Abstract: Disclosed is a flux controller for maintaining reliable flux estimation performance in a low velocity region, the controller including a velocity controller, a torque current controller for outputting a torque voltage command, a flux controller for outputting a flux current command, a flux current controller for receiving the flux current command to output a flux voltage command, a three-phase converter for converting the torque voltage command and the flux voltage command into a three-phase voltage command applied to the induction motor to output the three-phase voltage command, a flux estimator for outputting a rotating angle of a rotor of the induction motor, an estimated flux value of the rotor and an estimated velocity of the rotor, and a flux regulator for receiving the torque voltage command and the estimated velocity to output a gain value that regulates a magnitude of the flux command.

Abstract: An inverter for an electric vehicle includes a speed instruction generating unit, a frequency voltage converting unit, an integrator and a 2-to-3 phase converter. The speed instruction generating unit outputs a speed instruction for changing the rotational frequency of an electric motor based on the on/off of a signal outputted from the accelerator pedal. The frequency voltage converting unit outputs a voltage instruction based on the frequency of the speed instruction. The integrator outputs a rotational angle by performing integration on the frequency of the speed instruction. The 2-to-3 phase converter receives the voltage instruction and the rotational angle and converts the received voltage instruction and rotational angle into three-phase voltage instructions.

Abstract: Disclosed is a flux controller for maintaining reliable flux estimation performance in a low velocity region, the controller including a velocity controller, a torque current controller for outputting a torque voltage command, a flux controller for outputting a flux current command, a flux current controller for receiving the flux current command to output a flux voltage command, a three-phase converter for converting the torque voltage command and the flux voltage command into a three-phase voltage command applied to the induction motor to output the three-phase voltage command, a flux estimator for outputting a rotating angle of a rotor of the induction motor, an estimated flux value of the rotor and an estimated velocity of the rotor, and a flux regulator for receiving the torque voltage command and the estimated velocity to output a gain value that regulates a magnitude of the flux command.

Abstract: An inverter for an electric vehicle includes a speed instruction generating unit, a frequency voltage converting unit, an integrator and a 2-to-3 phase converter. The speed instruction generating unit outputs a speed instruction for changing the rotational frequency of an electric motor based on the on/off of a signal outputted from the accelerator pedal. The frequency voltage converting unit outputs a voltage instruction based on the frequency of the speed instruction. The integrator outputs a rotational angle by performing integration on the frequency of the speed instruction. The 2-to-3 phase converter receives the voltage instruction and the rotational angle and converts the received voltage instruction and rotational angle into three-phase voltage instructions.

Abstract: A speed control apparatus for operating a cage of an elevator at a speed suitable for a required operation condition is capable of reducing a mechanical vibration generated from the cage by obtaining a torque of the winding machine from a speed-controlled current command and an acceleration of the winding machine from the torque and the present acceleration of the winding machine to compensate for and output the value of the current command when a high speed elevator having a low mechanical resonant frequency is operated.