539 results about "Chopper" patented technology

An energy supply system has a number of DC choppers for converting the input voltages applied in each case into output voltages, and a number of energy storages for providing the input voltages, an energy storage being assigned to each DC chopper. An output voltage of at least one of the number of DC choppers is settable as a function of a setpoint input in order to expose the energy storage assigned to the at least one DC chopper to a load individually.

A relatively low frequency chopping operation is applied to a delta-sigma ADC to reduce DC offsets resulting from non-ideal component operation. Sequential chopping takes place outside a closed loop and may include an inverted polarity feedback for a part of the chopping period. Nested chopping involves chopping within the closed loop, and may include an inverted polarity feedback and a time shift. The feedback compensation for sequential and nested chopping permits the correct polarity feedback to be provided at the desired time in conjunction with sampling and quantization events. Integrating capacitor(s) may be swapped in relative polarity during nested chopping to preserve residual conversion information for the desired polarity. The ADC operation is non-temperature dependent and avoids modification to the useful signal, resulting in higher accuracy.

Choppers are provided respectively in the output stages of two diode bridges, and their output sides are connected in parallel to a smoothing capacitor. By controlling the operations of the two choppers, the currents which are allowed to be inputted to the diode bridges are made triangular waves of mutually opposite phases, or middle-phase waveforms of three phases.

A Hall electromotive force signal detection circuit combines offset cancellation means by a spinning current method of a Hall element with a continuous-time signal processing circuit. A first Hall element includes first to fourth terminals, and generates a Hall electromotive force signal voltage Vhall1. A third Hall element generates an other Hall electromotive force signal voltage Vhall3. A first switching circuit selects a terminal position for applying a drive current from the four terminals of the first Hall element. A third switching circuit selects a terminal position for applying a drive current from the four terminals of the third Hall element, which is different from the terminal position selected by the first switching circuit. A chopper clock generation circuit supplies a chopper clock signal φ1, φ2 having two different phases to the switching circuit, and also supplies the chopper clock signal φ1, φ2 to the switching circuit.

A method and circuit for dimmable light emitting diode (LED) applications are provided. The circuit includes digital processing circuitry and a DC output chopper. The digital processing circuitry produces a pulse width modulated (PWM) signal in response to one or more of voltage, frequency, dimmer type and phase angle requirements determined from a voltage and a phase position of a received inputsignal. The DC output chopper is coupled to the digital processing circuitry and operates in response to the PWM signal to generate a chopped DC output duty cycle voltage signal from a DC output signal derived from the input signal to provide linear dimming for a LED load.

A DC chopper comprising a control unit and a power circuit and a DC chopping method for a DFIG (doubly fed induction generator) system are provided. The input terminal of the control unit is coupled to a DC capacitor of a converter to detect a DC voltage. The power circuit includes input terminals, an overvoltage protection module, a rectifier module and output terminals. The overvoltage protection module comprises at least one discharge unit formed from a discharge resistor and a switch element, and the rectifier module is coupled in parallel to the overvoltage protection module. When a grid voltage drops, the control unit outputs a corresponding control signal to drive the switch element to be ON or OFF, and the output terminal of the power circuit absorbs a portion of rotor inrush current, so as to impose over-current protection.

The utility model provides a wind farm super capacitor energy storage type unified power quality conditioner which comprises a compensation transformer, a series connection compensator, a parallel connection compensator, a current limiting circuit, a super capacitor group, a bidirectional DC / DC chopper circuit, a signal acquisition conditioning circuit, a control circuit and a driving circuit. The conditioner has two control modes which are a power regulating mode and a low voltage ride through mode. In the power regulating mode, the wind power unit assembly output power quality can be improved, in the low voltage ride through mode, namely in a fault condition, the blower outlet voltage can be maintained and is not reduced, and the current influence on a blower system is avoided until the voltage is recovered and the low voltage ride through is realized. Electric energy generated by the blower in a fault stage can be stored in the super capacitor group, the energy is transmitted to the power grid after a power grid is recovered to a normal state, and the waste of the electric energy is avoided. The conditioner has versatility and can be applied to wind farms of various blower generations of a fixed speed induction generator (FSIG), a permanent magnet synchronous generator (PMSG) and a double-fed induction generator (DFIG).

The convertor includes three-phase filter capacitor (TFC), rectifier unit, and step up chopper unit, inverter unit at generator side as well as TFC and transformer at network side. Wind driven generator is connected to TFC, and TFC is connected to the rectifier unit. The rectifier unit is connected to the step up chopper unit, and the step up chopper unit is connected to the inverter unit. The inverter unit is connected to TFC, and the TFC is connected to transformer. The transformer is connected to power grid in power frequency. The invention reduces cost of Wind driven generation equipment greatly, and raises competitive power.

The invention relates to a vehicle auxiliary converter, which comprises a line side filtrating part (3), a direct-current conversion part (14) and an alternating-current conversion part (21). A diode (6) in the line side filtrating part is connected with a collecting electrode of a line side power switching tube (7), an emitting electrode of the line side power switching tube (7) is connected with an anode of a filtrating capacitor (9) to form the anode of a direct-current bus, both ends of a soft starting resistance (8) are respectively connected with the collecting electrode of the line side power switching tube (7) and the emitting electrode of the line side power switching tube (7). Power switching tubes of DC / DC wave choppers (10, 15) operate in a soft switching state. A DC / DC wave chopper (10) of the direct-current conversion part and the alternating-current conversion part is a zero-voltage soft switching resonant converter. The adoption of a contactless power switching tube instead of a contactor reduces the noise of the switch; as the power switching tube operates in the soft switching state, the consumption of the switch is reduced, and the adoption of a high-frequency transformer to insulate results in light weight.

The invention relates to a protection system of a doubly-fed induction machine, the system comprises a doubly-fed induction machine with a stator and a rotor, the stator of said doubly-fed induction machine is connected to a grid and the rotor of said doubly-fed induction machine is connected to the grid via a converter, said converter comprises a machine side converter, a DC-link and a line side converter. The system comprises additionally at least one crowbar, said crowbar is connected to the rotor, at least one DC-chopper provided in the DC-link, a converter controller and a separate protection device. The object of the present invention to provide a protection system and a protection method of a doubly-fed induction machine which can be easily used with high sampling rates and which provides a good protection for the doubly fed induction machine is resolved in that the DC-chopper and the crowbar are controlled with the separate protection device.

A relatively low frequency chopping operation is applied to a delta-sigma ADC to reduce DC offsets resulting from non-ideal component operation. Sequential chopping takes place outside a closed loop and may include an inverted polarity feedback for a part of the chopping period. Nested chopping involves chopping within the closed loop, and may include an inverted polarity feedback and a time shift. The feedback compensation for sequential and nested chopping permits the correct polarity feedback to be provided at the desired time in conjunction with sampling and quantization events. Integrating capacitor(s) may be swapped in relative polarity during nested chopping to preserve residual conversion information for the desired polarity. The ADC operation is non-temperature dependent and avoids modification to the useful signal, resulting in higher accuracy.

A braking torque closed-loop control system and method for a switch reluctance motor. The closed-loop control system comprises a torque regulator, a mode selector, a current regulator, an angle optimization controller and a torque estimator. On the basis of the rotating speed of the motor, the mode selector implements a phase current soft chopper control in a low rotating speed region and an angle position control in a high rotating speed region. The current regulator performs soft chopper hysteretic current regulation. The angle optimization controller optimizes a turn-on angle and a turn-off angle of a power converter master switch to reduce torque pulsation and improve braking energy feedback efficiency. The torque estimator conducts an on-line estimation of an actual braking torque estimated value of the motor based on an actual phase voltage and current of the motor to achieve braking torque signal feedback.

A chopper-direct-conversion (CDC) radio receiver includes a phase-alternating mixer receiving an antenna input signal and at least one local oscillator signal and generating a double sideband signal in a single mixing step. The phase-alternating mixer may be implemented by two parallel mixers each mixing the input signal with one of two local oscillator signals and an adder receiving and summing outputs from the two parallel mixers, by a track-and-hold circuit sampling the input signal based upon the local oscillator signal, or by a window averaging circuit averaging the input signal across a period of the local oscillator signal. The CDC architecture is suitable for fabrication on a single chip and offers solutions to virtually all problems found in conventional direct-conversion receivers.

In the fast chopper circuit and method of the switched reluctance motor drive system, the current sampling circuit (4) collects the instantaneous value of the phase winding current of the motor, and transmits it to the microprocessor (1) in real time, and the microprocessor (1) judges the motor Whether the instantaneous value of the phase winding current needs chopping, and output the pulse width modulation signal and the chopping signal according to the judgment result. Control signal to control its upper switch tube. After the microprocessor (1) makes an internal judgment, it outputs the pulse width modulation signal and the chopping signal to the two-input AND gate (2) through the pulse width modulation module (11) and the input and output module (12): if the current is higher than the chopping signal If the current is lower than the lower limit of chopping, the chopping signal is set high to turn on the upper tube of the power converter (3). Control signal; realize fast chopping control of the power converter.

The invention relates to an integrated high-power chopper, comprising a plurality of high-power choppers mutually connected in parallel. The high-power choppers are of an easily dismounted whole box-type part structure comprising a plurality of high-power IGBT (Insulated Gate Bipolar Transistor) modules, filter capacitors and a cooling device, wherein the grids of the high-power IGBT modules are connected to a PWM (Pulse Width Modulation) control circuit board; the high-power IGBT modules, the cooling device and the filter capacitors are intensively and fixedly arranged in a first box; the PWM control circuit board is arranged in a second box; the first box is provided with a plurality of openings so that the electrode conductors of the collectors of the IGBT modules and the electrode conductors of the filter capacitors can be exposed out of the first box; and the pipeline interface of the cooling device is exposed out of the first box through the openings. The invention also provides a high-frequency switching power supply comprising an uncontrolled rectifier and a filter circuit connected with the uncontrolled rectifier, a plurality of integrated high-power choppers are mutually connected in parallel and / or in series; and the cooling device of the integrated high-power choppers is connected with a cooling medium conveying pipeline.

The invention provides a two-stage inversion type micro-arc oxidation power supply, comprising a main circuit, a control system and a human-computer interaction device, wherein, the main circuit comprises a power supply switch, an input rectifying and filtering circuit, a power inverter circuit, a high frequency transformer, an output rectifying and filtering circuit and a chopper inverter circuit. The control system comprises a control transformer and a control circuit. The human-computer interaction device comprises a keyboard and a display. The control transformer and the input rectifying and filtering circuit are respectively connected with a power frequency AC network by the power supply switch. The chopper inverter circuit is connected with a load. The control circuit is respectively connected with the power inverter circuit, the chopper inverter circuit, the keyboard, the display and the output end of the output rectifying and filtering circuit. The two-stage inversion type micro-arc oxidation power supply is characterized by high control precision, rapid response speed and multiple outputs. Furthermore, the technique stability is good and the intelligent monitoring is adopted, therefore, high efficiency, high frequency and intelligence can be realized.

A method of controlling a direct current (“DC”) chopper controller having a switch and a storage choke in which the choke has a current dependent on the switching of the switch on and off includes the following. A current variable derived from one of the time averaged value of the current of the choke and the peak value of the current of the choke is determined. A switching frequency for synchronizing the turning on and off the switch is calculated as a function of the current variable and on whether the current variable exceeds a current threshold. The switching frequency is determined to be a predetermined low frequency if the switching frequency is lower than the low frequency and is determined to be a predetermined high frequency if the switching frequency is greater than the high frequency. The switch is switched on and off in accordance with the switching frequency.

The invention discloses a bidirectional vehicle-mounted charger circuit integrated with a DC / DC converter, which comprises a bidirectional AC / DC circuit and a bidirectional DC / DC conversion circuit; the bidirectional DC / DC conversion circuit comprises a transformer, two H-bridge switching circuits and a full-wave rectification circuit; the first H-bridge switching circuit is connected with the first winding through the first resonance circuit, and the second H-bridge switching circuit is connected with the second winding through the second resonance circuit; first ends of two half-wave rectification branches of the full-wave rectification circuit are respectively connected with two ends of the third winding, second ends of the two half-wave rectification branches are connected with a firstend of an output end of the full-wave rectification circuit, and a center tap of the third winding is connected with a second end of the output end of the full-wave rectification circuit. The half-wave rectification branch comprises a rectifier tube and a chopper tube, the rectifier tube and the chopper tube are connected in series in a common-source mode, the rectifier tube and the chopper tubeof the half-wave rectification branch are switched on at the same time, the chopper tube and a switching tube at the dotted terminal of the input side winding are switched off at the same time, and the rectifier tube is switched off in a delayed mode relative to the chopper tube. According to the invention, the voltage stress of the half-wave rectification branch switching tube can be reduced, andthe breakdown risk is reduced.

A chopper-stabilized amplifier includes a main signal path having first and second chopping circuits at the inputs and outputs of a transconductance amplifier, and an auto-correction feedback loop. The feedback loop includes a transconductance amplifier connected to amplify the chopped output from the main signal path, a third chopping circuit which chops the amplified output, a filter which filters the chopped output to substantially reduce any offset voltage-induced AC component present in the signal being filtered, and a transconductance amplifier which receives the filtered output and produces an output which is coupled back into the main signal path. When properly arranged, the auto-correction feedback loop operates to suppress transconductance amplifier-related offset voltages and offset voltage-induced ripple that might otherwise be present in the amplifier's output.

The invention concerns an installation constituting a railway propulsion chain, characterized in that it comprises, sequentially arranged, in the power electrical circuit, between a power transformer powered by a catenary and an electric motor of said vehicle, said catenary being capable of supplying a plurality of voltages, alternating or direct, said electrical circuit comprising a plurality of contact switches for selecting a given catenary voltage, at least one of the following elements: a controlled rectifier bridge (A1, A2), preferably a single-phase bridge with forced switching; a substantially reactive input filter (A3), preferably comprising at least a capacitance and / or at least an induction coil; a braking chopper capable of including also a clipping function (B); a multiphase and multilevel static converter (C1, C2, C3), preferably three-phase; electronic components, preferably IGBT power semiconductors for each element, each element belonging to at least an elementary power arm of the modular circuit diagram.

The invention relates to a wide-input voltage range arc power-supply device. A wide-range commercial power voltage is divided into a low-voltage module voltage, a medium-voltage module voltage and a high-voltage module voltage after rectified, filtered and stabilized, the low-voltage module voltage is boosted and the high-voltage module voltage is bucked as well as the medium-voltage module voltage is directly connected by a booster chopper circuit and a cascade voltage-reducing chopper, and then the low-voltage module voltage, the medium-voltage module voltage and the high-voltage module voltage are inverted by one group of inverters for obtaining the single voltage value with the required frequency so as to be used by an inversion type electric welder, and the single voltage value can be connected with the single-phase / three-phase power supply voltage, thus the flexibility is stronger.

The invention relates to a low-common-mode-noise grid-connected inverter circuit and a reactive power control method. The low-common-mode-noise grid-connected inverter circuit comprises an enhanced voltage-reducing chopper circuit and a silicon controlled rectifier power frequency phase-changing circuit, wherein the enhanced voltage-reducing chopper circuit comprises a power switch tube modulated through sinusoidal pulse width modulation (SPWM), a double-follow-current diode, a power-factor control power switch tube, an inductor and a capacitor. The direct current electric energy is converted into sine semiwaves by adjusting the duty ratio of high-frequency switch tubes in the enhanced voltage-reducing chopper circuit. The power-factor can be adjusted by adjusting a conducting mode of the power-factor control power switch tube. The phase-changing circuit consisting of four low-frequency silicon controlled rectifiers performs phase changing on the direct current sine semiwave to obtain full sine waves and finishes inversion from the direct current to the sine alternating current. Compared with conventional full-bridge grid-connected inverter circuits, the low-common-mode-noise grid-connected inverter circuit is simple in structure, strong in overcurrent-resisting capacity, high in stability and inversion efficiency and low in cost, and the number of the high-frequency switch tubes is approximately decreased by one half. Due to the fact that a whole inversion loop is fully symmetrical in the switching and phase-changing process, the common-mode voltage produced by inverted alternating-current output is constant, the common-mode current is restrained, and electro-magnetic interference (EMI) is reduced.

The invention discloses an AC chopper-full bridge rectification AC-DC converter in the technical field of power electronic conversion, comprising: a step-down circuit and a rectifier circuit or an impedance conversion circuit connected in series in sequence, and the step-down circuit is converted by an AC chopper The high-voltage power-frequency AC voltage is transformed into a high-voltage and high-frequency pulsed AC voltage, and the low-voltage and high-frequency pulsed AC voltage is obtained through step-down transformer step-down; the rectification circuit or impedance transformation circuit rectifies the output low-voltage and high-frequency pulsed AC voltage to obtain a stable The DC output and linear input impedance are reflected to the high-voltage AC grid to obtain linear input impedance and unit input power factor. The invention realizes the conversion of high-voltage AC voltage to low-voltage DC voltage through a step-down circuit and a rectifier circuit, and has the advantages of fewer power devices, simple overall structure and more perfect overall performance.

A cascaded H-bridge (CHB) inverter for higher rated power conditioning systems which operates at medium voltages while providing high power quality and low dv / dt. By incorporating battery energy storage, the power conditioning system operates at night to provide power to a load or grid and stabilizes the system during sudden changes in climatic conditions. Various energy storage system (ESS) configurations such as AC side coupled ESS, dual active bridge based ESS, and chopper based ESS configurations for cascaded H-bridge inverters are described. A comparison of these configurations on the basis of cost, control complexity, controller hardware requirements was performed and the advantages of chopper based ESS configurations over other ESS configurations was demonstrated. A control algorithm for the chopper based configurations was developed to operate the system in standalone and grid-connected modes of operation.

The invention relates to a three-phase alternating-current chopper which is connected between a three-phase alternating current voltage source and a load and can provide a voltage the phase of which is the same to the input voltage phase and amplitude of which is changed to the load. The three-phase alternating-current chopper comprises an input filter circuit, a semiconductor switch circuit, an output filter circuit, a voltage polarity detector and a switch control logic circuit, wherein the input end of the voltage polarity detector is connected with the three-phase alternating-current power supply and is used for detecting the polarity of the line voltage of the three-phase alternating-current power supply and sending a detected line voltage polarity signal to the switch control logic circuit; and the switch control logic unit controls the switching of semiconductor switch circuit states according to the voltage polarity signal sent by the voltage polarity detector. When the copper is converted between an active mode and a follow current mode by using the switch control method, the current is in a loop in a loaded line, so that damage of the semiconductor switch is not generated for no peak voltages are generated on the load and line inducer due to an overlarge current change rate.

A method and arrangement for determination of the sharpness of chopping blades of a field chopper during chopping includes the steps of measuring, at least at two points in time, a characteristic parameter of the operating oscillation of a component of the chopping unit. Each such measurement obtains the oscillation fractions of at least two frequency bands of the measured signal or its peak, with the ratio between the two measurements being evaluated to generate a signal, when a certain deviation is determined between the initial measurement and the current measurement, which is indicative of the need to sharpen the chopping blades and the counterblade. The sharpening process can then be automatically initiated.

The invention provides a dynamic two-way wireless charging system for an electric vehicle. The dynamic two-way wireless charging system includes a transmitting device and a receiving device, the transmitting device includes an alternating current power supply, a power supply PFC circuit, a bi-directional DC / DC circuit, a first bi-directional AC / DC circuit, a first resonant compensation module, a first coil and a first control module; the receiving device includes a second coil, a second resonant compensation module, a second bi-directional AC / DC circuit, a storage battery pack, a third bi-directional AC / DC circuit, an alternating current dynamo, a super-capacitor and a second control module; and when the power PFC circuit works in a rectification mode, the bi-directional DC / DC circuit works in a buck chopper mode, the first bi-directional AC / DC circuit works in an inversion mode, the second bi-directional AC / DC circuit works in the rectification mode and the third bi-directional AC / DCcircuit works in the rectification or inversion mode, the electric vehicle is in a dynamic charging mode, and otherwise, the electric vehicle is in a feed mode. According to the dynamic two-way wireless charging system for the electric vehicle, the functions of dynamic charging of the electric vehicle and dynamic feed to a power grid are achieved at the same time, stable operation of the power grid is maintained, and energy waste is reduced.