34results about How to "Reduce current fluctuations" patented technology

The invention proposes a static var compensator (SVC) and DC ice-melting device and a realization method thereof. Primary equipment comprises a thyristor rectifier, a reactor, an AC/DC filter, a disconnecting switch, a zinc oxide arrester and the like, wherein the thyristor rectifier is also taken as the thyristor controlled reactor (TCR) valve bank; the reactor is the phase-change smoothing TCR;the thyristor rectifier and the reactor are designed into the detachable structures, therefore, the thyristor rectifier and the reactor are detached and reassembled to form different topological structures by arranging the disconnecting switch between the detachable structures and operating the line disconnecting switch, so as to realize the switchover between the DC ice-melting function and the SVC function and solve the problem of the heavy-current high-voltage and high-capacity DC ice-melting device and the problem of system reactive power compensation.

The invention discloses an asynchronous motor model prediction direct torque control method, and relates to the technical field of motor control. Two control methods are improved through the mode of partition prediction and table lookup on the basis of comparative research of the performance of two control methods. According to the method, the system performance can be further improved, and the transient and steady-state torque ripple, stator flux linkage and current fluctuation of the motor can be significantly reduced. The simulation result proves that the torque, the flux linkage and the current fluctuation of the conventional DTC can be effectively reduced by the novel DTC strategy, the advantages of rapid response and simple control of the conventional DTC can be maintained and the control performance of the conventional DTC can be improved; meanwhile, vector selection is performed through combination of the partition table so that the dependence of finite model prediction controlon the model parameter accuracy can be reduced, and online computation of finite model prediction control can also be greatly reduced.

A system for MR signal excitation and reception and method which uses a non-resonant device or transmission line to perform MR imaging and spectroscopy. The system with non-resonant device is advantageous to parallel imaging due to the improved decoupling performance. Because the non-resonant RF coil is not generally sensitive to frequency, a MR system with the non-resonant RF coil is capable of multinuclear MR operation at varied magnetic field strength. The system comprises a non-resonant RF coil for connecting to an MR system, the conductor being configured to have a characteristic impedance matched to the MR system. The RF coil is configured to produce electromagnetic fields of differing strengths based on the constant characteristic impedance maintained in the system for exciting and receiving MR signals.

Provided are a switched reluctance generator power converter and a regulation method. The power converter includes a main circuit and an excitation circuit, the control loop of each phase winding of the main circuit is composed of two switch tubes and a diode, the two switch tubes are closed when in the excitation process, and the switch tube at the lower end is disconnected during the generation,the switch tube at the upper end and the diode generate power in a flow current manner, the power generation voltage is output to obtain a large gain; the excitation circuit is of a structure and a mode that two isolation type voltage transformation circuits work alternatively after the two isolation type voltage transformation circuits are connected in parallel, in addition to the decoupling ofthe adjustable output excitation voltage from the generation voltage, the two switch tubes are switched on and off alternately, the current output after parallel connection is more stable and the torque ripple inhibition is facilitated, and the whole system is more suitable for being used by a power generation terminal of a local-area direct-current microgrid with medium and small power.

The invention discloses a method for preparing a resistive random access memory. The method comprises the following steps of providing a substrate; depositing a first metal layer on the upper surfaceof the substrate; depositing a resistive functional layer on the upper surface of the first metal layer; depositing a material layer having a low mobility on the upper surface of the resistive functional layer; preparing one or more via holes on the material layer having the low mobility; and depositing a second metal layer on the upper surface of the material layer having the low mobility. According to the method for preparing a resistive random access memory provided by the invention, the resistive random access memory prepared can control the size of conductive filaments. Since the growth orientation, number and size of the conductive filaments can be controlled, the randomness of the growth of the conductive filaments can be reduced and the current fluctuation of the resistive random access memory can be reduced, thereby reducing the parameter fluctuation of the resistive random access memory and improving the reliability of the resistive random access memory.

A stanchion system, includes a stanchion post and an attachment system for attachment to a flange which includes a first edge and a second edge. The attachment system includes a crossbar including an extending section and an abutment member on a first end thereof to abut the first edge of the flange; a base including a passage through which the extending section of the crossbar is movable and a seating for the stanchion post; and a connector including a first section and a second section. The second section of the connector is attachable to the extending section of the crossbar at one of a plurality of incremental positions. The first section of the connector is movable relative to the second section to adjust the position of the first section relative to the abutment member of the crossbar. In several embodiments, the first section is movable relative to the second section to abut the base on a side of the base opposite the side upon which the flange is positioned to adjust the position of the first section relative to the abutment member.

The invention discloses an undisturbed switching control method of a magnetic suspension energy storage flywheel charging and discharging control system, which is used for energy storage flywheel charging and discharging switching control, guarantees that the voltage is stable and free of pulsation in the charging and discharging process, and achieves the switching time of 0. According to the method, voltage outer loop and current inner loop control is adopted in the charging process, the discharging process and the charging and discharging switching process, when the direct-current bus voltage Udc is greater than a voltage stabilization value Vref set by a flywheel, the output of a voltage outer loop proportional integral link is positive, a three-phase bridge works in an inversion state,the flywheel accelerates charging, and conversion from electric energy to kinetic energy is achieved; when the direct-current bus voltage Udc is less than the flywheel voltage stabilization value Vref due to mains supply power failure or power insufficiency, the output of the voltage outer loop proportional integral link is negative, the three-phase bridge works in a controllable rectification state, and conversion from mechanical energy to electric energy is achieved. Because the whole process of the voltage outer loop is controlled in real time, the method essentially solves the problem ofcurrent and voltage fluctuation during charging and discharging switching of the energy storage flywheel, and improves the dynamic response speed and power supply quality of the flywheel battery.

The invention relates to a method for performing an array built-in self-test (ABIST) on an electronic circuit (100), the electronic circuit (100) comprising a memory (110) with at least two memory arrays (111-115) and at least two array built-in self-test engines (116-120), wherein each automatic built-in self-test engine (116-120) is associated with a different memory array (111-115) and wherein each array built-in self-test engine (116-120) is associated with a programmable delay unit (DU1-DU5), the method comprising the following steps:

determine at least one delay value (dn), the delay value (dn) corresponding to an array built-in self-test engine (116-120) and the delay value (dn) depending on the execution time (tdn) for testing the memory array (111-115) associated with the array built-in self-test engine (116-120);

provide the at least one delay value (dn) to the programmable delay unit (DU1-DU5); and delay the start of the array built-in self-test engine (116-120) depending on the respective delay value (dn).

The invention discloses a permanent magnet synchronous motor angle identification system and method. The system comprises: a phase-locked loop used for calculating an aperiodic DC component of an angle; a self-adaptive angle compensator used for combining the non-periodic direct current component of the angle with the error angle to calculate and obtain an estimated electrical angle; a differentiator used for differentiating the estimated electrical angle to obtain an estimated rotating speed; an adaptive controller used for obtaining a trigonometric function coefficient of the initial periodic angle so as to obtain an estimated periodic angle; and an integrator used for obtaining a target trigonometric function coefficient so as to obtain a target periodic angle. According to the self-adaptive control principle, the trigonometric function coefficient of the periodic angle is identified in real time, and then the periodic angle is formed through combination; and in the control process, the periodic angle and the angle obtained through calculation of the phase-locked loop are added, the observation angle precision of position sensorless control is improved, the control performance can be greatly improved, and speed and current fluctuation is reduced.

The invention discloses a control method for a multi-branch PTC heater. The multi-branch PTC heater comprises a plurality of PCT heating devices which are connected in parallel, and employs a drive controller which is electrically connected between a DC bus power supply and each PCT heating device to achieve the drive control of each PCT heating device. The drive controller comprises an MCU main control module and a plurality of drive circuits applied to the PCT heating devices respectively. The MCU main control module sends PWM duty ratio signals with the same frequency to the drive circuitsrespectively. The PWM duty ratio signals of the at least two drive circuits have a phase difference which is not equal to 0, improving the average degree of input power of the multi-branch PTC heaterin a single signal period. According to the invention, impact on the PTC heater and related components in the working process of the multi-branch PTC heater can be reduced, and finally, the stability,safety and reliability of the multi-branch PTC heater are improved; and the service life of the multi-branch PTC heater in practical application is guaranteed.

The invention relates to a green energy saving electric arc furnace controlling device, which can lead that the electric arc furnace has little influence on a power system, can increase production efficiency of the electric arc furnace and reduces unit consumption. The device has the technical proposal that the green energy saving electric arc furnace controlling device is characterized in that the device is also provided with a switch transformer, a main control unit circuit and a phase-control trigger element circuit; the beginning terminal of the primary side winding of the switch transformer is connected with a power supply by a breaker while the end is connected with the corresponding tap of an arc furnace transformer; two ends of the secondary side winding of the switch transformer are connected with thyristors which are positive and negative in parallel connection. The main control unit circuit and the signal input end of the phase-control trigger element circuit are connected with a current transformator, a pressure transformator. The given input end of the phase-control triggers element circuit is connected with the output end of the main control unit circuit output. The output end of the phase-control trigger element circuit is connected with the control end of the thyristors.

The invention discloses a sleep and air conditioner hybrid type intelligent adjusting system. The system comprises a power supply, an air conditioner body, a sleep control circuit, a signal receiver and an intelligent bracelet, wherein the air conditioner body, the sleep control circuit and the signal receiver are connected with the power supply, and the intelligent bracelet is connected with the signal receiver through a wireless network. The signal input end of the sleep control circuit is connected with the signal receiver, the power input end of the sleep control circuit is connected with the power supply, and the output end of the sleep control circuit is connected with the air conditioner body. An auxiliary signal receiving circuit is further arranged at the signal receiving end of the signal receiver. A filter and amplification circuit is connected in series between the signal receiver and the sleep control circuit. A power buffer circuit is further arranged at the output end of the power supply. According to the sleep and air conditioner hybrid type intelligent adjusting system provided by the invention, the indoor temperature can be automatically regulated and controlled according to the sleep depth of people, so that a more comfortable sleep environment is provided for people, and living quality of people is greatly improved; meanwhile, starting and stopping of an air conditioner can be adjusted according to ambient temperatures, and thus the product using effect is further improved.

The invention discloses a control method of a PTC heating device, and also relates to a control system applied by the control method, and a driving controller electrically connected between a direct current bus power supply and the PTC heating device is used for realizing driving control of the PTC heating device. The control method of the drive controller comprises temperature outer closed-loop control and current inner closed-loop control, wherein an output signal of the temperature outer closed-loop control is used as a target working current signal of the current inner closed-loop controlinput, and an output signal of the current inner closed-loop control is used as a PWM duty ratio signal for driving the PTC heating device; according to the invention, the working current of the PTC heating device is more stable than the working current of the PTC heating device adopting independent temperature closed-loop control in the prior art, the impact on the PTC heating device and relatedcomponents of a control system of the PTC heating device is obviously reduced, and the stability, safety and reliability of the PTC heating device are obviously improved.

The invention provides an electric signal acquisition system and method of a three-phase motor, and belongs to the technical field of electronics. The system comprises a three-phase upper half bridge arm, a three-phase lower half bridge arm, a micro-control unit and a first resistor; the first ends of the three-phase upper half bridge arm are connected with a first power supply, the control ends of the three-phase upper half bridge arm are respectively connected with the first control end, the second control end and the third control end of the micro-control unit, and the second ends of the three-phase upper half bridge arm and the first ends of the three-phase lower half bridge arm are respectively connected with three-phase binding posts of a three-phase motor; control ends of the three-phase lower half bridge arm are respectively connected with the fourth control end, the fifth control end and the sixth control end of the micro-control unit, and second ends of the three-phase lower half bridge arm are grounded through the first resistor; and each detection end of the micro-control unit is respectively connected with the first end of the three-phase lower half bridge arm and the three-phase binding post of the three-phase motor or the first end of the first resistor. According to the invention, the effects of reducing energy consumption, failure rate and cost can be achieved.

The embodiment of the invention provides a control method, a control device and a controller, which are used for controlling a motor. The control method comprises the steps: acquiring the position error mechanical frequency fluctuation quantity and the angular speed mechanical frequency fluctuation quantity; subtracting the position error from the mechanical frequency fluctuation quantity of the position error to obtain an updated position error; calculating a reckoning angular velocity according to the updated position error; superposing the angular velocity mechanical frequency fluctuation quantity to the reckoning angular velocity to obtain an updated angular velocity, and calculating the electrical angle position of the rotor according to the updated angular velocity; and carrying outthe motor control according to the updated angular speed and the electrical angle position of the rotor. According to the embodiment of the invention, feedforward compensation can be carried out on the estimated position error value of the motor, and the rotor position tracking capability is improved, so that the effect of improving the efficiency is achieved.

The invention discloses an alarm current-limiting type waste-heat power generation system based on a submerged-arc furnace. The alarm current-limiting type waste-heat power generation system based on the submerged-arc furnace comprises a waste heat boiler, an evaporation heating surface, a coal economizer, a steam pocket, a steam superheater, a steam turbine, a power generator, a flash evaporator and a condenser. A waste heat power generation control system is arranged inside the power generator 7. The waste heat power generation control system is composed of a transformer T1, a diode bridge rectifier U1 connected with a secondary side coil of the transformer T1 in series, a power circuit and a power amplification circuit connected between the positive output end and negative output end of the diode bridge rectifier U1 in series, a temperature alarm circuit connected with the positive output end of the diode bridge rectifier U1, and a current-limiting circuit connected to the power circuit in series. The two ends of a primary side coil of the transformer T1 form the input ends. The waste-heat power generation system capable of recovering waste heat can recover and process waste heat sufficiently, thereby increasing the utilization rate of energy and further relieving burdens of enterprises.

The invention discloses a three-terminal voltage-stabilized compressor constant-current driving system, which is characterized in that: it mainly consists of a driving chip U1, a resistor R4, a capacitor C4, a diode D2, a resistor R5, a constant-current source circuit, and a three-terminal voltage-stabilizing circuit And drive circuit composition. The present invention adopts the driving chip U1 combined with the peripheral constant current source circuit and the driving circuit, which can reduce the current fluctuation range of the driving system of the present invention, and provide a stable working current for the compressor, thereby prolonging the service life of the compressor for one and a half years The above are suitable for promotion and application.

The invention discloses a buffering type intelligent adjusting system for a sleep air conditioner power source. The buffering type intelligent adjusting system comprises the power source, an air conditioner body, a sleep control circuit, a signal receiver and an intelligent band, wherein the air conditioner body, the sleep control circuit and the signal receiver are connected with the power source, and the intelligent band is connected with the signal receiver through a wireless network. The signal input end of the sleep control circuit is connected with the signal receiver, the power input end of the sleep control circuit is connected with the power source, and the output end of the sleep control circuit is connected with the air conditioner body. The output end of the power source is further provided with a power source buffering circuit. According to the buffering type intelligent adjusting system for the sleep air conditioner power source, the indoor temperature can be automatically regulated and controlled according to the sleeping depth of people, people are made to have a more comfortable sleeping environment, and the living quality of people is greatly improved; and meanwhile the on-off states of an air conditioner can be adjusted according to the environment temperature, and the product using effect is further improved.

The invention discloses a compressor constant current drive system, which is characterized in that it is mainly composed of a drive chip U1, a resistor R4, a capacitor C4, a diode D2, a resistor R5, a constant current source circuit and a drive circuit. The present invention adopts the driving chip U1 combined with the peripheral constant current source circuit and the driving circuit, which can reduce the current fluctuation range of the driving system of the present invention, provide a stable working current for the compressor, and prolong the service life of the compressor by one and a half years. The above are suitable for promotion.