In a method for detecting a motor phase fault of a motor arrangement, the motor phases of which are connected to a drive circuit having a DC voltage intermediate circuit and an inverter. A motor phase voltage at at least one of the motor phases with respect to a reference potential is captured while the inverter is switched off; and a voltage profile of the captured motor phase voltage is used to determine whether there is a motor phase fault on one of the motor phases of the motor arrangement.

A turboelectric distributed propulsion based on brushless doubly-fed machines (BDFMs) is provided, which minimizes power conversion, enhances mechanical reliability, and strengthens fault-tolerance capability of a DC-based propulsion system. A turboelectric distributed propulsion (TeDP) architecture using BDFMs for aviation applications, and a designed BDFM, inverter, and controller are provided. Simulations and systems are also provided.

A turboelectric distributed propulsion based on brushless doubly-fed machines (BDFMs) is provided, which minimizes power conversion, enhances mechanical reliability, and strengthens fault-tolerance capability of a DC-based propulsion system. A turboelectric distributed propulsion (TeDP) architecture using BDFMs for aviation applications, and a designed BDFM, inverter, and controller are provided. Simulations and systems are also provided.

A variable frequency motor drive comprises a converter including a rectifier having an input for connection to an AC power source and converting the AC power to DC power. A DC bus is connected to the rectifier circuit. At least one bus capacitor is across the DC bus. An inverter receives DC power from the DC bus and converts the DC power to AC power to drive a motor. A controller is operatively connected to the converter. The controller comprises a speed control controlling the inverter responsive to a speed command to maintain a desired motor speed. A speed foldback control measures DC bus ripple voltage and regulates the speed command responsive to the measured DC bus ripple voltage.

An inverter controller is provided. The controller according to an exemplary embodiment of the present disclosure generates a compensation voltage to compensate an inverter command voltage using motor torque current and motor information, and apply the compensation voltage to the command voltage.

When a rotational difference is generated between a left driving wheel and a right driving wheel, by controlling the frequency f0 of alternating currents to be fed to stator windings of first and second induction machines by a shared inverter, torque distribution to the left driving wheel and the right driving wheel is controlled.

Object of the present disclosure is to improve accuracy of over-temperature protection of an electric motor. A control device controls an inverter main circuit for driving the electric motor. An electric power conversion circuit controller acquires DC voltage input to the inverter main circuit, output voltage of the inverter main circuit, motor amperage of current flowing through the electric motor, and motor frequencies indicating rotation rate of the electric motor. Based on at least one of the DC voltage, output voltage, motor amperage and motor frequencies, a motor loss estimator calculates a stator loss and rotor loss, each including fundamental and harmonic losses of the electric motor. Based on the inverter output voltage, stator loss and rotor loss, the electric power conversion circuit controller outputs an actual control value for control of the inverter main circuit.

Systems and techniques detecting a reverse current are disclosed. An apparatus comprises a switching circuit coupled to a load and a reference node. The switching circuit may be capable of conducting a reverse current from the reference node to the load when a voltage at the load is lower than a voltage at the reference node. A voltage source has a first terminal coupled to the load, a second terminal configured to follow a voltage at the load, and produces a voltage proportional to a voltage drop across the switching circuit. A comparator circuit is coupled to compare a voltage at the second terminal of the voltage source to the voltage at the reference node and configured to indicate when the reverse current has a magnitude greater than a predetermined threshold.

At least one example embodiment discloses a method of controlling an alternating current (ac) machine. The method includes determining or retrieving a current limit for the ac machine, determining a characterized peak current value based on a voltage-to-speed ratio of the ac machine, determining current command values for the ac machine based on at least one of the torque command limit and a torque command for the ac machine, determining current command values for the ac machine based on the torque command limit and controlling the ac machine based on the current command values.

The invention relates an electrical cleaning and care appliance, pressure alarming method and apparatus for the appliance. Transducer elastic members of the appliance engage in resonance oscillation motion with bending strain characteristics, are symmetrically distributed on the left and right sides of the longitudinal axis (L.sub.2) of a drive shaft, and have approximately equal section moduli in bending, approximately equal lengths, approximately equal deflection amplitudes and opposite flexure directions; the angle between the longitudinal axis (L.sub.1) of a cleaning element and the normal direction of the transducer elastic member plane is 0° to 60°; the frequency of the alternating current in a drive coil is a fixed value equal to f.sub.0max−n, where n is a fixed value in the range of −0.3(f.sub.0max−f.sub.0min) to 0.85(f.sub.0max−f.sub.0min). Therefore, the appliance has a higher mechanical efficiency, a simple structure and a lower cost.