261 results about "Chopper" patented technology

The invention discloses a fault ride-through test method for an offshore wind power flexible direct output system, and the method comprises the steps: building a fault equivalent circuit of the offshore wind power flexible direct output system, analyzing the operation characteristics of an AC power grid side under a low-voltage fault, and determining the incidence relation between the DC side excess energy and the power grid voltage drop; establishing a model representing each component in the fault equivalent circuit, wherein the components at least comprise a machine-side converter, a grid-side converter, a direct-current capacitor and an unloading resistor; when a low-voltage fault of an alternating-current power grid side is detected, executing the following cooperative control based on the model: synchronously starting unloading resistance control and reactive power support control, wherein an unloading resistor dissipates excess energy of a direct-current side through a direct-current chopper; the grid-side converter injects a capacitive reactive current which is deeply matched with the voltage drop of the power grid so as to improve the voltage of a grid-connected point; and if the direct-current voltage continuously exceeds the preset threshold value, starting power prompt drop control, and reducing the output power of the unit according to a gradient until the system recovers to be stable.

The present application provides a converter and a chopper transistor blocking control method therefor. According to the chopper transistor blocking control method, when switching transistors in a converter need to be blocked, switching transistors in a primary side circuit connected to a transformer of the converter are blocked, and switching transistors in a secondary side circuit are blocked when the current on a branch where a secondary side winding in the transformer is located is zero, or batch blocking of the switching transistors in the secondary side circuit is completed after the current on the branch where the secondary side winding is located recirculates to zero, thereby avoiding overvoltage damage to the switching transistors caused by the current on the branch where the secondary side winding is located recirculating by means of the junction capacitance of the switching transistors in the secondary side circuit.

The invention discloses a low-output-ripple ultralow-offset-voltage operational amplifier and a working method thereof. The low-output-ripple ultralow-offset-voltage operational amplifier comprises a first chopper circuit, a first-stage operational amplifier additionally provided with an offset voltage adjusting circuit, a second chopper circuit, a notch filter, a second-stage operational amplifier and a third-stage operational amplifier which are sequentially connected. The offset voltage adjusting circuit trims the input offset voltage of the first-stage operational amplifier to hundreds of microvolts and then outputs the offset voltage to the second chopper circuit; the first chopper circuit and the second chopper circuit are used for modulating the offset voltage of the first-stage operational amplifier to a chopping frequency, and then the ripple voltage at the chopping frequency is filtered by the notch filter; the first-stage operational amplifier is designed to be a high-gain amplifier so as to restrain input offset voltage errors caused by the second-stage operational amplifier and the third-stage operational amplifier. According to the invention, low output ripple voltage and ultralow input offset voltage can be realized only by using the wave trap with a small area.

The invention relates to the technical field of robot intelligent actuators, and discloses a magneto-rheological end effector accurate grasping system based on force feedback, which comprises a multi-curved-surface bionic fingertip formed by a magneto-rheological elastomer, and a three-dimensional distributed excitation coil array is embedded in the fingertip. The coil array is excited by a high-frequency chopping constant-current driving module to generate a space gradient magnetic field, and the magnetic field changes the shear modulus of the elastomer within millisecond-level time, so that the fingertip surface hardness jumps in real time along with a control instruction; and the force feedback closed-loop control unit comprises an ultrathin film strain sensing net attached to the inner curved surface of the fingertip. Through time-sharing switching of a negative pressure micropore adsorption layer and a magneto-rheological rigidity keeping mode, traditional adsorption and rigid clamping are changed into a pre-fixing and rigidity gradual change two-section type process, instantaneous force impact during adsorption release is eliminated, meanwhile, thin film wrinkling caused by continuous negative pressure is avoided, and it is ensured that an ultrathin and high-added-value workpiece is kept flat and traceless in the whole transfer process.

The invention provides a zero-voltage ride-through control method for a self-synchronizing voltage source doubly-fed wind turbine generator, which comprises the following steps that: when the self-synchronizing voltage source doubly-fed wind turbine generator is in a transient state, a grid-side converter adopts vector control, and a rotor-side converter adopts additional virtual impedance and annular current limiting; the transient overcurrent of the grid-side converter and the rotor-side converter can be effectively suppressed, so that the continuous operation capability of the wind turbine generator in the zero-voltage ride-through period can be maintained; meanwhile, by improving the transient capacity and the transient reactive current amplitude of the converter, the transient voltage supporting capacity of the wind turbine generator during the zero voltage ride-through period can be effectively provided; when the self-synchronizing voltage source doubly-fed wind turbine generator set is in a transient state, overvoltage of direct-current bus voltage is limited by a Chopper circuit, active-priority current amplitude limiting control is adopted by a grid-side converter, parameters of a current inner ring PI controller of a rotor-side converter are optimized, energy balance of a direct-current side can be achieved in the zero-voltage ride-through period, and stability of the direct-current bus voltage is maintained.

A gyro sensor circuit includes a gyro sensor generating a radio frequency (RF) sensing signal according to an angular movement of the gyro sensor, and an RF sensing path comprising a first chopper comprising a chopping switch, and configured to chop a tone signal at a chopping frequency to generate a chopped tone signal, an adder configured to insert the chopped tone signal to the RF sensing signal to produce a combined RF sensing and tone signal, and a first demodulator configured to mix the combined RF sensing and tone signal with a local oscillator (LO) signal to output a demodulated signal. The tone signal may be the LO signal. The gyro sensor circuit further comprises a sense base band path comprising a first analog-to-digital converter configured to sample the demodulated signal to output a digitized signal, and a first digital signal processor to extract various signals to be analyzed.

A locomotive has DC or AC traction motors, powered by a hydrogen fuel cell, and optionally other sources such as regenerative braking. The traction motors of the locomotive may be connected to a set of independent DC choppers or AC inverters, linked via a common DC bus, configured to regulate power from the one or more power sources. A manager module, among other functions, may receive inputs and signals to coordinate delivery of electricity from the sources to the motor. A method for retrofitting a legacy locomotive may include removing a generator and a control apparatus configured for diesel fuel, and installing a kit of apparatus configured to be powered by a hydrogen fuel cell. A railway system for use by locomotives powered by hydrogen has one or more hydrogen-generation stations deployed near a track of the railway system.

A DFIG wind power facility configured to be operated during grid faults is provided. The wind power facility includes a Doubly-Fed Induction Generator, a control system, an electric converter, a short-circuit controlled switch to selectively short-circuit the stator and a Stator Neutral Brake Chopper coupled to the stator. The DFIG includes a rotor and a stator, the stator including at least one three-phase winding. The electric converter includes a Machine Side Converter, a Grid Side Converter and a DC link connected therebetween. The SNBC includes a three-phase rectifier including three inputs, an impedance and an active high-frequency switch configured to vary the average value of the impedance by adjusting its duty cycle; each of the three inputs of the rectifier is connected to a phase of the at least one three-phase winding of the stator. Methods for operating a DFIG wind power facility during grid faults are also provided.

The invention provides a dual-mode parallel competition-dominated self-synchronizing voltage source wind turbine generator set and a control method thereof, and the wind turbine generator set comprises a wind power generation device which is composed of a wind turbine and a generator and is used for converting wind energy into electric energy; the alternating current / direct current conversion module consists of a power electronic converter and a chopper circuit and is used for realizing conversion between alternating current electric energy and direct current electric energy and realizing unloading when transient direct current voltage exceeds the limit; the self-synchronizing voltage source generation control module is composed of a dual-mode parallel competitive dominant control module, a modulation voltage control module and a synchronous phase angle control module and is used for autonomously establishing voltage, autonomously synchronizing a power grid and supporting transient frequency and voltage of the power grid; according to the direct current bus voltage and the power grid voltage, the self-synchronizing voltage source characteristics of the unit under multiple operation working conditions such as wind speed disturbance and power grid faults are maintained through state keeping and competitive leading of the two voltage source control modes. The invention is suitable for doubly-fed and full-power wind turbine generators, and comprises control, equipment and a system.

According to one embodiment, a chopper stabilized amplifier includes an input unit, a first chopper, a first amplifier, and a switch circuit. The input unit receives a differential input signal at a first input terminal and a second input terminal. The first chopper modulates the differential input signal based on a first control signal and an inverse signal of the first control signal. The first amplifier amplifies the signals with the modulated differential output from the first chopper. The switch circuit is provided between the input unit and the first chopper, and receives a second control signal and reduces input currents which flow in the first chopper when the first chopper performs a modulating operation, by using an operation with the second control signal.

A hardware (e.g., a process and / or circuitry) and / or software-based controller for septic system grinder or chopper units monitors load to the unit. As the unit encounters debris, electrical and mechanical load on the unit increases. In some cases, a signal to stop the unit from grinding / chopping (including but not limited to a signal based a waste-water level) is received while the unit is under the increased load. The controller may override the stop signal and continue sending power to the unit to clear the unit from debris causing increased load. The override may cease when it is determined that the debris has been cleared, such as when it is determined that the increased mechanical and / or electrical load on the unit has decreased or returned to a target load, allowing the unit to stop. The unit may include self-configuration functionality, determining thresholds for signaling override, target load, etc.

A signal processing device and a signal transceiver device are provided. The signal processing device includes a first amplifier, two first choppers, a second chopper, and a third chopper. The first amplifier is configured to generate a second signal from a first signal. The two first choppers are embedded between an input and an output of the first amplifier and are configured to perform a first frequency shift and a first frequency shift back, respectively. The second chopper is coupled to the input of the first amplifier and is configured to perform a second frequency shift. The third chopper is coupled to the output of the first amplifier and is configured to perform a second frequency shift back. The first frequency and the second frequency are different.

The utility model provides a multi-group chopper circuit parallel current sharing control system, and belongs to the technical field of current control. The multi-group chopper circuit parallel current sharing control system comprises chopper circuits, a switch selection module, an impedance detection module, a current control module and a main control module, the input end of the chopper circuit is connected with a DC power supply, the control end of the chopper circuit is connected with the main control module, the output end of the chopper circuit is connected with the input end of the switch selection module, the first output end of the switch selection module is connected with the input end of the current control module, and the second output end of the switch selection module is connected with the first end of the impedance detection module. The control end of the switch selection module is connected with the main control module; the output end of the current control module is used for connecting electric equipment, and the control end of the current control module is connected with the main control module; the second end of the impedance detection module is used for connecting electric equipment, and the control end of the impedance detection module is connected with the main control module. The stability of the power supply system can be improved.

The utility model provides a drive circuit with chopping and current limiting functions and a stage lamp, comprising an ILIMIT pin, an external pull-down resistor arranged on the ILIMIT pin; the output end of the H bridge is connected with a load; the first input end of the control logic circuit is connected with the ILIMIT pin, and the driving output end of the control logic circuit is connected with the H bridge; the control logic circuit comprises a calculation circuit, a current detection circuit, a comparison circuit and a chopper circuit, the ILIMIT pin serves as the input end of the calculation circuit, the input end of the comparison circuit is connected with the output end of the calculation circuit and the output end of the current detection circuit, and the input end of the chopper circuit is connected with the output end of the comparison circuit and the output end of the current detection circuit. The driving circuit provided by the utility model has a current chopping and current limiting function so as to prevent the output current of the H bridge from infinitely increasing, and surge current can be effectively limited without damaging a chip and a load during the starting or transient period of the load.

This invention discloses a liquid crystal filter-based lidar chopping device for atmospheric wind and temperature detection, comprising a digitally controlled voltage output module, a liquid crystal module, a light guide module, a timing control module, a polarization beam splitter module, a frequency discriminator module, a reference channel photodetector, a frequency discriminator channel photodetector, a photon counting and acquisition card, a computer, a pulsed laser, a telescope, and a collimation module. This invention also discloses a liquid crystal filter-based lidar chopping method for atmospheric wind and temperature detection. This invention solves the problem of atmospheric wind and temperature detection being limited by the dynamic range of the photodetector; the received signal attenuation amplitude can be adaptively adjusted in real time, better adapting to weather changes. Furthermore, although liquid crystal filtering introduces some signal loss, wind and temperature detection typically uses the ratio of the reference channel and frequency discriminator channel signals for inversion, so the final result is independent of the liquid crystal's transmittance, thus avoiding the negative impact of liquid crystal filtering.

This invention discloses a bandgap reference circuit structure, belonging to the field of integrated circuit design technology. The circuit structure includes a bandgap reference core circuit, a chopper-equipped operational amplifier (op-amp), a bandgap reference startup circuit, a temperature-to-absolute-temperature (PTAT) bias current source, and a current source startup circuit. By optimizing the bandgap reference core circuit architecture, combining chopper technology to eliminate the effects of offset voltage and device mismatch, and with the matching startup circuit and low-voltage-adaptive bias current source, the reference voltage is essentially independent of the op-amp input offset voltage, improving circuit symmetry performance and load dynamic response speed. Furthermore, in most common complementary metal-oxide-semiconductor (CMOS) processes, it only requires a power supply voltage of 2V or higher to operate stably, significantly improving the accuracy and stability of the reference voltage.

The invention provides an LED dimming constant-voltage power supply self-adaptive to load voltage and an overload protection method thereof, and the power supply comprises a main control circuit which is used for outputting a first reference voltage signal to enable a controlled voltage conversion circuit to be maximum voltage output, and outputting a PWM dimming signal to drive a first transistor through a chopper circuit. And outputting a switching signal to initiate voltage detection of the load; the self-detection circuit comprises a constant current source circuit and a first operational circuit, and the constant current source circuit is connected with a load to form a constant current power supply loop; the first operational circuit is used for measuring load voltage and outputting a voltage sampling signal to the main control circuit; the master control circuit outputs a second reference voltage signal to the controlled voltage conversion circuit according to the voltage sampling signal so that the controlled voltage conversion circuit can be adjusted to load voltage output. According to the invention, load voltage detection and load power supply voltage adjustment are realized by controlling the self-detection circuit, and overload protection under different output voltages is realized through the overload protection circuit.

The invention provides a power module voltage-sharing method of a flexible chopping type direct-current energy consumption device, specifically, the voltage-sharing method comprises the steps that voltage-sharing control is carried out on capacitors of power modules in an energy consumption valve of the direct-current energy consumption device in a capacitor voltage-sharing mode, and the energy consumption valve comprises N power modules which are connected in series. According to the invention, voltage-sharing control of the capacitors of the power modules in the energy consumption valve of the direct-current energy consumption device is effectively realized.

To suppress efficiency deterioration and discharge power stored in a capacitor without adding any element for power discharge.SOLUTION: A power source device includes a bidirectional step-up / step-down chopper including a first capacitor, a first switching element, a second switching element, an inductor, a third switching element, a fourth switching element, and a second capacitor, and a control unit that controls the bidirectional step-up / step-down chopper. To discharge power stored in the first capacitor, the control unit controls the third switching element to be turned off, controls the fourth switching element to be turned on, and controls the first switching element and the second switching element to be alternately turned on and off.SELECTED DRAWING: Figure 1

To provide an amplifier in which intermodulation distortion is reduced.SOLUTION: The auto-zero amplifier circuit 2122 includes a transconductance amplifier 211221 and sampling capacitors CM1 and CM2. A modulation chopper circuit 31,32 modulates an input signal and inputs the modulated signal to a mutual conductance amplifier 211,221. The auto-zero switch circuit 41 includes auto-zero switches S31 and S32, and the auto-zero switch circuit 42 includes auto-zero switches S33 and S34. One end of the dummy switch Sd1 is connected between the input-terminal INM and the connection point of the auto-zero switches S31 and S32. One end of the dummy switch Sd2 is connected between the input-terminal INP and the connection point of the auto-zero switches S33 and S34. A capacitor C4 is connected between the other ends of the dummy switches Sd1, Sd2 and a ground line.SELECTED DRAWING: Figure 1

This invention relates to the field of lighting control technology, specifically disclosing an environment-adaptive LED constant current energy-saving control method. The method includes: arranging a dielectric-photoelastic sensing array, a magnetostrictive-leakage flux detection coil, and a broadband impedance spectrum detection unit on the phosphor encapsulation layer, the inductor core, and the output bus, respectively; simultaneously acquiring three types of timing signals; extracting dielectric-magnetic-electric coupling degradation feature vectors; inputting the feature vectors into an energy-saving-lifetime co-optimization model; correcting the target luminous flux based on the dielectric relaxation offset; constructing a core loss-efficiency mapping surface to solve for the minimum energy consumption operating point; generating a constant current target value offset sequence and a PWM chopper phase-frequency co-transfer strategy; and simultaneously adjusting the duty cycle, switching frequency, and gate impedance through a feedforward-feedback composite adjustment network, and feeding back the current ripple spectrum and dielectric relaxation offset to update the feature vector weights. This invention achieves multi-physics field co-sensing and energy-saving-lifetime co-optimization.

The class AB amplifier device includes an input chopper switch circuit that performs a chopping operation in synchronization with a first and second chopper clock signal, and outputs first and second modulated signals obtained by modulating the first and second differential input signals to a first and second node; an input amplifier circuit that receives the first and second modulated signals via the first and second nodes, and outputs a differential amplified signal obtained by amplifying the first and second modulated signals; an output chopper switch circuit that receives the differential amplified signal, performs a chopping operation in synchronization with the first and second chopper clock signals, and modulates the differential amplified signal to output a demodulated signal demodulated to the frequency band of the first and second differential input signals; and an output amplifier circuit that outputs a first output signal obtained by amplifying the demodulated signal.

The invention provides a chopper unit and a wind generating set, and relates to the technical field of frequency converter equipment. Through the modular design, the structure is compact, two chopper outputs can be achieved through one structure, installation and maintenance are convenient, and the working efficiency is improved. The chopper unit and the wind generating set comprise a cabinet body, a radiator and a power module, wherein the cabinet body is provided with an accommodating cavity; the radiator is arranged in the accommodating cavity and is used for horizontally dividing the accommodating cavity into a first accommodating space and a second accommodating space; the power modules are arranged in the first accommodating space and the second accommodating space, each power module comprises a plurality of power elements, and the plurality of power elements are arranged in the vertical direction. The chopper unit and the wind generating set are used for expanding the power element.

The invention relates to the technical field of semiconductor packaging equipment, and discloses an automatic threading mechanism of a semiconductor packaging wire bonder, which comprises an operation table, a coiling assembly driven by a motor is arranged on one side of the top of the operation table, a wire bonding head is movably arranged on one side of the operation table, and one side of the wire bonding head is fixedly connected with a chopper through a connecting seat. The top of the chopper fixedly penetrates through the middle of the connecting seat, the top of the connecting seat is fixedly connected with a connecting cylinder, and the top of the connecting cylinder is provided with a wire clamping assembly. By arranging the wire clamping assembly, the cleaning mechanism and the wire inlet cylinder, surface cleaning is completed while a gold wire automatically and straightly penetrates into the chopper, and the wire welding precision, reliability and packaging efficiency are effectively improved.

The application discloses a control method for high-voltage ride-through of an energy storage power station, and according to the different degrees of fault and working states, three control methods in three states are given, namely, under normal working conditions, the DC chopper does not act, and the energy storage PCS system outputs a given value of reactive current; under a light degree of fault, the DC chopper acts, and the energy storage PCS system outputs a given value of reactive current; and under a deep degree of fault, a dynamic reactive power compensation device is put into use, the DC chopper acts, and the energy storage PCS system outputs a given value of reactive current. The method can judge the degrees and states of high-voltage faults of a power grid by detecting the voltage of a grid-connected point of the energy storage power station, switches different control modes, protects the PCS converter part of the energy storage power station, and keeps the energy storage power station from being disconnected from the power grid within a certain time when the high-voltage fault occurs.

This power conversion device comprises: a chopper that has a switching element, and bidirectionally converts a battery voltage and a DC link voltage using the switching element; an inverter that bidirectionally converts the DC link voltage and an AC voltage; and a control device that controls the inverter and the chopper. The control device can select, as an operating mode for controlling the chopper, one of a first mode in which the DC link voltage is controlled in accordance with a voltage command value by turning on / off the switching element, and a second mode in which the switching element is always in an on state. The control device reduces the voltage command value when the operating mode is shifted from the first mode to the second mode.

The invention relates to a control system, which is composed of a main controller electrically connected to an AC chopper wall-controller, enabling users to control the AC chopper wall-controller by pressing, and the AC chopper wall-controller fully utilizes the principle of AC electricity and combining it with the characteristics of AC zero-crossing circuit, the main controller that controls an electrical appliance is capable of easily identifying signals, and at the same time, signals of the main controller will not be interfered due to a short power outage, thus capable of working stably.

This invention discloses a Sigma-Delta analog-to-digital converter (ADC) with aliasing suppression function. The Sigma-Delta ADC includes a preset loop filter module, a sampling module, a quantizer, and a preset feedback DAC module. The preset loop filter module, sampling module, and quantizer are connected in series. The preset loop filter module includes a chopper. The preset feedback DAC module is connected between the loop filter module and the quantizer to suppress aliasing introduced by the chopper and maintain the effective signal sampled by the sampling module within the corresponding frequency band. All poles of the transfer function of the preset feedback DAC module are located at the aliasing points introduced by the chopper, thus achieving the function of suppressing aliasing.

The application discloses a chopper AC to AC voltage converter, which comprises an AC input module, an input voltage detection circuit, a chopper switch module, a driving circuit, an AC output module, a control circuit and a power supply circuit, wherein the chopper switch module comprises a first switch tube and a second switch tube which are oppositely connected, and the chopper switch module is connected to the control circuit and the power supply circuit through the driving circuit. The first switch tube and the second switch tube are oppositely combined into a switch circuit to replace a thyristor, the first switch tube and the second switch tube are opened to output when the mains voltage is lower than a peak value of 200V, the first switch tube and the second switch tube are closed when the mains voltage is higher than the peak value of 200V, and the first switch tube and the second switch tube are opened again when the mains voltage is lower than the peak value of 200V, so that the output voltage is always lower than the peak value of 200V through the above-mentioned process, and the user's electronic and electrical products are prevented from being burnt due to the excessively high peak voltage.

The utility model discloses a spatial high-efficiency high-voltage direct current module, which belongs to the technical field of high-voltage direct current output and comprises an input rectifying and filtering module, a step-down chopper circuit module, a direct current DC1, a direct current DC2, a direct current DC1, a direct current DC1, a direct current DC1, a direct current DC2, a direct current DC1 and a direct current DC1, the three-phase LLC resonant inverter circuit module is used for converting direct current DC2 into high-voltage alternating current AC2, the output rectifying and filtering module is used for converting the high-voltage alternating current AC2 into high-voltage direct current DC0, and the fault isolating circuit module is used for isolating a fault part from other parts when the modules fail. According to the technical key points, the magnitude of the output voltage can be adjusted by controlling the on-off time of a full-control device IGBT (Insulated Gate Bipolar Transistor), so that the stability and the accuracy of the final output voltage are ensured, and in addition, the three-phase LLC resonant inverter circuit has relatively high conversion efficiency and relatively good electric energy quality, and can meet the requirement of high-efficiency high-voltage direct-current output.