| 摘要 |
PURPOSE:To provide an electric automobile performing field-weakening control in order to operate an induction motor at high efficiency wherein instability due to variation of field current is prevented, torque control is performed stably, and magnetic noise due to variation of field current is suppressed. CONSTITUTION:A torque command tau* and a motor speed omegaM calculated at a vehicle drive operating section 15 are inputted to a weakening field operating section 20 in order to operate a flux command phi*. The torque command tau*is delayed through a torque delay element 21 to produce a reference torque tauR. A vector control operating section 22 performs vector control operation based on the reference torque tauR and the flux command phi* thus controlling the torque of an induction motor. Since flux current is increased prior to increase of output torqe by delaying the torque command tau* to establish a necessary flux, high efficiency is achieved through field current control with torque and stability can be ensured in the control system at the time of high torque output. |
