According to one embodiment, a driving device includes a voltage controller, a parameter setter, and a phase adjuster. The voltage controller causes an electric power converter to apply a drive voltage to the electric motor, the electric power converter converting input electric power to A/C electric power having desired voltage and frequency and supplying the converted electric power to an electric motor. The parameter setter sets at least one of a rotation speed of the electric motor and a parameter related to the rotation speed as speed information. The phase adjuster adjusts a phase of the drive voltage in such a manner that an index calculated based on a current flowing in the electric motor and the speed information set in the parameter setter becomes smaller.

According to one embodiment, a driving device includes a voltage controller, a parameter setter, and a phase adjuster. The voltage controller causes an electric power converter to apply a drive voltage to the electric motor, the electric power converter converting input electric power to A/C electric power having desired voltage and frequency and supplying the converted electric power to an electric motor. The parameter setter sets at least one of a rotation speed of the electric motor and a parameter related to the rotation speed as speed information. The phase adjuster adjusts a phase of the drive voltage in such a manner that an index calculated based on a current flowing in the electric motor and the speed information set in the parameter setter becomes smaller.

A commutation error compensation method for an electric motor includes: when a rotor, that has not been corrected, in an electric motor rotates in a set direction, collecting a position signal and a three-phase current signal of the rotor, wherein the position signal of the rotor represents the rotation angle of the rotor; filtering processing on the three-phase current signal to obtain a fundamental component of the three-phase current signal, and determining a position error compensation signal of the electric motor on the basis of the fundamental component of the three-phase current signal; determining an ideal phase interval of the rotor according to the position error compensation signal and the position signal of the rotor; and determining an adjustment method for the rotor of the electric motor according to the ideal phase interval of the rotor, and commutating the rotor of the electric motor according to the adjustment method.

A commutation error compensation method for an electric motor includes: when a rotor, that has not been corrected, in an electric motor rotates in a set direction, collecting a position signal and a three-phase current signal of the rotor, wherein the position signal of the rotor represents the rotation angle of the rotor; filtering processing on the three-phase current signal to obtain a fundamental component of the three-phase current signal, and determining a position error compensation signal of the electric motor on the basis of the fundamental component of the three-phase current signal; determining an ideal phase interval of the rotor according to the position error compensation signal and the position signal of the rotor; and determining an adjustment method for the rotor of the electric motor according to the ideal phase interval of the rotor, and commutating the rotor of the electric motor according to the adjustment method.

A vector control method and system of a permanent magnet motor (PMM) comprising a step of counting parameters of components of a power cable line (channel) (PCL), between the PMM and a regulated voltage source (RVS), wherein counting at least parameters of an inductance, a resistance and a capacitance of elements of the PCL. Providing voltage sag compensation mode by controlling the RVS DC-link voltage parameter using a voltage sag control unit, and controlling the PMM frequency parameter by changing current and/or voltage PMM parameters counting changes in the RVS DC-link voltage parameter and a nominal power parameter of the PMM.

A vector control method and system of a permanent magnet motor (PMM) comprising a step of counting parameters of components of a power cable line (channel) (PCL), between the PMM and a regulated voltage source (RVS), wherein counting at least parameters of an inductance, a resistance and a capacitance of elements of the PCL. Providing voltage sag compensation mode by controlling the RVS DC-link voltage parameter using a voltage sag control unit, and controlling the PMM frequency parameter by changing current and/or voltage PMM parameters counting changes in the RVS DC-link voltage parameter and a nominal power parameter of the PMM.

A rotary current machine system and method for controlling an electric rotary current machine, in particular an induction machine, having a rotor, a stator and at least two phase windings is disclosed. At least one electrical signal, in particular a voltage signal, is applied to at least one phase winding, preferably all phase windings, of the rotary current machine, and the current waveform in the at least one phase winding is measured. An intermodulation signal component, induced in the rotary current machine by slotting effects and magnetic saturation effects, which is determined from the current waveform measured in the at least one phase winding, is used for controlling the rotary current machine.

A rotary current machine system and method for controlling an electric rotary current machine, in particular an induction machine, having a rotor, a stator and at least two phase windings is disclosed. At least one electrical signal, in particular a voltage signal, is applied to at least one phase winding, preferably all phase windings, of the rotary current machine, and the current waveform in the at least one phase winding is measured. An intermodulation signal component, induced in the rotary current machine by slotting effects and magnetic saturation effects, which is determined from the current waveform measured in the at least one phase winding, is used for controlling the rotary current machine.

A motor driving method includes steps of: at an open loop phase and in response to a motor being operated under a steady-state, calculating an angle difference between an estimation coordinate axis of the motor and an actual coordinate axis by a controller, according to an estimation voltage value, an estimation current value and at least one electrical parameter feedback from the motor and in reference with the estimation coordinate axis of the motor; calculating an actual current value in reference with the actual coordinate axis according to the angle difference by the controller; calculating a load torque estimation value associated with the motor according to the actual current value by the controller; and, in response to the open loop phase being switched to a close loop phase, compensating an output torque of the motor according to the load torque estimation value by the controller.

A motor driving method includes steps of: at an open loop phase and in response to a motor being operated under a steady-state, calculating an angle difference between an estimation coordinate axis of the motor and an actual coordinate axis by a controller, according to an estimation voltage value, an estimation current value and at least one electrical parameter feedback from the motor and in reference with the estimation coordinate axis of the motor; calculating an actual current value in reference with the actual coordinate axis according to the angle difference by the controller; calculating a load torque estimation value associated with the motor according to the actual current value by the controller; and, in response to the open loop phase being switched to a close loop phase, compensating an output torque of the motor according to the load torque estimation value by the controller.