摘要:工業(yè)現(xiàn)場中,變頻器帶大慣性負載運行時,有時會遇到電網(wǎng)瞬時停電的情況,由于負載慣性大,電網(wǎng)瞬時停電再來電后,電機不能立即起動運行。針對這種情況,提出了一種新的解決方法:瞬時停電后,變頻器有規(guī)律地降頻運行,使異步電動機進入微發(fā)電狀態(tài),電機與變頻器構(gòu)成一個自治系統(tǒng),以維持變頻器母線電壓。來電后,變頻器從當(dāng)前運行頻率處,再恢復(fù)到額定運行狀態(tài)。對所提出的方案,在山東新風(fēng)光電子科技發(fā)展有限公司生產(chǎn)的JD—BP32變頻器上進行了試驗,試驗結(jié)果驗證了控制方案的正確性。
關(guān)鍵詞:感應(yīng)發(fā)電機 變頻器 母線電壓 大慣性負載 瞬時停電
[b][align=center]Novel M ethod of M aintaining D.C.Link Voltage of
Inverter in Power Interruption
Kong Weitao Zhang Qingfan LiRuilai He Hongchen
(1.Shandong University Jinan 25006 1 China
2.Shandong Xinfengguang Electronic Science and Technology
Development Ltd. Wenshang 272500 China)[/align][/b]
Abstract:Power interruption sometimes occurs in 1ndustrial process where 1nverters are operating with large inertial load.Due to the large inertial load,the induction motor cannot be restarted up when power supply comes back.This article proposes a new method to solve this problem .In the process of power interruption the inverter reduces the operate frequency regularly to make th einduction motor enter into the slightly generating mode and then the induction motor and the inverter make up of an autonomous system to maintain the d.C.1ink voltage of the inverter.W hen power supply comes back,the inverter recovers to rated operate state from the current operate frequency.The proposed m ethod is tested with JD—BP32 inverter made by Shandong Xin Fengguan g Electronic Science and Technology Developm ent Ltd.a(chǎn)nd the corection of the control strategy is verified.
Keywords:Induction generator,inverter,d.C.1ink voltage,large inertial load,power interruption
1 引言
工業(yè)現(xiàn)場中,風(fēng)機、泵類等負載占有相當(dāng)大的比重,這類負載中有些屬于大慣性負載。電機帶大慣性負載運行時,如果電網(wǎng)電壓因為某種原因(如自動重合閘裝置動作等)暫時中斷,電網(wǎng)瞬時停電再來電,電機由于負載慣性大不能停轉(zhuǎn),變頻器一般不能立即重新起動電機,而是等電機完全停轉(zhuǎn)之后,再重新起動電機:否則,在電機減速過程中,變頻器輸出電壓頻率與電機轉(zhuǎn)速所對應(yīng)頻率如果相差很大,易造成電機繞組過電流,損壞電機。這樣,電機就存在一個長時間的停車過程,影響正常的工業(yè)生產(chǎn)。
[b][align=center]詳細內(nèi)容請點擊:
電網(wǎng)瞬時停電保持變頻器母線電壓的新方法[/align][/b]