摘要:
A system and method are disclosed for turning off the voltage to a pump jack electric motor during predetermined periods of time to save energy. In the method, the motor's response to closed-loop control may be evaluated over several pump strokes. The periods of the pump stroke when it is feasible to turn off the motor may be identified. The consistency of the measurements over several strokes may be evaluated. The motor may be turned off during predetermined periods on subsequent pump strokes when each pump stroke shows sufficiently similar behavior to that predicted during the closed-loop control process. The system may return to the closed-loop control process after a predetermined period of time to adjust to any changes in the system.
摘要:
An electrical machine system including a permanent magnet assembly having a magnetic field and a plurality of conductive coils, the magnet assembly and coils arranged for relative rotation between the coils and magnetic field in the manner of an electrical generator or motor, the system further comprising a current injector electrically connected to said coils and arranged selectively to supply a current signal thereto, the current signal being asynchronous with the frequency of rotation between the permanent magnet assembly and coils so as to heat and thereby demagnetise one or more magnet within said permanent magnet assembly.
摘要:
In an induction motor group control system, magnetic energy recovery switches (3) are connected in series to an induction motor (2) directly driven by a commercial power supply, and a plurality of induction motor control devices (10) enabling voltage control and reactive power control of the induction motor 2 are employed to control generation of reactive power so as to maximize a power factor of the entire plurality of AC loads including the induction motor or compensate variations in voltage of an AC power supply (1).
摘要:
The invention relates to a switch arrangement of an electric motor drive (1). The electric motor drive comprises safety switches (3) determined by the safety of the drive, a controlled mechanical brake (4), a power supply circuit (5) of the brake control, a power converter (6), which power converter comprises a network rectifier (7) and a power rectifier (8) of the motor. The power rectifier of the motor is at least partly implemented with controlled semiconductor switches (9, 10) arranged into a bridge. The power converter comprises an intermediate circuit (11, 12) between the network rectifier and the power rectifier of the motor. The switch arrangement comprises normally-open switches (13, 14) in the intermediate circuit of the power converter (6).
摘要:
A device for filtering a carrier frequency of a PWM waveform. The device includes a low-pass filter for converting the PWM waveform into an analog signal. The device further includes a sampling analog-to-digital converter receiving the analog signal from the low-pass filter and the device also includes a controller for causing the non-integrating analog to digital converter to sample the PWM waveform at the pulse frequency rate thereby rejecting the carrier frequency. As already stated the PWM waveform includes a pulse which has a leading edge, a top portion, and a trailing edge. In one embodiment, the controller causes the A/D converter to sample during the top of the pulse. Preferably, the controller causes the A/D converter to sample at substantially the center of the pulse.
摘要:
A electric motor is disclosed in which torque ripple is reduced. The electric motor includes a single motor shaft. Rotors are disposed so as to be mutually offset in phase, and the rotors are secured to the motor shaft. Stators are arranged so as to individually correspond to the rotors, and the stators are disposed so as to be matched in phase. The phases of torque ripple generated in each motor unit, which is comprised of a combination of a single rotor and a single stator, are offset.
摘要:
An electric bike includes a wheel driving apparatus. The wheel driving apparatus includes an electric wheel drive motor which drives a wheel, a gap changer which changes a gap length in the wheel drive motor, and a motor control unit which controls the wheel drive motor and the gap changer. The motor control unit calculates a target gap length for the gap changing motor in the gap changer based on an accelerator opening-degree signal, a rotation speed, a q-axis electric-current command value, a power source voltage, and a voltage utilization rate. Then, a feedback control is provided to the gap changer based on a difference value between the target gap length and the actual gap-length. A good vehicle characteristic is obtained without being affected by individual variability or operating environment of the electric motor through efficient drive of the electric motor from a low-speed range through a high-speed range.
摘要:
A device of a motor with a rotation control means that decreases the fluctuation of its rotation period. The control is carried out based on the amplitude and the phase generated by amplitude-and-phase generating devices, detecting passage time of detected portions (13) in different zones. And a color image forming apparatus of tandem type with such motors.
摘要:
This application describes a motor designed to operate as a reluctance machine at low speeds and as an induction machine at high speeds. The drive waveform is composed of one or more harmonics to be used to match the reluctance pattern of the stator-rotor, causing the rotor to rotate due to the reluctance effect, and one or more other harmonics to induce current in the rotor, causing the rotor to rotate due to the induction effect and the subsequent interaction of the stator and rotor magnetic fields. The two effects are generally not applied simultaneously.
摘要:
A change in torque produced by a motor having two rotors is reduced when the motor operates in a low-velocity and low-torque operational state. The motor has a first rotor and a second rotor, each of which has a permanent magnet, and an output shaft capable of rotating integrally with the first rotor. The second rotor can relatively rotate with respect to the first rotor by a driving force from a phase difference changing driving device, and the phase difference between the rotors (rotor phase difference) can be changed by the relative rotation of the second rotor with respect to the first rotor. When the values of the torque and the rotational velocity of the motor lie within a predetermined region in the proximity of 0, the phase difference changing driving device adjusts the rotor phase difference to a predetermined phase difference for which the strength of a composite field of the permanent magnets is lower than a maximum strength.