Abb Schweiz Ag

Andrey Kalygin

Christian Stulz

Christof Gutscher

Mate Jelavic

Marc Rauer

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.

Method for starting a synchronous motor

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.

Starting an induction machine

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.

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Würenlingen, Switzerland

Andrey Kalygin