As far as I know all variable frequency drives with vector control can also be run with just V\/F control.<\/p>\n
A drive in vector control mode has several tuning parameters to increase or decrease motor performance. With factory default parameters a VFD in vector mode will have higher performance than a drive in V\/F mode. Sort of like a “sport or racing” computer option in a modern automobile.<\/p>\n
Depending on the application using vector control can use a lot more power. If you have a rapidly surging load the vector may be really struggling to keep the speed constant while a variable frequency drive in V\/F mode never notices the speed change. If the application has a steady mid-range speed and load or has a slow rate of change a vector and V\/F may be very close in amp draw.<\/p>\n
If you have an application where you need the vector for starting or stopping quickly but you are using a lot of current at speed you can change vector parameters to reduce the current. In some applications it is cheaper to oversize a V\/F drive to get starting or stopping torque if you don’t need precise speed control.
\nI accept the fact that, in the practice, V\/f is considered by many the better choice for fan loads, but I see few reasons why V\/f approach could result in better efficiency.<\/p>\n
One reason could be that, since it doesn’t try to regulate anything, practically it can’t oscillate due to weak stability, although oscillations may still occur (I’ve seen a heavily vibrating torque measurement on a fan driven by a V\/f variable frequency drive).
\nAnother could be that, while non-linear V\/f curves (suitable to non-linear loads as fans) are quite common, the same is not done for the flux reference (magnitude) in vector control.
\nAnd, of course, the few parameters of a V\/f control are far easier to tune than a vector scheme (which companies don’t really share).<\/p>\n
However, one interesting thing that can be done with vector control is, for slow dynamics applications, to automatically tune the flux reference to achieve a minimum loss control during the control operation. I don’t think this would be possible with V\/f.<\/p>\n","protected":false},"excerpt":{"rendered":"
As far as I know all variable frequency drives with vector control can also be run with just V\/F control.<\/p>\n
A drive in vector control mode has several tuning parameters to increase or decrease motor performance. With factory default parameters a VFD in vector mode will have higher performance than a drive in V\/F mode. Sort of like a “sport or racing” computer option in a modern automobile.<\/p>\n
Depending on the application using vector control can use a lot more power. If you have a rapidly surging load the vector may be really struggling to keep the speed constant while a variable frequency drive in V\/F mode never notices the speed change. If the application has a steady mid-range speed and load or has a slow rate of change a vector and V\/F may be very close in amp draw.<\/p>\n
If you have an application where you need the vector for starting or stopping quickly but you are using a lot of current at speed you can change vector parameters to reduce the current. In some applications it is cheaper to oversize a V\/F drive to get starting or stopping torque if you don’t need precise speed control.
\nI accept the fact that, in the practice, V\/f is considered by many the better choice for fan loads, but I see few reasons why V\/f approach could result in better efficiency.<\/p>\n
One reason could be that, since it doesn’t try to regulate anything, practically it can’t oscillate due to weak stability, although oscillations may still occur (I’ve seen a heavily vibrating torque measurement on a fan driven by a V\/f variable frequency drive).
\nAnother could be that, while non-linear V\/f curves (suitable to non-linear loads as fans) are quite common, the same is not done for the flux reference (magnitude) in vector control.
\nAnd, of course, the few parameters of a V\/f control are far easier to tune than a vector scheme (which companies don’t really share).<\/p>\n
However, one interesting thing that can be done with vector control is, for slow dynamics applications, to automatically tune the flux reference to achieve a minimum loss control during the control operation. I don’t think this would be possible with V\/f.<\/p>\n","protected":false},"author":0,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[67],"tags":[],"class_list":["post-14188","post","type-post","status-publish","format-standard","hentry","category-iacdrive_blog"],"_links":{"self":[{"href":"http:\/\/iacdrive.com\/index.php?rest_route=\/wp\/v2\/posts\/14188","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/iacdrive.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/iacdrive.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"replies":[{"embeddable":true,"href":"http:\/\/iacdrive.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=14188"}],"version-history":[{"count":0,"href":"http:\/\/iacdrive.com\/index.php?rest_route=\/wp\/v2\/posts\/14188\/revisions"}],"wp:attachment":[{"href":"http:\/\/iacdrive.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=14188"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/iacdrive.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=14188"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/iacdrive.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=14188"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}