基于電網(wǎng)電壓補(bǔ)償?shù)亩嚯娖阶冾l器控制
時(shí)間:2008-04-25 09:54:00來(lái)源:yangliu
導(dǎo)語(yǔ):?詳細(xì)介紹了適合于多電平變頻器控制的理論分析和算法推導(dǎo)過(guò)程,提出 一種基于電列電壓補(bǔ)償?shù)亩嚯娖阶冾l器控制方法,并給出了適合數(shù)字信號(hào)處理的采樣原理和采樣時(shí)序
摘 要:為了改善電網(wǎng)電壓補(bǔ)償效果,從主吲路拓?fù)浣Y(jié)構(gòu)出發(fā),以低壓變頻器規(guī)則采樣法為基本理論,詳細(xì)介紹了適合于多電平變頻器控制的理論分析和算法推導(dǎo)過(guò)程,提出一種基于電列電壓補(bǔ)償?shù)亩嚯娖阶冾l器控制方法,并給出了適合數(shù)字信號(hào)處理的采樣原理和采樣時(shí)序。根據(jù)電網(wǎng)電壓的變化,實(shí)時(shí)調(diào)節(jié)輸出電壓,獲得與閉環(huán)系統(tǒng)相同的理想機(jī)械特性和運(yùn)行效果 該方法具有計(jì)算步驟簡(jiǎn)單、輸出sPwM對(duì)稱性好、精度高和控制方便的特點(diǎn),適用于任何電平數(shù)目及拓?fù)浣Y(jié)構(gòu)。試驗(yàn)結(jié)果表明,和其他多電平控制方法相比,使用效果好,有很高的利用價(jià)值。
關(guān)鍵詞:電網(wǎng)電壓補(bǔ)償;多電平變頻器;采樣;SPWM
[b][align=center]Control method for multilevel converters based on power
compensation of network voltage
PAN Ai.xian ,W EI Li2
. ZHANG M in
(1.College of Automation,Qingdao Technological University Qingdao,266033;2.Xi‘An University of Science
and Technology,Xi‘An 710054,China)[/align][/b]
Abstract:In order to improve the compensation effect of power network voltage, a new method for multilevel converters based on the compensation of power network voltagO is proposed.The article begin with the structure of
main-loop and takes the regular sample theorem of low-voltage converter as the basic theory.Then it introduces the theory analyzing and algorithm deducing process in detail which is propitious to multilevel converter contro1.
Sample theorem and sample time which are applied in digital process are also proposed.In order to acquire ideal mechanical character and running performance as closed loop,it regulates output voltage at times according to the variety of the voltage of power network.The method not only has great advantages such as simple calculation,high preponderan ce in the symmetry of SPW M output wave,high precision and convenience in control,but also it is
applicable for any number of levels and structure.The results show that it has practical value for multilevel converter compared with other methods.
Key words: compensation of power network voltage: multilevel converter: sam ple: SPWM
0 引 言
近年來(lái),多電平變頻器在高電壓、大功率變頻裝置中得到了越來(lái)越廣泛的應(yīng)用,其基本拓?fù)浣Y(jié)構(gòu)為二極管嵌位、飛跨電容、多電平串聯(lián)3種形式,相比較而言,多電平串聯(lián)型具有如下優(yōu)點(diǎn):
(1)采用功率單元串聯(lián),而非功率器件串聯(lián)方案,電路中省去了大量的嵌位二極管和電壓平衡電容器;各功率單元采用模塊化結(jié)構(gòu),可互換,維修方便。
(2)逆變器結(jié)構(gòu)基于傳統(tǒng)的兩電平逆變器單元形式,主回路拓?fù)浣Y(jié)構(gòu)非常簡(jiǎn)單。
(3)每一個(gè)逆變橋由相互獨(dú)立的直流電壓源供電,不存在中性點(diǎn)電壓不平衡的問(wèn)題。
這類變頻器多采用開(kāi)環(huán)控制方案,電網(wǎng)電壓的波動(dòng),商接影響輸出電壓,繼而影響電機(jī)的輸出功率。如果能夠在不影響系統(tǒng)結(jié)構(gòu)的情況下,直接根據(jù)電網(wǎng)電壓的變化,實(shí)時(shí)調(diào)節(jié)輸出電壓,將會(huì)直接獲得與閉環(huán)系統(tǒng)相似的理想機(jī)械特性和運(yùn)行效果。
[b]1 多單元串聯(lián)大功率逆變?cè)?
1.1 主回路拓?fù)浣Y(jié)構(gòu)[/b]
[b][align=center]詳細(xì)內(nèi)容請(qǐng)點(diǎn)擊:
基于電網(wǎng)電壓補(bǔ)償?shù)亩嚯娖阶冾l器控制[/align][/b]