A rotating electric machine includes an armature that has an armature winding of multiple phases. The armature winding is configured by a conductor being wound. The conductor is configured by a plurality of wires covered by an insulation coating in a state in which the plurality of wires are bundled. Each of the plurality of wires includes a conductor body configured to permit flow of a current, and a fusion layer that covers a surface of the conductor body. The fusion layer is configured to be thinner than the insulation coating. In the state in which the plurality of wires are bundled, fusion layers of the plurality of wires are fused and in contact with one another. A coefficient of linear expansion of the fusion layer differs from a coefficient of linear expansion of the insulation coating.

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 motor drive system and method for determining an optimized efficiency of the motor drive system are provided. The motor drive system includes a system controller, a motor drive having includes an inverter configured to generate the AC power upon one or more motor leads, and an electric motor, which is to convert the AC power from the motor leads to rotational energy. A dynamometer may include a load coupled to the shaft and sensors to measure to measure operating characteristics such as torque and speed of the electric motor. The system controller is configured to generate a lookup table, with an entry describing an output current command for operating the inverter and the motor at a maximum system efficiency for a given combination rotational speed and output torque. Motor temperature may also be measured and used as an additional index into the lookup table.

A rotary current machine system and method for controlling an electric rotary current machine, in particular an induction machine, having a rotor, a stator and at least two phase windings is disclosed. At least one electrical signal, in particular a voltage signal, is applied to at least one phase winding, preferably all phase windings, of the rotary current machine, and the current waveform in the at least one phase winding is measured. An intermodulation signal component, induced in the rotary current machine by slotting effects and magnetic saturation effects, which is determined from the current waveform measured in the at least one phase winding, is used for controlling the rotary current machine.

The invention relates to a method for controlling an inverter which is electrically connected to an electric motor, having the following steps: defining a modulated voltage (S1) for the inverter, said voltage being based on a first switching frequency, for operating the electric motor with a current, wherein the current has an electric frequency; determining the electric frequency (S2); changing the first switching frequency (S4) on which the modulated voltage is based to a second switching frequency if a value pair consisting of electric frequency and first switching frequency, or a value pair consisting of electric frequency and a sideband of the first switching frequency, is within at least one defined disturbance range (S3).

This power conversion device includes: a current detection unit for detecting current flowing through a rotary electric machine; a switching pattern determination unit for determining a switching pattern on the basis of the detected current, a current prediction value, a current command value, and a current harmonic command value; and a power conversion unit for outputting AC power to the rotary electric machine in accordance with the switching pattern, wherein the switching pattern determination unit determines the switching pattern so that the current value follows the current command value and the current harmonic becomes equal to or smaller than a limit value.

A method for adapting the control parameters of an electric traction machine being a permanent magnetic synchronous motor, PMSM, the method comprising providing the flux linkage of the permanent magnets, PM flux, in the PMSM; performing a stand still characterisation of the PMSM to estimate linked magnetic flux as a function of current; adding the PM flux to the estimated linked magnetic flux to provide a flux characteristic of the PMSM; adapting the control parameters of the PMSM based on the flux characteristic.

According to an aspect, there is provided an apparatus for performing angular position error estimation. The apparatus operates (601) a synchronous motor (111) according to a pre-defined pulsating torque signal using a sensorless vector control method with high-frequency voltage injection. The pre-defined pulsating torque signal has a zero mean and corresponds to a torque operating point. The apparatus measures (602) a first value of an estimated angular position at a first time instance corresponding substantially to an end point of the pre-defined pulsating torque signal and second values of the estimated angular position and an estimated angular speed at a second time instance occurring after the first time instance. Based on the measured values, the apparatus estimates (603) an error in the estimated angular position and stores (604) the error to a lookup table. After performing said steps for one or more pre-defined pulsating torque signals, the apparatus operates (607) the synchronous motor (111) using the lookup table for angular position error correction.

The invention relates to a method for controlling an inverter which is electrically connected to an electric motor, having the following steps: defining a modulated voltage (S1) for the inverter, said voltage being based on a first switching frequency, for operating the electric motor with a current, wherein the current has an electric frequency; determining the electric frequency (S2); changing the first switching frequency (S4) on which the modulated voltage is based to a second switching frequency if a value pair consisting of electric frequency and first switching frequency, or a value pair consisting of electric frequency and a sideband of the first switching frequency, is within at least one defined disturbance range (S3).

Methods and apparatus to control a three-phase BLDC motor with a curve transformer having an index value for each stored input value and output value for providing stored corner points for outputs of the curve transformer. The curve transformer can output interpolated data for input data between adjacent ones of the input values.