38results about How to "Fast demagnetization" patented technology

The invention relates to a control circuit (2) for an electromagnetic drive. Said circuit contains first and second electronic switching elements (16 to 22), which in conjunction with a timing element (12) subject the drive coil (4) to a corresponding direct current in the starting phase or in the maintenance phase. A starting current (Ua) and a maintenance current (Ub) are provided by means of a current source (14) that is controlled by the timing element (12) and a direct current converter (10) with downward control.

The present invention discloses a switched reluctance motor four-level power circuit. A multi-phase independent boosted circuit portion is added on the basis of a traditional asymmetric power conversion circuit, the switched reluctance motor four-level power circuit comprises a public boost capacitor C2, switch tubes VTA1, VTB2 and VTC1, and diodes VDA1, VDB2 and VDC1. Through control of the switching of switch tubes in the power topology, each phase winding of a switch reluctance motor can be independently switched and operated in the four states of high speed excitation (+2), high speed demagnetization (-2), normal excitation (+1) and zero-pressure follow current (0) and can be not mutually disturbed. The independent switch of the four levels of each phase of switched reluctance motors is realized to make the overlapping operation (a conduction angle is larger than 120 degrees) of four-level power circuit work in each phase possible. A common capacitor replaces an independent capacitor of each-phase boosted circuit to effectively reduce the size of the power circuit, and the switched reluctance motor four-level power circuit has a high-robustness, high-reliability and compact structure, and has a large application prospect.

The invention relates to a quick response magnetic control electric reactor suitable for wind power field dynamic reactive compensation. The electric reactor is improved on the basis of a common magnetic control electric reactor in the prior art, and characterized in that a damping resistor R and an insulated gate bipolar translator (IGBT) connected with the damping resistor R in parallel are added. The damping resistor R is connected between the anode of a free-wheeling diode D1 and the tail end D11 of a first coil L1, the IGBT is connected with the damping resistor R in parallel, and a gate electrode G is connected with an output end of an IGBT drive chip. The turn number between a first tap K11 and a second tap K12 is n1, a first tap ratio of the first coil L1 and a second coil L2 is delta1 which equals to n1/2N and equals to 1.5-3.0%, the turn number between a third tap K21 and a fourth tap K22 is n2, and a second tap ratio of a third coil L3 and a fourth coil L4 is delta2 which equals to n2/2N and equals to 15-20%. The quick response magnetic control electric reactor has the advantages that by means of the damping resistor, fast demagnetization is realized, fast dynamic response of the magnetic control electric reactor is achieved, and the magnetic control electric reactor is simple, practical, high in reliability and low in cost.

This invention relates to a stable demagnetization method, which controls de-magnet according to the time sequence at the state when a generator is faulty: 1, at the time when an excitation regulator gets an excitation trip order from a set protection device, it starts up inversion de-magnet, 2, sending the trip order to an AC de-magnet switch and a DC de-magnet switch, 3, the excitation regulator executes the inversion to set a pulse control angle an inversion angle after delta-t1, 4, closing down the output pulse of the regulator with software or hardware after inverting for delta-t2, in which, delta-t1 is in the sphere greater than 0ms but smaller than or equal to 10ms, and delta-t2 is in the sphere greater than 4ms and smaller than or equal to 10ms, and the demagnetization methods of DC, AC, inverted and non-linear resistor energy-moving and closing pulse of thyristor are used inter-grate to realize stable demagnetization.

The invention discloses an output stage circuit of a high-side power switch, and belongs to the technical field of power integrated circuits. According to the invention, the high-side power tube is driven and controlled by the power tube grid driving module, the design of the output negative voltage clamping module is combined to realize inductive load rapid demagnetization and rising slope control, when the inductive load is demagnetized, a seventeenth diode, an eighteenth diode and a nineteenth diode in the output negative voltage clamping module are broken down. The first PMOS tube is opened to charge the grid electrode of the high-side power tube, so that the high-side power tube is rapidly opened, the voltage of the output node is prevented from further dropping, the voltage clampingof the output node is realized, and the layout area and the power consumption are reduced compared with the traditional inductive load rapid demagnetization scheme; meanwhile, the grid protection module and the current limiting module are designed, so that the output stage circuit can limit the maximum current of the high-side power tube while normally driving the high-side power tube to be switched on and off, and the high-side power tube is prevented from being burnt out.

The invention relates to a perforating robot with a power-off protection function. The perforating robot comprises a base, a supporting rod, a cross rod, a perforating mechanism and a protection mechanism. The cross rod is fixed above the base through the supporting rod, and the perforating mechanism is arranged on the cross rod. The protection mechanism comprises a box, a limiting assembly, a gasifying assembly and a suspending assembly. According to the perforating robot with the power-off protection function, a PLC controls the perforating mechanism to perforate holes, and rotation of a driving shaft is limited through the protection mechanism, so that the device is kept in a static state; a workpiece and an operator are protected, and safety is improved; compared with an existing protection mechanism, the protection mechanism can operate fast through quick demagnetization after the power failure of an electromagnet and the quick reaction of quick lime and water, and the flexibilityis high; and according to the mechanism, water vapor generated by the reaction of the quick lime and the water is adopted as a driving source, cost is low, and the practicality is improved.

The invention relates to an SRM direct instantaneous torque control method for DC bus voltage dynamic adjustment. According to the method, a DC-DC conversion circuit is added to the front end of a traditional asymmetric half-bridge power converter; an excitation path and a demagnetization path are decoupled, and a higher demagnetization voltage can be applied, so that the winding of the switched reluctance motor is demagnetized more quickly, corresponding buck-boost adjustment is performed on the DC bus voltage of the power converter according to different operating speeds of the switched reluctance motor, and the adjustment mode has the characteristic of opening angle optimization; the commutation rule of the switched reluctance motor is improved, and a commutation conduction region executes direct instantaneous torque control to reduce torque pulsation through higher demagnetization voltage under the condition of considering the optimal turn-on angle characteristic; in the full-rotating-speed operation range of the switched reluctance motor, a control strategy is controlled through direct instantaneous torque to reduce torque pulsation, and the control strategy does not need to be switched.

The invention relates to a magnetically-controlled reactor. The magnetically-controlled reactor comprises the following components of: a reactor winding which includes iron cores and coils of which the current magnitude is utilized to change the magnetic flux of the iron cores, wherein the coils are wound around the iron cores; a power supply circuit which is used for generating work current and outputting the current to the coils; a demagnetization circuit which is connected between the output end of the power supply circuit and the coils of the reactor winding and is used for disconnecting the current that is outputted to the coils by the power supply circuit so as to fast decrease the current of the coils and accelerate the demagnetization of the iron cores. With the magnetically-controlled reactor adopted, fast demagnetization can be realized, and tap voltage and an additional excitation winding are not needed to be increased.

The invention relates to a control circuit for a synchronous machine (1) of a dental handpiece, comprising a voltage supply (2) and a clamping circuit (7) connected by switches (6). The invention also relates to a method for determining an angular position of a rotor of a synchronous machine (1), wherein a power supply is switched off for a total period of time (T2), a clamping circuit (7) is connected for a time interval (T1), whereupon an electromotive force is measured, and the angular position is determined from the electromotive force.

The invention relates to a power unit for an electronic jacquard needle selecting mechanism. The power unit comprises an iron core, a concentrating flux sleeve, a movable armature and an elastic component, wherein the concentrating flux sleeve sleeves the iron core, and a coil is arranged between the concentrating flux sleeve and the iron core; the movable armature sleeves the iron core, the movable armature and the concentrating flux sleeve are attracted with each other when the coil is electrified; the elastic component is used for resetting the concentrating flux sleeve and the movable armature. Compared with the prior art, the power unit for the electronic jacquard needle selecting mechanism has the following beneficial effects that the structure is simple, a relatively large needle number on a unit area can be obtained, and the dense arrangement can be achieved, so that the unit cost is reduced; furthermore, the integration level can be improved.