三相摩打起動問題

三相摩打起動用火牛起動接法既作用係現將電壓用火牛降低來作爲三相摩打起動以減少起動電流, 好處係可以用在比較大既三相摩打, 尤其係高電壓 (3300V ~ 33000V) 三相摩打, 因爲如果要用星角起動就要6條電線, 火牛起動就用3條電線。


圖片參考：http://img.en.china.cn/0/0,0,407,3408,411,445,b0ed8c0b.jpg



圖片參考：http://victoruae.com/images/images//motorstarting_diag1.gif




圖片參考：http://www.claytonengineering.com/training/myweb6/module21/output/images/RVSFIG66.jpg



圖片參考：http://www.stabilizer-transformer.com/upfiles/1246584684three%20phase%20autotransformer.jpg


圖片參考：http://www.transmag-transformers.co.uk/img/Korndorffer_Transformer.jpg

Both star-delta and auto-transformer starters are the same!
They reduce the starting voltage of the motor and reduce the starting current.
Modern design motor starters replaced those old technology with either "soft- starter " or VSD (Variable Speed drive). Generally limit the motor starting current below 1.5 of the motor duty current.