Operation along the maximum torque per voltage trajectory in a direct torque and flux controlled interior permanent magnet synchronous motor

The direct torque and flux control (DTFC) scheme is well known for its simplicity and less parameter dependency compared to the conventional current vector control scheme. It can drive an interior permanent magnet synchronous motor (IPMSM) in usual control regimes while satisfying current and voltage limits of the motor and inverter. If the characteristic current of an IPMSM is less than the rated current of the system, maximum torque per voltage (MTPV) control can be carried out in the flux weakening operation to increase the motor speed further. Though MTPV control is well established in the current vector control scheme it has not been instigated as extensively, specially operation along the MTPV trajectory in the torque-flux plane using DTFC scheme. This paper attempts to fill that gap by proposing a simple and effective control method for the MTPV operation of a direct torque and flux controlled IPMSM. The simulation and experimental results support the analysis.