147results about "Motor control for high speed" patented technology

A control system for an AC motor determines a slope Ktl of a tangent TL at an operating point Pa corresponding to the current motor operating state and voltage phase (θ0) on a torque characteristic curve that is plotted according to a torque equation representing an output torque characteristic with respect to the motor operating state and the voltage phase of the rectangular wave voltage. The control system further calculates a voltage phase change amount θff for use in feed-forward control, according to ΔTtl/Ktl obtained by dividing a torque compensation amount ΔTtl for feed-forward control by the slope Ktl.

A method of controlling an AC machine that includes a stator and a rotor. The method includes observing a stability parameter that is indicative of the stability of the AC machine and dependent on a current state of the AC machine; and controlling the AC machine based on the observed stability parameter so as to promote stable operation of the AC machine. The method may include controlling the AC machine to operate as a motor or as a generator. The AC machine may be a permanent magnet synchronous machine. A controller suitable for performing the method is also disclosed.

A brushless motor comprises: a stator 21 having armature coils 21a, 21b, and 21c; a rotor 22 which is rotated by a revolving magnetic field; and a switching element 30a, wherein the brushless motor has a rotation number control unit 33 which switches between low-speed and high-speed mode, wherein in the low-speed mode, the rotation number control unit 33 supplies current to the armature coils 21a, 21b, and 21c at predetermined energization timing and controls a duty ratio to control the rotation number of the rotor 22, and in the high-speed mode, the rotation number control unit 33 supplies current to the armature coils 21a, 21b, and 21c at energization timing advanced from the energization timing for the low-speed mode, thereby performing field weakening control of weakening the revolving magnetic field from that of the low-speed mode to control the rotation number of the rotor 22.

Systems and methods for controlling a converter for powering a load are provided. According to one embodiment of the invention, a method for powering a load is provided. A power converter may be provided. At least one gating control signal having a switching pattern may be supplied to the power converter, wherein the switching pattern has a waveform with an effective switching frequency greater than 1 times the fundamental frequency of the switching pattern and less than 2 times the fundamental frequency of the switching pattern. At least one output power signal may be output to the load responsive at least in part to the at least one gating control signal supplied.

A control device for a driving apparatus configured with a rotary electric machine having a rotor with a permanent magnet and a stator having a coil. A field adjusting mechanism is configured to change a field flux supplied by the rotor, and an inverter is connected to the coil. A field command determining portion is configured to determine a field command value that serves as a target for the field flux that is adjusted by the field adjusting mechanism, based on at least a rotation speed of the rotor, with a field limiting value, that is set according to the rotation speed of the rotor within a range in which induced voltage that is induced in the coil will not exceed a voltage resistance of the inverter, as an upper limit.

The liquid supply apparatus includes: an inverter converting the frequency of an alternating-current power supply; a pump including an electric motor driven by the inverter; a control part; and the like. The control part includes a physical quantity detection part, a medium control part, and the like. The physical quantity detection part detects a physical quantity concerning the output of the inverter. On the basis of the physical quantity detected by the physical quantity detection part, the medium control part controls at least one of the flow rate and the pressure of the liquid supplied by the pump.

The invention relates to the technical field of automatic control, and discloses a weak magnetic control method and device for a running speed of an AC motor. The method comprises the steps of acquiring a direct-axis output voltage output from a torque inner ring; determining weak magnetic rotational speed compensation according to the direct-axis output voltage; and adjusting an actual given rotational speed according to the weak magnetic rotational speed compensation, and controlling the rotational speed of the AC motor according to the adjusted actual given rotational speed. According to the method disclosed by the embodiment of the invention, the weak magnetic rotational speed compensation is determined by acquiring the direct-axis voltage, the actual given rotational speed after the weak magnetic rotational speed compensation is adjusted according to the weak magnetic rotational speed compensation so as to further control the rotational speed of the AC motor; and therefore, during deep weak magnetic running of the motor, the rotational speed of the AC motor is controlled according to the actual given rotational speed after the weak magnetic rotational speed compensation, and meanwhile, the working stability of the motor is improved.

A LPF extracts DC component of a current detection value of an inverter input current. A subtracting section 4 calculates a difference between a current command value and the DC component of the current detection value. A current controller 5 produces two-phase PWM signals Sa and Sb complementary to each other, from the current difference. Further, an integrating circuit 7 integrates output terminal voltages Vu, Vv and Vw of the inverter to convert the output terminal voltages Vu, Vv and Vw into a magnetic-flux information Φu, Φv and Φw. A logic conversion section 8 converts the magnetic-flux information Φu, Φv and Φw into 120-degree conduction patterns S1′-S6′ to output the 120-degree conduction patterns S1′-S6′. Then, a logic circuit section 9 executes a logic synthesis between the PWM signals Sa and Sb and the 120-degree conduction patterns S1′-S6′ to output gate signals S1-S6.

A field weakening control system for use with an induction motor is disclosed. The field weakening control system has a sensing device configured to generate a signal indicative of a speed of the induction motor and a controller. The controller is configured to determine an initial voltage command based on the signal and determine an acceleration of the induction motor based on the signal. The controller is also configured to generate a desired voltage command based on at least one of the initial voltage command and the acceleration.