Flux weakening control for surface mount permanent magnet synchronous motor (PMSM) drives with rapid load and speed varying applications

An adaptive flux weakening control scheme is proposed for the surface permanent magnet synchronous machine (PMSM). The method adaptively controls the demagnetizing current with changes in speed or load torque. The method does not require DC bus voltage sensing of the power converter and unsusceptible to the motor parameter changes. No requirement of bus voltage makes it suitable for voltage sensor less control in battery operated hybrid electric drives where supply voltage changes with state of charge (SoC) of the battery pack. The control scheme is mostly suitable for variable speed operation where rapid speed changes occur. Response time is made faster by incorporating necessary alteration in previous methods. Faster response time on controlling the demagnetizing currents ensures more energy efficient operation. Simulation and experimental results are presented to demonstrate the functionality of the proposed scheme.