The mechanical frequency is measurable but the slip must be estimated as explained in the RRF orientation section.If you’ve browsed the aisles in your local building-supply store recently, you’ve no doubt noticed some big changes in the power-tool and garden-appliance sections. In an induction machine, the rotor flux frequency is the sum of the mechanical frequency and the slip frequency. In this note, Rotor Field-Oriented Control (RFOC) is chosen for its simplicity and higher torque dynamics . Decoupled control of torque and flux quantities can be achieved by orienting the RRF on the stator flux, rotor flux or air-gap flux. Therefore, unlike a PMSM ( TN111), there are multiple ways to orient the RRF for an IM. Choice of the orientationĪs mentioned above, the rotor is not necessarily rotating at the same speed as the stator (mechanically speaking). Consequently, the FOC from the PMSM must be adapted to take these key differences into account. What’s more, the IM does not have permanent magnets on the rotor: instead, the rotor is magnetized from the stator. However, there are two key differences between a PMSM and an IM : the rotor of the IM is mechanically not synchronous with the stator flux. In the case of an induction machine with a squirrel cage, the general idea is the same: the flux and torque are controlled independently in a Reference Rotating Frame (RRF) by – respectively – the d and q components of the stator current. The technical note TN111 introduces the principles of a Field-Oriented Control (FOC) for a Permanent Magnets Synchronous Machine (PMSM). General principles of Rotor Field-Oriented Control TN139_Extended_for_Motor_Testbench additionally includes a torque-controlled PMSM, similarly to the motor testbench used in the Experimental results section.TN139_Rotor_Field_Oriented_Ctrl_of_IM, deals with the RFOC control of a single induction machine, damped by an external torque source.TN139_Extended_for_Motor_Testbench Download Please note that imperix offers a ready-to-use motor drive system to develop and test motor control techniques. Then, it explains how the stator’s electrical speed and position can be estimated from the mechanical speed of the rotor.įinally, a practical control implementation is introduced, targeting the B-Box RCP or B-Board PRO with the ACG SDK on Simulink. This technical note presents a possible implementation of a Rotor Field-Oriented Control (RFOC) of an Induction Machine (IM) with a squirrel cage.įirst, the note introduces the general operating principles of the RFOC.

Comparison between Rotor Field-Oriented Control and V/f control.

Experimental results of Rotor Field-Oriented Control.

B-Box / B-Board implementation of Rotor Field-Oriented Control.

General principles of Rotor Field-Oriented Control.

Field oriented control