變頻器是運動控製係統中的功率變換器。當今的運動控製係統包含多種學科的技術領域,總的發展趨勢是:驅動的交流化,功率變換器的高頻化,控製的數字化、智能化和網絡化。因此,變頻器作為係統的重要功率變換部件,提供可控的高性能變壓變頻的交流電源而得到迅猛發展。
suizhexinxingdianlidianziqijianhegaoxingnengweichuliqideyingyongyijikongzhijishudefazhan,bianpinqidexingnengjiagebiyuelaiyuegao,tijiyuelaiyuexiao,erchangjiarengranzaibuduanditigaokekaoxingshixianbianpinqidejinyibuxiaoxingqinglianghua、高性能化和多功能化以及無公害化而做著新的努力。變頻器性能的優劣,一要看其輸出交流電壓的諧波對電機的影響;二要看對電網的諧波汙染和輸入功率因數;三要看本身的能量損耗(即效率)如何。這裏僅以量大麵廣的交—直—交變頻器為例,闡述它的發展趨勢:
主電路功率開關元件的自關斷化、模塊化、集成化、智能化;開關頻率不斷提高,開關損耗進一步降低。
變頻器主電路的拓撲結構方麵。變頻器的網側變流器對低壓小容量的裝置常采用6脈衝變流器,而對中壓大容量的裝置采用多重化12脈mai衝chong以yi上shang的de變bian流liu器qi。負fu載zai側ce變bian流liu器qi對dui低di壓ya小xiao容rong量liang裝zhuang置zhi常chang采cai用yong兩liang電dian平ping的de橋qiao式shi逆ni變bian器qi,而er對dui中zhong壓ya大da容rong量liang的de裝zhuang置zhi采cai用yong多duo電dian平ping逆ni變bian器qi。對dui於yu四si象xiang限xian運yun行xing的de轉zhuan動dong,為wei實shi現xian變bian頻pin器qi再zai生sheng能neng量liang向xiang電dian網wang回hui饋kui和he節jie省sheng能neng量liang,網wang側ce變bian流liu器qi應ying為wei可ke逆ni變bian流liu器qi,同tong時shi出chu現xian了le功gong率lv可ke雙shuang向xiang流liu動dong的de雙shuangPWM變頻器,對網側變流器加以適當控製可使輸入電流接近正弦波,減少對電網的公害。
脈寬調製變壓變頻器的控製方法可以采用正弦波脈寬調製控製、消除指定次數諧波的PWM控製、電流跟蹤控製、電壓空間矢量控製(磁鏈跟蹤控製)。
jiaoliudiandongjibianpintiaozhengkongzhifangfadejinzhanzhuyaotixianzaiyoubiaoliangkongzhixianggaodongtaixingnengdeshiliangkongzhiyuzhijiezhuanjukongzhifazhanhekaifawusuduchuanganqideshiliangkongzhihezhijiezhuanjukongzhixitongfangmian。
微wei處chu理li器qi的de進jin步bu使shi數shu字zi控kong製zhi成cheng為wei現xian代dai控kong製zhi器qi的de發fa展zhan方fang向xiang。運yun動dong控kong製zhi係xi統tong是shi快kuai速su係xi統tong,特te別bie是shi交jiao流liu電dian動dong機ji高gao性xing能neng的de控kong製zhi需xu要yao存cun儲chu多duo種zhong數shu據ju和he快kuai速su實shi時shi處chu理li大da量liang信xin息xi。近jin幾ji年nian來lai,國guo外wai各ge大da公gong司si紛fen紛fen推tui出chu以yiDSP(數字信號處理器)為基礎的內核,配以電機控製所需的外圍功能電路,集成在單一芯片內的稱為DSP單片電機控製器,價格大大降低,體積縮小,結構緊湊,使用便捷,可靠性提高。DSP和普通的單片機相比,處理數字運算能力增強10~15bei,kequebaoxitongyougengyouyuedekongzhixingneng。shuzikongzhishiyingjianjianhua,rouxingdekongzhisuanfashikongzhijuyouhendadelinghuoxing,keshixianfuzakongzhiguilv,shixiandaikongzhililunzaiyundongkongzhixitongzhongyingyongchengweixianshi,yiyuyushangcengxitonglianjiejinxingshujuchuanshu,bianyuguzhangzhenduan、加強保護和監視功能,使係統智能化(如有些變頻器具有自調整功能)。
jiaoliutongbudiandongjiyichengweijiaoliuketiaozhuandongzhongdeyikexinxing,tebieshiyongcitongbudiandongji,dianjihuodewushuajiegou,gonglvyinshugao,xiaolvyegao,zhuanzizhuansuyangeyudianyuanpinlvbaochitongbu。tongbudianjibianpintiaosuxitongyoutakongbianpinhezikongbianpinliangdalei,zikongbianpintongbudianjizaiyuanlishanghezhiliudianjijiweixiangsi,yongdianlidianzibianliuqiqudailezhiliudianjidejixiehuanxiangqi,rucaiyongjiao—直—交變壓變頻器時叫做“直流無換向器電機”或稱“無刷直流電動機”。傳(chuan)統(tong)的(de)自(zi)控(kong)變(bian)頻(pin)同(tong)步(bu)機(ji)調(tiao)速(su)係(xi)統(tong)有(you)轉(zhuan)子(zi)位(wei)置(zhi)傳(chuan)感(gan)器(qi),現(xian)正(zheng)開(kai)發(fa)無(wu)轉(zhuan)子(zi)位(wei)置(zhi)傳(chuan)感(gan)器(qi)的(de)係(xi)統(tong)。同(tong)步(bu)電(dian)機(ji)的(de)他(ta)控(kong)變(bian)頻(pin)方(fang)式(shi)也(ye)可(ke)采(cai)用(yong)矢(shi)量(liang)控(kong)製(zhi),其(qi)按(an)轉(zhuan)子(zi)磁(ci)場(chang)定(ding)向(xiang)的(de)矢(shi)量(liang)控(kong)製(zhi)比(bi)異(yi)步(bu)電(dian)機(ji)簡(jian)單(dan)。