A method of measuring torque is provided in a six phase electrical motor which includes a motor-stator including two electrically independent stator winding arrangements which each have three combined windings such that the winding arrangements are symmetrical and offset by an angle to each other and such that each combined winding of the second stator arrangement has a corresponding combined winding in the first stator arrangement and offset thereto by an angle. The method includes a) determining the current in the three combined windings of the first stator arrangement and/or the current in the three combined windings of the second stator arrangement and b) determining the torque from the currents.

A method for operating an electrical circuit, wherein the electrical circuit includes a DC converter, an inverter and an electric machine, wherein the inverter is connected on the direct current side to the output of the DC converter and on the alternating current side to the electric machine, wherein the electric machine is operated using a torque specification and/or a rotational speed specification, wherein the level of the output voltage of the DC converter is set as a function of a current torque specification and/or a current rotational speed specification.

A method for the noise-reduced operation of a switched reluctance motor with a reluctance motor assembly. The assembly includes the switched reluctance motor; —a control and evaluation unit; —a data memory; —a current regulator; —a rotor angle sensor; and —a torque evaluator. The switched reluctance motor includes a stator, a rotor and motor coils. The size of the current applied to the motor coils is stored in a value table in the data memory for different rotor angles. An actual torque is detected, and a deviation between a setpoint torque and the determined actual torque is determined. On the basis thereof, the current values are recalculated. The recalculated current values are written into the value table and define the basis of the next run.

A method of controlling an electric motor includes receiving a duty cycle for the electric motor for delivering a target torque from the electric motor, generating a pulse train, and pulsing the electric motor with the generated pulse train. Generating the pulse train being at least partially based on the received duty cycle. The generated pulse train optimized to improve at least one of noise, vibration, or harshness of the electric motor when compared to a constant pulse frequency.

A motor drive device (200) includes: a power conversion circuit (204) that drives an AC motor; and a controller (203) that controls the power conversion circuit. The controller includes: a command current calculation unit (206) that generates a command current according to command torque for the AC motor; a current control unit (208) that performs feedback control for adjusting a current applied to the AC motor to the command current; and a control gain setting unit (207) that calculates a control gain used for the feedback control based on the command torque and sets the calculated control gain in the current control unit. The control gain setting unit performs control such that a time from a decrease of an absolute value of the command torque to switching of the control gain is longer than a time from an increase of the absolute value of the command torque to switching of the control gain. As a result, deterioration of control stability of motor torque during a transient response is avoided.

The invention related to a control method for operating a synchronous machine, the machine comprising an exciter connected to a synchronous generator and a controller (40) for controlling the machine field excitation. The method comprises the steps of predefining a stable operation torque derivative range within which a stable operation of the machine occurs, performing a torque measuring or calculating for the machine, calculating the derivative of said torque, determining whether the calculated torque derivative is within the predefined stable operation torque derivative range for the machine, and, if the torque derivative is not within the predefined stable operation torque derivative range, modifying the machine field excitation to bring the torque derivative within the predefined stable operation torque derivative range.

A control system for an electric motor powered by a battery can be configured to receive an input power or torque command corresponding to a commanded power or torque. The control system can be configured to determine if the battery is capable of supplying and/or permitted to supply the commanded power or torque over a time period based on a state of charge (SOC) of the battery. The control system can be configured such that if the battery is capable of supplying and/or permitted to supply the commanded power or torque over the time period, the control system outputs the input power or torque command, and such that if the battery is not capable of supplying and/or not permitted to supply the commanded power or torque over the time period, the control system outputs an available maximum power or torque command corresponding to an available maximum power or torque over the time period that is less than the commanded power or torque.

An apparatus for controlling an electric motor having a controller, a torque demand limit generator, and a drive stage. The controller may be arranged to receive as an input a torque demand signal indicative of the amount of torque demanded from the motor and to produce as an output a set of motor current demand signals. The drive stage may receive the motor current demand signals and is arranged to cause currents to flow in each phase of the motor as required to meet the demanded torque. The torque demand limit generator may be arranged to output a torque demand limit signal indicative of a torque demand limit above which the battery current would exceed one or more limits.

An electric motor driving system controls driving of an electric motor having windings of two or more phases each having open ends by using a pair of inverters. A control unit includes a first inverter control circuit that generates a first voltage instruction output to the first inverter based on a torque instruction and a second inverter control circuit that generates a second voltage instruction output to the second inverter based on the torque instruction. At least one of the inverter control circuits includes an electric power controller that controls allocation of electrical power supplied from a pair of power supplies to the pair of inverters, respectively, by either advancing or delaying an angle of a phase of each of vectors of voltage instructions in accordance with the target electric power instruction during execution of torque feedback control.

An electric motor control device includes a target torque setting unit setting target torque for each of a right-side control circuit and a left-side control circuit, and a failure occurrence determination unit determining whether there is a failure occurrence in at least one of the two control circuits. The target torque setting unit sets, in response to there being a failure occurrence in a failure control circuit that is one of the two control circuits and there being a no failure occurrence in a normal control circuit that is the other of the two control circuits, fail-safe torque which is lower than a normal value of the target torque as the target torque for the failure control circuit, and sets failure-time target torque which is lower than the normal value of the target torque and being higher than the fail-safe torque as the target torque for the normal control circuit.