64 results about "Asynchronous machines" patented technology

The invention relates to a method for the controlled application of a stator-current target value (ISnom) and a torque target value (Mnom) for a polyphase machine (4) that is supplied by an electronic power converter. According to the invention: current components (ISdnom, ISqnom) in a co-ordinate system (d, q) with a fixed rotor flux or rotating magnetic pole are calculated in accordance with a torque target value and in asynchronous machines in accordance with a rotor-flux target value (ψRnom), a calculated rotor-flux actual value (ψ<SB>R< / SB>) or a rotating magnetic-pole flux; a stator-circuit frequency (ω<SB>S< / SB>) is determined; a terminal-flux target value (ψKnom) is calculated in accordance with the values (ISnom, ISqnom, ψ<SB>R< / SB>, ω<SB>S< / SB>) by means of the machine parameters (L, R<SB>S< / SB>), said terminal-flux target value being subsequently projected onto a flux-course curve, selected from stored, off-line optimised flux-course curves. This permits the state of the stator current (I<SB>S< / SB>) to be regulated in relation to the rotor flux (ψ<SB>R< / SB>) or rotating magnetic-pole flux by means of momentary values, facilitating a stationary and dynamic precise control of motor currents (I1,I2,I3) and thus the torques (M) of a polyphase machine (4).

The invention discloses an asynchronous electromechanical mixing spring-free antitheft alarming lock. A connection body of the asynchronous electromechanical mixing spring-free antitheft alarming lock is hidden in a hidden hole and is separated from a rear lock cylinder; an expansion sheet locks a front lock cylinder; the front lock cylinder and the rear lock cylinder are completely separated and asynchronously rotate to realize alarming; an electronic remote control device is mounted in a power supply circuit of an electromagnet in a hiding manner; electromechanical interlocking hiding, mechanical interlocking, connection hiding of the front lock cylinder and the rear lock cylinder and asynchronous alarming are integrated, so that a thieve cannot open an interlocking device and rotate the rear lock cylinder; even if an external expanded lock and the connection body part are damaged by a savage way, the thieve can only rotate the front lock cylinder, and the rear lock cylinder cannot be rotated; even if the thieve drills off the front cylinder lock and the rear cylinder lock with an electric hand drill and rotates a connection tongue with a tool such as a clamp, a rotating contact is not in contact with a fixed contact, so that the power supply circuit of the electromagnet cannot be conducted; furthermore, the electronic remote control device interrupts the power supply circuit of the electromagnet, so that the thieve cannot open an insurance lock lever, and a complete and thorough burglary prevention effect is achieved.

The invention provides an asynchronous machine stator flux estimation system based on a current model and a method. The system comprises a stator current sampling unit, a stator voltage sampling unit, a motor speed sampling unit, a coordinate conversion unit and a stator flux calculating unit, wherein the stator current sampling unit, the stator voltage sampling unit and the motor speed sampling unit are respectively used for sampling stator three-phase current, voltage and motor rotor speed of a three-phase motor; the coordinate conversion unit is used for converting the stator three-phase current and the stator three-phase voltage obtained through sampling into stator current and stator voltage of an axis alpha and an axis beta; and the stator flux calculating unit is used for calculating stator flux amplitude of the motor according to the stator current and the stator voltage of the axis alpha and the axis beta and the motor rotor speed. The invention also provides a corresponding method. The system obtains good stator flux estimation effect by decoupling cross coupling items estimated through stator flux of the axis alpha and the axis beta in a static coordinate system.