Abstract:
A method of controlling torque of a permanent magnet synchronous motor (PMSM) by using a speed-torque lookup table may include: receiving a current direct-current (DC) link voltage of an inverter configured to drive the PMSM and a speed of a rotor of the PMSM; calculating a change ratio of a DC link voltage based on the current DC link voltage and a DC link voltage at a time when the speed-torque lookup table is generated; calculating a normalized speed of the rotor according to a change in the DC link voltage by using the speed of the rotor and the change ratio of the DC link voltage; and/or transferring the normalized speed of the rotor as an input to the speed-torque lookup table.
Abstract:
A method of compensating for a friction torque of a permanent magnet synchronous motor may include: receiving input of a motor current and a rotor speed of the permanent magnet synchronous motor; estimating a motor torque based on the input motor current; acquiring a first friction torque corresponding to the input rotor speed and the estimated motor torque by using a lookup table of friction torques; compensating for a second friction torque of the permanent magnet synchronous motor based on the first friction torque, wherein the compensating is in response to a first torque command input to control driving of the permanent magnet synchronous motor and outputs a second torque command that compensates for the second friction torque; and/or controlling the driving of the permanent magnet synchronous motor based on the second torque command.