Abstract: A method for starting a synchronous motor is provided. The synchronous motor includes a rotor for creating a first magnetic field and a stator with stator windings connected to an electrical energy converter for converting a supply voltage into a stator voltage to be applied to the stator windings to create a rotating second magnetic field interacting with the first magnetic field. The method includes applying reference stator voltages to the stator windings, where the reference stator voltages are determined from a reference current vector and a reference rotor speed, measuring stator currents, calculating an estimated rotor speed and rotor position from the applied stator voltages and the measured stator currents, calculating a speed error by subtracting the estimated rotor speed from the reference rotor speed, determining a reference torque producing current component from the speed error, and modifying the reference current vector with the reference torque producing current component.

Abstract: The invention relates to a method for starting a synchronous motor. The synchronous motor includes a rotor for creating a first magnetic field and a stator with stator windings connected to an electrical energy converter for converting a supply voltage into a stator voltage to be applied to the stator windings to create a rotating second magnetic field interacting with the first magnetic field.

Abstract: A method for starting an induction machine without residual flux includes: scanning a state of the induction machine with different stator frequencies by controlling a supply voltage applied to the induction machine; determining whether a slip value, being a difference between a rotor frequency and a stator frequency, is within a slip interval; and, when it has been determined that the slip value is in the slip interval, regulating the slip value towards zero and magnetising the machine to the required level.

Abstract: A method for starting an induction machine without residual flux includes: scanning a state of the induction machine with different stator frequencies by controlling a supply voltage applied to the induction machine; determining whether a slip value, being a difference between a rotor frequency and a stator frequency, is within a slip interval; and, when it has been determined that the slip value is in the slip interval, regulating the slip value towards zero and magnetising the machine to the required level.

Abstract: An electrical multi-phase converter and method for controlling an electrical multi-phase converter is disclosed. In one form a method provides for controlling the electrical multi-phase converter comprises: determining at least two supply voltages for the at least two converter cells of the at least two phase branches; determining a potential zone for each phase branch based on the at least one supply voltage of the at least one converter cell of the phase branch, the potential zone bounding a possible actual phase voltage producible by the phase branch; receiving a reference voltage for each phase branch; and, if the reference voltage for a phase branch is not within the potential zone of the phase branch, setting the reference voltage to a bound of the potential zone and shifting reference voltages of other phase branches, wherein the reference voltages are set and shifted such that a minimal common mode voltage between the output voltages of the multi-phase converter is generated.

Abstract: An electrical multi-phase converter and method for controlling an electrical multi-phase converter is disclosed. In one form a method provides for controlling the electrical multi-phase converter comprises: determining at least two supply voltages for the at least two converter cells of the at least two phase branches; determining a potential zone for each phase branch based on the at least one supply voltage of the at least one converter cell of the phase branch, the potential zone bounding a possible actual phase voltage producible by the phase branch; receiving a reference voltage for each phase branch; and, if the reference voltage for a phase branch is not within the potential zone of the phase branch, setting the reference voltage to a bound of the potential zone and shifting reference voltages of other phase branches, wherein the reference voltages are set and shifted such that a minimal common mode voltage between the output voltages of the multi-phase converter is generated.