Abstract: An inverter control method for controlling a switching of an inverter in a vehicle, the vehicle having: a motor for transmitting torque to drive wheels; the inverter for converting DC power into AC power mutually and supplying the AC power to the motor; and a DC power source for supplying the DC power to the inverter, the control method including: determining whether or not a power supply to the inverter is stopped; executing a short-circuit switching control to turn on switching elements provided in the inverter when the power supply to the inverter is stopped; obtaining a motor state parameter as a variable representing a state of the motor, the motor state parameter being used as a determination standard for determining whether or not an oscillation occurs in the vehicle; and stopping the short-circuit switching control before the oscillation occurs in the vehicle based on the motor state parameter obtained, when the power supply to the inverter is stopped.

Abstract: A motor control device for controlling an electric motor (1,6) installed in a vehicle, is disclosed. The motor has a field winding (101,601). The motor control device has a battery (4) charged by power at a first voltage (Vb), an voltage increase/decrease inverter (3) capable of increasing the first voltage from the battery, an excitation control circuit (102, 106) which allows or disallows supply of the exciting current to the field winding (101,601), a sensor (35,41–48) which detects a state of the vehicle, and a controller (8). The controller (8) determines whether or not to start the motor (1,6) based on a signal from the sensor (41–48). When the motor is to be started, the controller (8) allows supply of exciting current by the excitation control circuit (102, 106) and controls the voltage increasing circuit so that the first voltage is increased to a second voltage higher than the first voltage (Vb).

Abstract: A motor control device for controlling an electric motor (1,6) installed in a vehicle, is disclosed. The motor has a field winding (101,601). The motor control device has a battery (4) charged by power at a first voltage (Vb), an voltage increase/decrease inverter (3) capable of increasing the first voltage from the battery, an excitation control circuit (102, 106) which allows or disallows supply of the exciting current to the field winding (101,601), a sensor (35,41-48) which detects a state of the vehicle, and a controller (8). The controller (8) determines whether or not to start the motor (1,6) based on a signal from the sensor (41-48). When the motor is to be started, the controller (8) allows supply of exciting current by the excitation control circuit (102, 106) and controls the voltage increasing circuit so that the first voltage is increased to a second voltage higher than the first voltage (Vb).

Abstract: In an inverter which implements drive control on a three-phase AC motor by detecting a first-phase current value and a second-phase current value among three-phase alternating current values with two current sensors, one of the current sensors is determined to be abnormal if one of the absolute value of the deviation of the first-phase current detection value relative to a first current command value and the absolute value of the deviation of the second-phase current detection value relative to a second-phase current command value exceeds a first judgement reference value while the three-phase AC motor is being driven.

Abstract: In an inverter which implements drive control on a three-phase AC motor by detecting a first-phase current value and a second-phase current value among three-phase alternating current values with two current sensors, one of the current sensors is determined to be abnormal if one of the absolute value of the deviation of the first-phase current detection value relative to a first current command value and the absolute value of the deviation of the second-phase current detection value relative to a second-phase current command value exceeds a first judgement reference value while the three-phase AC motor is being driven.

Abstract: An apparatus for a pole change induction motor and control method for the same which are applicable to, for example, a driving source of an electric vehicle without power transmission are disclosed. In the control apparatus and method for the pole change motor is electrically changed between an n number of poles and a 2n number of the poles (n=2, 4, - - - ) so as to secure an output torque of the pole change induction motor in a constant driving mode with a high rotation speed of the induction motor without increase in a dimension of either of the induction motor or an inverter associated with the pole change induction motor and without occurrence in a torque variation. In a preferred embodiment, two channels of exciting and torque instructions and slip frequency generators (current instruction calculating blocks and current control systems) are provided for the n number of pole driving and 2n number of pole driving.

Abstract: To extend an operable range of a hybrid excitation type permanent magnet synchronous motor having a field of a permanent magnet and a dc excitation coil, magnetic flux of the field is controlled so as to keep constant when a rotation speed of the motor is smaller than a predetermined base speed and so as to change in reverse proportion with the rotation speed of the motor when the rotation speed is larger than the predetermined base speed. Electric current and voltage to an armature of the motor is controlled such that a current ratio of a direct-axis component and a quadrature-axis component which components are obtained by dividing an electric current to the armature coil into the direct-axis component and the quadrature-axis component relative to the voltage induced in the armature coil, is kept constant.