One aspect of the invention relates to a control device (2) for starting up a synchronous electric motor (1) up to a predetermined threshold speed, comprising: a current regulator (4) that delivers a voltage setpoint (V #dq) in accordance with a regulation current setpoint (l #dq), a computing unit (5) for computing a current feedback. (Idq) in accordance with measurements of the phase currents (lu, Iv, Iw), an estimator (6) for estimating an angular position of the rotor (elec), in accordance with a difference between a reference stator flux vector (q) that depends on the feedback currents (Iq) and an adaptive stator flux vector (qv) that depends on the voltage setpoint (V.sup.#dq), on the feedback currents (Iq, Id), and on an estimated electrical speed (elec), a setpoint current modifier (7) that computes, when the estimated electrical speed (elec) is lower than the predetermined threshold speed, a regulator setpoint DC current (l.sup.#d) having a non-zero value.

A controller for a permanent magnet synchronous motor includes a first control loop having a first filter. The first filter has a back-EMF voltage vector input, a magnetic flux vector output with a constant phase shift that is independent of motor speed, and an amplitude response that is inversely proportional to rotor electrical frequency. The first control loop is configured to: generate an adjusted magnetic flux vector from the magnetic flux vector output by the first filter and compensate for the constant phase shift introduced by the first filter; estimate the rotor electrical frequency from the adjusted magnetic flux vector; and feedback a filtered version of the rotor electrical frequency estimate to the first filter as an estimation of the rotor electrical frequency.

A controller for a permanent magnet synchronous motor includes a first control loop having a first filter. The first filter has a back-EMF voltage vector input, a magnetic flux vector output with a constant phase shift that is independent of motor speed, and an amplitude response that is inversely proportional to rotor electrical frequency. The first control loop is configured to: generate an adjusted magnetic flux vector from the magnetic flux vector output by the first filter and compensate for the constant phase shift introduced by the first filter; estimate the rotor electrical frequency from the adjusted magnetic flux vector; and feedback a filtered version of the rotor electrical frequency estimate to the first filter as an estimation of the rotor electrical frequency.

A method for controlling a power converter system and a power converter system including a first power converter connected to a first stator winding of an induction motor having a rotor, the first stator winding and a second stator winding, and a second power converter connected to the second stator winding of the induction motor, the first power converter being configured to transmit a slip angle estimate to the second power converter, and the second power converter being configured to determine a slip angle reference on the basis of the slip angle estimate transmitted from the first power converter and a predetermined phase shift between the second stator winding and the first stator winding and to determine a rotor flux angle estimate on the basis of the determined slip angle reference and a mechanical angle of the rotor.

A method for controlling a power converter system and a power converter system including a first power converter connected to a first stator winding of an induction motor having a rotor, the first stator winding and a second stator winding, and a second power converter connected to the second stator winding of the induction motor, the first power converter being configured to transmit a slip angle estimate to the second power converter, and the second power converter being configured to determine a slip angle reference on the basis of the slip angle estimate transmitted from the first power converter and a predetermined phase shift between the second stator winding and the first stator winding and to determine a rotor flux angle estimate on the basis of the determined slip angle reference and a mechanical angle of the rotor.

A drive system includes an electric motor and a converter that feeds the electric motor. A cable electrically connects the electric motor to the converter and has first electrical lines, a second electrical line, and third electrical lines. A voltage detection device arranged on the first cable end detects a voltage present between the second electrical line and a further electrical line, e.g., a measuring line. The further electrical line is one of the first electrical lines or one of the third electrical lines, and the further electrical line is electrically connected to the second electrical line on the second cable end. The current flowing through the further electrical line is detected by a current detection device, and a resistance value is determined from the detected voltage and the detected current and is provided to a control unit of the converter.

A drive system includes an electric motor and a converter that feeds the electric motor. A cable electrically connects the electric motor to the converter and has first electrical lines, a second electrical line, and third electrical lines. A voltage detection device arranged on the first cable end detects a voltage present between the second electrical line and a further electrical line, e.g., a measuring line. The further electrical line is one of the first electrical lines or one of the third electrical lines, and the further electrical line is electrically connected to the second electrical line on the second cable end. The current flowing through the further electrical line is detected by a current detection device, and a resistance value is determined from the detected voltage and the detected current and is provided to a control unit of the converter.

An electric drive system includes an electric machine having a stator assembly and a rotor assembly. The stator assembly has a plurality of multi-phase stator windings, including a first stator winding and a second stator winding. A first inverter is adapted to feed the first stator winding. A second inverter is adapted to feed the second stator winding. The rotor assembly includes rotor windings having a single phase. A controller is configured to selectively command excitation of the rotor windings with a pulsed field current such that a direct-axis (d-axis) stator flux linkage is generated. A d-axis stator voltage is induced in the first stator winding and the second stator winding by the d-axis stator flux linkage. Pulsed power transfer is enabled through interaction of the d-axis stator voltage and respective d-axis winding currents in the first stator winding and the second stator winding.

An electric drive system includes an electric machine having a stator assembly and a rotor assembly. The stator assembly has a plurality of multi-phase stator windings, including a first stator winding and a second stator winding. A first inverter is adapted to feed the first stator winding. A second inverter is adapted to feed the second stator winding. The rotor assembly includes rotor windings having a single phase. A controller is configured to selectively command excitation of the rotor windings with a pulsed field current such that a direct-axis (d-axis) stator flux linkage is generated. A d-axis stator voltage is induced in the first stator winding and the second stator winding by the d-axis stator flux linkage. Pulsed power transfer is enabled through interaction of the d-axis stator voltage and respective d-axis winding currents in the first stator winding and the second stator winding.

A controller for a permanent magnet synchronous motor includes a first control loop having a first filter. The first filter has a back-EMF voltage vector input, a magnetic flux vector output with a constant phase shift that is independent of motor speed, and an amplitude response that is inversely proportional to rotor electrical frequency. The first control loop is configured to: generate an adjusted magnetic flux vector from the magnetic flux vector output by the first filter and compensate for the constant phase shift introduced by the first filter; estimate the rotor electrical frequency from the adjusted magnetic flux vector; and feedback a filtered version of the rotor electrical frequency estimate to the first filter as an estimation of the rotor electrical frequency.