A method of starting a sensorless BLDC motor. The method includes: providing a stator flux rotating coordinate system including a ds-axis and a qs-axis, selecting a voltage Vds on the ds-axis, allowing a voltage Vqs on the qs-axis to be 0, and resetting a to-be-started motor to a preset position; providing a flux to the motor, allowing the current Iqs on the qs-axis to rise, maintaining the flux constant, calculating a real-time torque T1 according to the torque/current closed loop on the qs-axis, comparing a preset starting torque T0 with the real-time torque T1, performing the torque/current closed-loop control until the real-time torque T1 reaches the preset starting torque T0; and continuously raising the real-time torque according to the torque/current closed loop to operate a load, measuring a real-time rotation speed V1, comparing a preset starting rotation speed V0 with the measured real-time rotation speed V1.

A method for controlling a three-phase electrical converter including: selecting a three-phase optimized pulse pattern from a table of pre-computed optimized pulse patterns based on a reference flux; determining a two-component optimal flux from the optimized pulse pattern and determine a one-component optimal third variable; determining a two-component flux error from a difference of the optimal flux and an estimated flux estimated based on measurements in the electrical converter; determining a one-component third variable error from a difference of the optimal third variable and an estimated third variable; modifying the optimized pulse pattern by time-shifting switching instants of the optimized pulse pattern such that a cost function depending on the time-shifts is minimized, wherein the cost function aincludes a flux error term and a third variable error term, wherein the flux error term is based on a difference of the flux error and a flux correction function providing a flux correction based on the time-shifts and the third variable error term is based on a difference of the third variable error and a third variable correction function providing a third variable correction based on the time-shifts; and applying the modified optimized pulse pattern to the electrical converter.

A device for estimating a rotation speed and/or a direction of rotation of an induction machine is presented. The device controls stator voltages (uu, uv, uw) of the induction machine so that a voltage space-vector constituted by the stator voltages has a fixed direction and a current space-vector constituted by stator currents (iu, iv, iw) of the induction machine has a pre-determined length or a predetermined d-component. The rotation speed and/or the direction of rotation is/are estimated based on a waveform of a q-component of the current space-vector, where the d-component of the current space-vector is parallel with the voltage space-vector and the q-component of the current space-vector is perpendicular to the voltage space-vector. The device is usable when the induction machine does not have enough magnetic flux for flux-based determination of the rotation speed and/or the direction of rotation.

A system and method for suppressing serpentine instability of a railway vehicle, comprising a serpentine warning and control module for determining whether a bogie is in a state of serpentine instability; a traction motor speed control system for controlling a rotation speed of a traction motor according to a determination from the serpentine warning and control module; a signal output end of the serpentine warning and control module is connected with the traction motor speed control system. In the present disclosure, it extracts the serpentine characteristic wave from the transverse acceleration of the bogie and calculates the vibration non-linear index according to the extracted serpentine non-linear characteristic to judge whether the bogie is in a state of serpentine instability, and controls a direct torque of the traction system through the DTC control module.

A brushless, self-excited synchronous field winding machine is presented. The AC stator is configured with four or more phases to produce independent magnetic fields at different spatial harmonics. Windings in the rotor are configured to magnetically couple to the different spatial harmonics produced by the AC stator. More specifically, an oscillating field generated by the stator magnetically couples to the excitation winding on the rotor. This induces an AC voltage which results in current flowing through the field winding of the rotor. The magnitude of the field current is therefore controlled by the magnitude of the oscillating field. The AC stator also produces a magnetic field at a different spatial harmonic which magnetically couples to field winding of the rotor. This component will interact with the field current to produce torque. With this approach, the power density of the electric machine is significantly increased as compared to conventional field winding designs.

A brushless, self-excited synchronous field winding machine is presented. The AC stator is configured with four or more phases to produce independent magnetic fields at different spatial harmonics. Windings in the rotor are configured to magnetically couple to the different spatial harmonics produced by the AC stator. More specifically, an oscillating field generated by the stator magnetically couples to the excitation winding on the rotor. This induces an AC voltage which results in current flowing through the field winding of the rotor. The magnitude of the field current is therefore controlled by the magnitude of the oscillating field. The AC stator also produces a magnetic field at a different spatial harmonic which magnetically couples to field winding of the rotor. This component will interact with the field current to produce torque. With this approach, the power density of the electric machine is significantly increased as compared to conventional field winding designs.

The disclosure relates to an electrical drive device having: an inverter including an inverter unit for each phase; a control unit configured to control the inverter units by application of vector control; and a rotating electrical machine having a stator that includes a plurality of phase windings connected to the inverter units. Each of the phase windings includes a first part-winding and an electrically isolated second part-winding. The inverter units include a first phase module and a second phase module. The phase modules deliver the electrical phase assigned to the respective inverter unit in a separate and a mutually electrically isolated manner. The first part-winding is electrically connected to the first phase module and the second part-winding is electrically connected to the second phase module.

The disclosure relates to an electrical drive device having: an inverter including an inverter unit for each phase; a control unit configured to control the inverter units by application of vector control; and a rotating electrical machine having a stator that includes a plurality of phase windings connected to the inverter units. Each of the phase windings includes a first part-winding and an electrically isolated second part-winding. The inverter units include a first phase module and a second phase module. The phase modules deliver the electrical phase assigned to the respective inverter unit in a separate and a mutually electrically isolated manner. The first part-winding is electrically connected to the first phase module and the second part-winding is electrically connected to the second phase module.

Methods and systems for real-time, in-service, non-intrusive condition monitoring of turn-to-turn faults (TTFs) of an induction motor stator in a drive system. A time-domain-based signal processing technique, mathematical morphology, can be used for condition monitoring based on the radiated electromagnetic (EM) field from the induction motor. The vector control technique implemented to drive the induction motor can be direct torque control, and the mathematical morphology technique can detect incipient TTFs based on the radiated magnetic field.

Methods and systems for real-time, in-service, non-intrusive condition monitoring of turn-to-turn faults (TTFs) of an induction motor stator in a drive system. A time-domain-based signal processing technique, mathematical morphology, can be used for condition monitoring based on the radiated electromagnetic (EM) field from the induction motor. The vector control technique implemented to drive the induction motor can be direct torque control, and the mathematical morphology technique can detect incipient TTFs based on the radiated magnetic field.