī)和其拖動(dòng)設(shè)備的使用壽命,也造成電網(wǎng) 電壓突降,直接影響在電網(wǎng)用電的其它用電設(shè)備的正常工作。 交流電機(jī)直接啟動(dòng)的弊端及限制條件 直接啟動(dòng)是最簡(jiǎn)便的啟動(dòng)方式,啟動(dòng)時(shí)通過(guò)閘刀或接觸器將電機(jī)直 接接到電網(wǎng)上。 ( b) 對(duì)機(jī)械的沖擊:過(guò) 大的沖擊轉(zhuǎn)矩往往造成電機(jī)轉(zhuǎn)子籠條,端環(huán)斷裂和定子端部繞線絕緣磨損,導(dǎo)致?lián)舸龣C(jī);轉(zhuǎn)軸扭曲,聯(lián)軸節(jié),傳動(dòng)齒輪損傷和皮帶撕裂等。對(duì)于中、大功率的電動(dòng)機(jī)一般都不允許直接啟動(dòng),而要求采用一定的啟動(dòng)設(shè)備,方可完成正常的啟動(dòng)工作。下來(lái)介紹下這幾種 啟動(dòng)技術(shù)的優(yōu)缺點(diǎn)及適用范圍[3]: ( 1) Y— △降壓?jiǎn)?dòng)方式: Y-△降壓?jiǎn)?dòng)是將電動(dòng)機(jī)定子的三相繞組接成星型啟動(dòng),待電動(dòng)機(jī)速度達(dá)到額定轉(zhuǎn)速后,再換接成三角形轉(zhuǎn)入正常運(yùn)行。 ( 2)定子串電阻降壓?jiǎn)?dòng)方式: 在定子三相繞組串入電阻或電抗器,可在電動(dòng)機(jī)啟動(dòng)時(shí)分擔(dān)電壓,在電動(dòng)機(jī)速度到達(dá)額定轉(zhuǎn)速后,切除串接電阻或電抗器。 ( 3)轉(zhuǎn)子串電阻降壓?jiǎn)?dòng)方式: 轉(zhuǎn)子串電阻降壓?jiǎn)?dòng)只是用于轉(zhuǎn)子為繞組式的異步電機(jī)。 ( 4)自耦變壓器降壓?jiǎn)?dòng)方式: 自耦變壓器降壓?jiǎn)?dòng),是將自耦變壓器的原邊接入供電系統(tǒng),副邊 (即原邊繞組的一部分 )接到電動(dòng)機(jī)的定子繞組上。由于配電系統(tǒng)中的電流 (即自耦變壓