The control device includes: a unit for receiving, for a time period, phase voltage setpoints forming a setpoint vector in vector space; a unit for selecting at least N+1 states of the inverter which are associated, respectively, with at least N+1 predetermined vectors (M1 . . . M27) defining a volume in the vector space (Esp) containing the setpoint vector; a unit for controlling the inverter, over the time period, in order to place it successively in the selected states so that it substantially applies, on average over the time period, the phase voltage setpoints. The at least N+1 states of the inverter are selected from among groups of at least N+1 states of the inverter, the at least N+1 states of the inverter of at least one of the groups being associated, respectively, with at least N+1 predetermined vectors (M1 . . . M27), at least N of which are formed by predetermined zero-sum phase voltages and at least one of which is formed by predetermined nonzero-sum phase voltages.

In the fault-tolerant direct thrust-force control (FT-DTC) method, the generalized Clarke transform matrix and its inverse matrix are derived according to the fault-tolerant phase currents. The stator fluxes in - plane are deduced based on these. Based on the requirement of circular stator flux trajectory, virtual stator fluxes are defined, and then compensatory voltages in the - plane are obtained. Actual stator voltages in the - plane are calculated by modulation function of voltage source inverter. Combining with the compensatory voltages, the actual stator voltages and the stator currents, the virtual stator fluxes and the thrust-force are estimated by the flux and thrust-force observers. The thrust-force reference, the stator flux amplitude reference, the observed thrust-force and virtual stator flux are applied to predict virtual stator voltage references. The actual stator voltage references is calculated according to virtual voltage references and compensatory voltages, and are fed to voltage source inverter.

In the fault-tolerant direct thrust-force control (FT-DTC) method, the generalized Clarke transform matrix and its inverse matrix are derived according to the fault-tolerant phase currents. The stator fluxes in - plane are deduced based on these. Based on the requirement of circular stator flux trajectory, virtual stator fluxes are defined, and then compensatory voltages in the - plane are obtained. Actual stator voltages in the - plane are calculated by modulation function of voltage source inverter. Combining with the compensatory voltages, the actual stator voltages and the stator currents, the virtual stator fluxes and the thrust-force are estimated by the flux and thrust-force observers. The thrust-force reference, the stator flux amplitude reference, the observed thrust-force and virtual stator flux are applied to predict virtual stator voltage references. The actual stator voltage references is calculated according to virtual voltage references and compensatory voltages, and are fed to voltage source inverter.

A method for controlling a variable speed drive arranged for powering an electric motor, the variable speed drive comprising a power part and a control part. The method comprises a preliminary phase of storing a set of predetermined levels of flux of the electric motor. Then, during a current phase, the method comprises selecting a level of flux from among the set of predetermined levels of flux and controlling the power part of the variable speed drive based on the selected level of flux as reference value.

A method for controlling a variable speed drive arranged for powering an electric motor, the variable speed drive comprising a power part and a control part. The method comprises a preliminary phase of storing a set of predetermined levels of flux of the electric motor. Then, during a current phase, the method comprises selecting a level of flux from among the set of predetermined levels of flux and controlling the power part of the variable speed drive based on the selected level of flux as reference value.

A rotary electric machine is equipped with a stator and a rotor. The rotor has a d-axis magnetic circuit that is produced by a magnetomotive force of a field winding, and magnet magnetic circuits that are produced by a magnetic force of permanent magnets. The d-axis magnetic circuit and a q-axis magnetic circuit have at least a part thereof that is common to both. The permeance of the d-axis magnetic circuit is smaller than the permeance of the q-axis magnetic circuit, when a load is being applied to the rotor. A control apparatus of the rotary electric machine has a switching circuit that controls the field current in the field winding, and a control section that makes the switching frequency of the switching circuit become higher when the field current is above a threshold value than when the field current is less than or equal to the threshold value.

A rotary electric machine is equipped with a stator and a rotor. The rotor has a d-axis magnetic circuit that is produced by a magnetomotive force of a field winding, and magnet magnetic circuits that are produced by a magnetic force of permanent magnets. The d-axis magnetic circuit and a q-axis magnetic circuit have at least a part thereof that is common to both. The permeance of the d-axis magnetic circuit is smaller than the permeance of the q-axis magnetic circuit, when a load is being applied to the rotor. A control apparatus of the rotary electric machine has a switching circuit that controls the field current in the field winding, and a control section that makes the switching frequency of the switching circuit become higher when the field current is above a threshold value than when the field current is less than or equal to the threshold value.

An inverter control device that controls an inverter as a control target, the inverter being connected to a direct-current power supply and connected to an alternating-current rotating electrical machine so as to convert power between direct current and alternating current of a plurality of phases, and the inverter having an arm for each alternating-current phase, the arm including a series circuit of an upper-stage switching element and a lower-stage switching element, the inverter control device including an electronic control unit.

An inverter control device that controls an inverter as a control target, the inverter being connected to a direct-current power supply and connected to an alternating-current rotating electrical machine so as to convert power between direct current and alternating current of a plurality of phases, and the inverter having an arm for each alternating-current phase, the arm including a series circuit of an upper-stage switching element and a lower-stage switching element, the inverter control device including an electronic control unit.

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.