Editing Synchronous motor (section)

== Control techniques ==
A permanent magnet synchronous motor and reluctance motor requires a control system for operating ([[Variable-frequency drive|VFD]] or [[servo drive]]).

There is a large number of control methods for synchronous machines, selected depending on the construction of the electric motor and the scope.

Control methods can be divided into:{{sfn | Finch | Giaouris | 2008 | pp=483–484}}{{sfn | Buja | Kazmierkowski | 2004 | p=745}}
* [[Scalar control]]
** [[V/f control]]
* [[Vector control (motor)|Vector control]]
** [[Field oriented control]]
** [[Direct torque control]], a variant of VC
** [[Feedback linearization]]
** [[Passivity based control]]

The PMSMs can also operate on open-loop control,{{sfn | Finch | Giaouris | 2008 | p=482}} which is sometimes used for start-up thus enabling the position sensing operation.{{sfn | Acarnley | Watson | 2006 | p=353}}