Improved trajectory control for an interior permanent magnet synchronous motor drive with extended operating limit

This paper presents analysis of trajectory control for an interior permanent magnet (IPM) synchronous motor drive under PWM current control. An improved trajectory control with extended speed range has been introduced. The scheme allows the motor to be driven with maximum-torque-per-ampere characteristic (MTPA) below the base speed and it maintains the maximum voltage limit of the motor under wide flux-weakening and the motor current limit under all conditions of operation accurately. Following the analysis of the trajectory control, the results of extensive simulation and experiment are given.