一、什么是風電變流器
風(feng)電變流(liu)器(qi),是(shi)雙饋風(feng)力發電機中,加在轉子側的勵(li)磁裝置,其主(zhu)要功能是(shi)在轉子轉速(su)n變化時,通過變流(liu)器(qi)控(kong)制勵(li)磁的幅(fu)值、相位、頻率等,使定子側能向電網輸(shu)入恒頻電。
二、風電變流器的結構組成
風(feng)(feng)電(dian)(dian)變流器可以優(you)化風(feng)(feng)力發電(dian)(dian)系統的(de)運行,實現寬風(feng)(feng)速范圍內的(de)變速恒頻發電(dian)(dian),改善風(feng)(feng)機效率(lv)(lv)和傳輸鏈的(de)工作狀況,減少發電(dian)(dian)機損耗,提高運行效率(lv)(lv),提升風(feng)(feng)能利用率(lv)(lv),在(zai)風(feng)(feng)電(dian)(dian)領域應用廣(guang)泛,那么(me)風(feng)(feng)電(dian)(dian)變流器的(de)結(jie)構由哪些(xie)部分組(zu)成(cheng)呢?
風(feng)電變(bian)流器(qi)由主電路系(xi)統、配(pei)電系(xi)統以及控制系(xi)統構成(cheng),其零部件主要(yao)有(you)定子并網(wang)開關、整流模(mo)塊、逆變(bian)模(mo)塊、輸入(ru)/輸出(chu)濾波器(qi)、IGBT、PLC、JCE1000-AXS電流傳感器(qi)、風(feng)機、有(you)源(yuan)Crowbar電路、控制器(qi)、監控界面等。
1、變(bian)流器(qi)主(zhu)電路系統包(bao)括轉子側逆變(bian)器(qi)、直(zhi)流母線單元、電網側整流器(qi)。
2、配電系統(tong)由并網接觸器(qi)、主(zhu)斷路器(qi)、繼電器(qi)、變(bian)壓器(qi)等組成,自身集(ji)成有并網控制系統(tong)。
3、控(kong)(kong)制系統由(you)高(gao)速數字信號處理器(DSP)、人(ren)機操作界面和可編(bian)程邏輯(ji)控(kong)(kong)制器(PLC)共同構(gou)成(cheng)。
三、風電變流器工作原理是什么
風電(dian)變流器(qi)采用三相電(dian)壓型交-直-交雙向變流器(qi)技術,通過(guo)對雙饋異(yi)步風力發電(dian)機的(de)轉子(zi)進行勵磁,使得雙饋發電(dian)機的(de)定子(zi)側輸出電(dian)壓的(de)幅值、頻率(lv)和相位與(yu)電(dian)網(wang)相同,并且(qie)可根據需要進行有功和無功的(de)獨(du)立解耦(ou)控制,具(ju)體的(de)工作原(yuan)理是(shi):
在直(zhi)(zhi)驅型風力發電(dian)(dian)系統中(zhong),全功率(lv)變(bian)(bian)(bian)(bian)流(liu)器是(shi)永磁同步發電(dian)(dian)機與電(dian)(dian)網之(zhi)間(jian)的(de)橋梁。永磁同步發電(dian)(dian)機發出的(de)交流(liu)電(dian)(dian)是(shi)隨(sui)著風的(de)變(bian)(bian)(bian)(bian)化(hua)而(er)變(bian)(bian)(bian)(bian)化(hua)的(de),不能直(zhi)(zhi)接(jie)接(jie)入電(dian)(dian)網。變(bian)(bian)(bian)(bian)流(liu)器的(de)機側對(dui)幅值和頻率(lv)變(bian)(bian)(bian)(bian)化(hua)的(de)交流(liu)進行PWM整流(liu),整流(liu)后的(de)直(zhi)(zhi)流(liu)經變(bian)(bian)(bian)(bian)流(liu)器的(de)網側進行PWM逆變(bian)(bian)(bian)(bian),將直(zhi)(zhi)流(liu)逆變(bian)(bian)(bian)(bian)成(cheng)幅值和頻率(lv)穩(wen)定的(de)交流(liu),經濾波器、升壓(ya)變(bian)(bian)(bian)(bian)壓(ya)器并入電(dian)(dian)網。
風電變流器的(de)機(ji)(ji)(ji)(ji)側(ce)(ce)接入永磁發電(dian)機(ji)(ji)(ji)(ji)的(de)兩個(ge)繞(rao)組(zu)(zu),根據(ju)主控(kong)系統(tong)轉矩指令,機(ji)(ji)(ji)(ji)側(ce)(ce)1#繞(rao)組(zu)(zu)控(kong)制(zhi)(zhi)(zhi)系統(tong)控(kong)制(zhi)(zhi)(zhi)1#橋(qiao)單(dan)元,機(ji)(ji)(ji)(ji)側(ce)(ce)2#繞(rao)組(zu)(zu)控(kong)制(zhi)(zhi)(zhi)系統(tong)控(kong)制(zhi)(zhi)(zhi)2#橋(qiao)單(dan)元,進(jin)(jin)行PWM整流(liu)(liu),從而(er)實現變(bian)(bian)流(liu)(liu)器(qi)對(dui)永磁同步發電(dian)機(ji)(ji)(ji)(ji)的(de)控(kong)制(zhi)(zhi)(zhi)。變(bian)(bian)流(liu)(liu)器(qi)的(de)網(wang)(wang)側(ce)(ce)輸出接到(dao)升壓(ya)變(bian)(bian)壓(ya)器(qi)并(bing)網(wang)(wang),根據(ju)直流(liu)(liu)電(dian)壓(ya)和主控(kong)下設無(wu)(wu)功(gong)(gong)(gong)功(gong)(gong)(gong)率,網(wang)(wang)側(ce)(ce)控(kong)制(zhi)(zhi)(zhi)系統(tong)采(cai)用矢量控(kong)制(zhi)(zhi)(zhi)技術控(kong)制(zhi)(zhi)(zhi)三個(ge)相單(dan)元,將有功(gong)(gong)(gong)和設定的(de)無(wu)(wu)功(gong)(gong)(gong)經濾波器(qi)送入電(dian)網(wang)(wang)。如果單(dan)獨(du)運行網(wang)(wang)側(ce)(ce)逆變(bian)(bian)單(dan)元,可以作為靜態無(wu)(wu)功(gong)(gong)(gong)發生(sheng)器(qi)(SVG)使用,對(dui)電(dian)網(wang)(wang)進(jin)(jin)行無(wu)(wu)功(gong)(gong)(gong)補償。控(kong)制(zhi)(zhi)(zhi)系統(tong)采(cai)用三個(ge)DSP分別對(dui)變(bian)(bian)流(liu)(liu)器(qi)的(de)電(dian)機(ji)(ji)(ji)(ji)側(ce)(ce)1#繞(rao)組(zu)(zu)、電(dian)機(ji)(ji)(ji)(ji)側(ce)(ce)2#繞(rao)組(zu)(zu)和電(dian)網(wang)(wang)側(ce)(ce)進(jin)(jin)行控(kong)制(zhi)(zhi)(zhi),在三個(ge)DSP之(zhi)(zhi)間(jian)采(cai)用高速串行總線進(jin)(jin)行通訊以協調機(ji)(ji)(ji)(ji)側(ce)(ce)和網(wang)(wang)側(ce)(ce)之(zhi)(zhi)間(jian)的(de)工作。