A motor controller comprises a switch circuit, a pre-driver, a duty cycle control circuit, a current limit circuit, a pulse width modulation control unit, and a resistor. The motor controller is configured to drive a motor, where the motor has a motor coil and a maximum rated current. The switch circuit is configured to supply a motor current to the motor coil. The pre-driver generates a plurality of driving signals to control the switch circuit. The current limit circuit may store a current limit graph. The motor controller attains a function of maintaining a fixed output power by a plurality of current limit values, where each of the current limit values is less than or equal to the maximum rated current.

A motor controller comprises a switch circuit, a pre-driver, a duty cycle control circuit, a current limit circuit, a pulse width modulation control unit, and a resistor. The motor controller is configured to drive a motor, where the motor has a motor coil and a maximum rated current. The switch circuit is configured to supply a motor current to the motor coil. The pre-driver generates a plurality of driving signals to control the switch circuit. The current limit circuit may store a current limit graph. The motor controller attains a function of maintaining a fixed output power by a plurality of current limit values, where each of the current limit values is less than or equal to the maximum rated current.

According to an embodiment, an electric motor drive device includes an electric motor, a main circuit, a current sensor, and a control unit. The electric motor has a plurality of windings. The main circuit transforms power of an alternating current (AC) power supply into AC power and supplies the AC power to each of the plurality of windings. The current sensor detects a load current flowing through each of the plurality of windings. The control unit controls the main circuit on the basis of a current value detected by the current sensor. The control unit controls an amount of power to be supplied from the main circuit to the electric motor on the basis of an amplitude of the load current associated with detection of an undervoltage state of the AC power supply in a state in which the main circuit uses a conversion rule in which an index value for the amplitude of the load current flowing through the plurality of windings is defined.

The present invention provides control of a synchronous machine with non-sinusoidal current-voltage profiles. The synchronous machine is controlled in a field-oriented coordinate system. In this case, the transformation between field-oriented coordinate system and stator-oriented coordinate system is effected by specific, adapted transformations which take account of the non-sinusoidal signal profiles during the driving of the synchronous machine, such that the latter correspond to current-voltage profiles progressing in a constant fashion in the field-oriented coordinate system. What is achieved thereby is that the non-sinusoidal current-voltage profiles need not be taken into account in any way in the design of the control system in the field-oriented coordinate system.

A system for providing power to one or more loads includes a plurality of power converters where each power converter is configured to be arranged in a parallel configuration with one or more additional power converters so as to provide power to the one or more loads. The system also includes a central controller configured to receive a plurality of local voltage reference values from each of the power converters, output a global voltage reference value based on the local voltage reference values, and transmit the global voltage reference value to each of the power converters.

A method and apparatus for quasi-sensorless adaptive control of a high rotor pole switched-reluctance motor (HRSRM). The method comprises the steps of: applying a voltage pulse to an inactive phase winding and measuring current response in each inactive winding. Motor index pulses are used for speed calculation and to establish a time base. Slope of the current is continuously monitored which allows the shaft speed to be updated multiple times and to track any change in speed and fix the dwell angle based on the shaft speed. The apparatus for quasi-sensorless control of a high rotor pole switched-reluctance motor (HRSRM) comprises a switched-reluctance motor having a stator and a rotor, a three-phase inverter controlled by a processor connected to the switched-reluctance motor, a load and a converter.

A motor controller includes a current controller configured to generate control signals for driving a permanent magnet synchronous motor (PMSM), where the current controller is configured to measure voltage information and current information of the PMSM; a power constant controller configured to receive the voltage information and the current information, and generate a first target speed based on a target power of the PMSM and based on the voltage information and the current information; first signal generator configured to generate a second target speed; a speed constant controller coupled between the power constant controller and the current controller, wherein the speed constant controller is configured to switchably receive the first target speed and the second target speed, and regulate a motor speed of the PMSM based on the received first target speed or the received second target speed.

A method for modulating a torque ripple and/or a radial force of a three-phase current-operated electric machine includes selecting at least one of a harmonic (HM1_EM) in a torque of the electric machine and a harmonic (HM_X) of a load coupled to the electric machine. The at least one selected harmonic (HM1_EM, HM_X) is modulated by applying the at least one selected harmonic (HM1_EM, HM_X) to a d-current and/or a q-current or to a variable correlated therewith in order to generate a setpoint variable for driving the electric machine A phase angle (φd,k2φqk) of at least one of a harmonic (H.sub.Id) in the d-current and harmonic (H1q) in the q-current is at least temporarily set to be different with respect to a rotor angle,such that φ.sub.d,k ≠φ.sub.q,k applies.

A servo direct-current feeder system can reduce an oscillating voltage across a power feeding path. The servo direct-current feeder system includes a direct-current power supply, a plurality of motor controllers that each control a servomotor, and a power feeding path that distributes power from the direct-current power supply to the plurality of motor controllers. Each of the plurality of motor controllers includes a current control loop unit that controls a current flowing through the servomotor. The current loop unit includes a current control loop including a notch filter having a center frequency corresponding to a frequency to occur from an oscillating voltage across the power feeding path.

A method for controlling a converter, preferably a generator-side active rectifier of a power converter of a wind power installation. The method includes specifying a target value for the converter, specifying a carrier signal for the converter, capturing an actual value, determining a distortion variable from the target value and the actual value and determining driver signals for the converter on the basis of the distortion variable and the carrier signal.