459 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 relates to the technical field of integrated circuit design, and particularly discloses a low-noise programmable amplifier, which comprises a first fully-differential amplifier, a second fully-differential amplifier, a third fully-differential amplifier and a fourth fully-differential amplifier, the second fully differential amplifier comprises a pair of differential input ends and is electrically connected with the first fully differential amplifier through an interstage chopper switch; a pair of input chopping switches, wherein the input end of each input chopping switch is electrically connected with a differential input signal; the output end of each output chopping switch is electrically connected with the output end of the second fully differential amplifier; the input capacitance network is positioned between the pair of input chopping switches and the two pairs of differential input ends; the feedback capacitance network is positioned between the pair of output chopping switches and the two pairs of differential input ends; and the plurality of zeroing switches are positioned between the input and the output of the first fully differential amplifier. The two transconductance amplifiers in the first fully-differential amplifier share the same current, the overall transconductance is doubled compared with single-pair differential input, and the noise of the amplifier is reduced.

An in-vehicle charging device that includes an AC-DC converter that converts power between AC power on the external AC power supply side and first DC power; and a DC-DC converter that converts power between the first DC power and second DC power on the DC power supply side, wherein the AC-DC converter includes a current source active rectifier having a power factor correct function, the DC-DC converter includes a chopper circuit including a reactor disposed on the AC-DC converter side and a half-bridge circuit disposed on the DC power supply side, the reactor is configured using a plurality of the coils, the half-bridge circuit is configured using the inverter, and the current source active rectifier includes a bidirectional switching device.

The invention discloses a full-automatic deep-cavity ball-wedge integrated bonding head device, which belongs to the technical field of semiconductor packaging equipment and comprises a bonding head base body, an ultrasonic transducer, a wire clamp assembly, a chopper, a wire guider assembly and an ignition needle assembly. The chopper is detachably mounted on the ultrasonic transducer, and the chopper can be selectively a ball bonding chopper or a wedge bonding chopper; the wire guide device assembly at least comprises a wire guide piece which is detachably installed, and when the chopper is a wedge welding chopper, the wire guide piece is arranged on the side face of the bottom of the chopper and used for providing restraining force for a welding wire at the bottom of the chopper. The ignition needle assembly is detachably installed on a Z-direction stator of the bonding equipment, and when the chopper is a ball bonding chopper, the ignition needle assembly is used for being matched with the chopper to complete welding wire ball burning. According to the invention, the integrated design of the ball bonding head and the wedge bonding head and the rapid switching of the two processes are realized, the multi-process requirements are met, the equipment cost is reduced, and the production efficiency is improved.

A system for evaluating a sample, the system includes (i) a chopper that includes (i.1) a disc that is made of a transparent material that bears an inner opaque pattern and outer opaque pattern, the outer opaque pattern surrounds the inner opaque pattern, and (i.2) a rotating unit that is configured to rotate the disc during a modulation period, (ii) first optics, (iii) second optics, (iv) a control unit that is configured to detect a second modulated beam from the second optics, and control the rotating unit based on at least one parameter of the second modulated beam.

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.

First and second bases are arranged to face each other. An inverter is mounted on either of the first and second bases. A converter is mounted on the first base. A chopper is mounted on the second base. At least some of fins thermally connected to the converter via the first base are thermally connected to the chopper via the second base.

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 discloses a network construction type energy storage variable power factor control method considering reduction of a network loss demand, and the method comprises the steps: changing a control target of an energy storage converter: controlling the voltage of a DC bus through a chopper, controlling the power output of energy storage through the converter, designing a power synchronization link in the control of the converter, and controlling the power output of the energy storage through the converter; the inertia and damping characteristics are realized; an energy storage target power factor is determined according to system network loss, a virtual impedance value is calculated, corresponding voltage is compensated to a converter voltage control ring, and output power is adjusted. According to the invention, network construction transformation is carried out for traditional network following type energy storage, the target power is utilized to calculate the virtual impedance before the virtual impedance is fed to the voltage environment, the virtual impedance is matched with the internal potential dq-axis component, and the output power is adjusted, so that the wide-range operation capability of the energy storage power factor is improved, and the reduction of the system network loss is facilitated.

The invention discloses a hydrogen production power supply system and a control method thereof. The system comprises a transformer, a main power branch, an auxiliary power branch, at least one group of energy storage branches and a bus bar, a primary winding of the transformer is coupled to an alternating current power grid, and a secondary winding is coupled to the input end of the main power branch; the output end of the main power branch is coupled to the off-grid hydrogen production equipment; the auxiliary power branch is coupled between the secondary winding and the bus bar; the energy storage branches are coupled to the bus bar; the main power branch comprises at least one group of uncontrolled rectifying circuits and at least one group of chopper circuits, the uncontrolled rectifying circuits are used for converting alternating current output by the transformer into direct current, the cost is low, and the chopper circuits are used for adjusting the voltage of the direct current into the voltage required by a load of the chopper branch; the auxiliary power branch is used for outputting power to the bus bar and performing power interaction with an alternating current power grid to improve the response capability to the alternating current power grid; and the energy storage branch is used for pre-storing and releasing electric energy through the bus bar, so that the system stability is improved.

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.

The invention discloses a welding machine chopper circuit control method and device based on multistage power regulation, and relates to the related field of chopper control, and the method comprises the steps: determining a circuit topology structure which comprises a main circuit topology and an auxiliary circuit topology based on chopper control; the dual-drive control module is supervised and trained based on hybrid modulation of the duty ratio and the switching frequency; receiving a welding task and determining a frequency modulation sequence; dividing multi-stage power features and mining a Markov frequency modulation chain; the combined digital signal processor and the programmable controller construct a control loop; and receiving a frequency modulation sequence and a precursor control signal, executing a chopping frequency modulation control decision and signal conversion based on a control loop, and performing chopping circuit control response. The technical problem that the welding process is unstable due to the fact that the control precision of an existing chopper circuit of the welding machine is insufficient is solved, and the technical effect of improving the control precision and stability of the welding process is achieved.

The invention discloses a novel chopping correlation double-sampling stable multi-path amplifying circuit and method, and relates to integrated circuit design. A Miller compensation capacitor in a chopping stable multi-path CSMP amplification circuit architecture is utilized to design a chopping correlation double-sampling circuit, and compared with a traditional correlation double-sampling circuit, a group of sampling capacitors and sampling switches are reduced. Large capacitance and large resistance required by a traditional high-pass filter circuit are eliminated, and the layout area and the current required for driving a high-pass filter capacitor are reduced; and thermal noise caused by large resistance in the passive high-pass filter is reduced, and the input equivalent noise density is improved. Through an offset calibration technology, the stability of the CSMP architecture is ensured, and the offset voltage is reduced at the same time; output ripples are suppressed by using the high-pass performance of the novel chopping correlation double-sampling circuit, 1 / f noise is reduced, and input equivalent noise density is reduced. The advantages of the chopping correlation double sampling technology and the stable multi-path amplification circuit are combined, and the advantages of low offset, low output ripple and low input equivalent noise density are achieved.

The invention provides a DRU system based on a blocking type auxiliary current converter and a starting method of the DRU system. The DRU system comprises a shore current converter, an offshore rectifier and an offshore auxiliary current converter. The starting method comprises four stages. A V / f control strategy is adopted for activating a shore converter control system and a blocking type auxiliary converter, and an offshore alternating-current power grid is established; the chopper circuit is triggered, and the circuit breaker is safely disconnected by using a zero-current switching technology; the offshore wind plant quits the low-voltage ride-through mode, and starting of the DRU system is completed; according to the invention, by introducing the blocking type auxiliary current converter and combining the DRU and the main current converter, black start and stable operation of the wind field are realized; moreover, the system has the characteristics of quick response and high reliability, can quickly establish AC voltage in the starting stage, and provides required starting energy for the wind turbine generator. The auxiliary converter can provide reactive power support and harmonic suppression during normal operation of a wind field, and the stability and efficient operation of the system are ensured.

The invention discloses a wireless power transmission double-closed-loop compound control system and method based on LCC-S compensation, aims at the problem that the transmission efficiency of a wireless power transmission system is reduced due to load change, adopts a PI algorithm and a fuzzy PID algorithm to respectively control a primary side full-bridge inverter circuit and a secondary side DC-DC step-down chopper circuit, and has the advantages of simple circuit structure, low cost and the like. Reliability is high, efficiency is high, and maximum efficiency tracking of a wireless power transmission system is achieved.

The invention discloses an offset cancellation circuit, which comprises a signal conditioning unit used for processing an input signal and outputting a first current signal, an offset cancellation unit used for removing offset current in the first current signal and outputting a second current signal, and a signal processing unit used for processing the second current signal and eliminating offset voltage, the detuning elimination unit specifically comprises a chopper, a digital analog converter, a successive approximation register logic module and a comparator which are connected in sequence, and through multi-level detuning elimination, the precision of the whole circuit is improved, the processing capacity for weak signals is enhanced, the anti-interference capacity is improved, and noise is reduced; the method ensures the stability of long-time operation, and has a wide application prospect in the field of high-precision signal processing.

A voltage detection circuit includes an AD converter, an input chopper circuit, an output chopper circuit, a digital low-pass filter, and a current chopper circuit. The chopper circuit switch a connection state of each input terminal of the AD converter, first and second input wirings at a first frequency. The output chopper circuit alternately execute inverting and non-inverting operations for an output value of the AD converter. The digital low-pass filter removes a high-frequency component from the output value of the output chopper circuit and operates at an output frequency. The current chopper circuit switches the connection state of a first current source, the first input wiring, a second current source and the second input wiring at a second frequency.

The invention discloses a transient reactive characteristic modeling method for a flexible excitation system under a power grid voltage fault, and the structure and a control block diagram of the system meet the following requirements: a synchronous generator is connected with a three-phase voltage source type converter, the three-phase voltage source type converter is connected with a chopping converter, the chopping converter outputs excitation voltage according to a system control signal, and the excitation voltage is converted into the excitation voltage. Therefore, excitation current is provided for the synchronous machine. The modeling process comprises the following steps: analyzing a synchronous machine equivalent diagram and an AVR control block diagram in the flexible excitation system so as to establish a corresponding mathematical model; then voltage and current parameters of a synchronous machine end of the system in a steady state before a fault are calculated; the transient current caused by the stator voltage change and the excitation voltage change is further solved respectively; and finally, the transient reactive power of the synchronous machine side of the flexible excitation system is obtained. The method provides a theoretical basis for realizing dynamic strong excitation control of the flexible excitation system and improving the stability of the system under a transient condition.

Provided is a potentiostat-based electrochemical sensor detection device. The device comprises: a digital-to-analog converter (DAC) configured to receive a digital signal from a waveform generator and digital logic and output an analog signal corresponding to a reference voltage; a control amplifier (CA) configured to receive the analog signal corresponding to the reference voltage and apply the reference voltage to a reference electrode (RE); a gain-boosting current mirror configured to copy a sensor current of an electrochemical sensor and output a copied sensor current; a transimpedance amplifier configured to convert the copied sensor current into a voltage signal; a low-pass filter configured to block a high-frequency band signal component of the voltage signal; and an analog-to-digital converter (ADC) configured to perform digital signal processing on a signal having passed through the low-pass filter, wherein at least one of the gain-boosting current mirror and the transimpedance amplifier employs a dynamic element matching (DEM) technique using a plurality of choppers and a plurality of DEM clock signals.

The invention discloses a non-isolated quasi-series-parallel combined converter based on a switched capacitor network. The converter comprises the switched capacitor network, a non-isolated DC-DC converter, an output filter capacitor Co and a load resistor R. The combined converter gives full play to the advantages of high power density and high efficiency of a non-voltage-regulation mode of the resonant switched capacitor converter, the resonant switched capacitor network and the DC-DC chopper converter are subjected to topological combination through a partial power processing technology, and the combination has the advantages of high power density and high efficiency of the non-voltage-regulation mode of the resonant switched capacitor network and also has the advantages of high power density and high efficiency of the non-voltage-regulation mode of the DC-DC chopper converter. And the advantage of wide voltage regulation range of the DC-DC chopper converter is also fused. By means of the time-sharing charging and discharging characteristics of the capacitors, the resonant switched capacitor network and the DC-DC chopper converter are connected in series on the input side to reduce voltage stress and are connected in parallel on the output side to replace a traditional two-stage cascade mode, and higher total electric energy conversion efficiency is achieved.

The invention discloses a superconductive phase modifier excitation power unit with adjustable top value voltage and a control method thereof, and the power unit comprises the following modules which are connected in sequence: the input end of a PWM rectifier module is connected with an excitation power supply, and AC / DC conversion is carried out on the input voltage of the excitation power supply; the DC bus support capacitor module realizes output DC voltage support of the PWM rectifier module; the DC chopper module realizes DC / DC chopping output of the DC bus voltage according to the excitation requirement of the generator; the voltage smoothing module is used for smoothing and filtering the chopping pulse voltage output by the direct current chopper module; and the output end of the voltage commutation module is connected with the superconducting rotor and is used for realizing rectification of rotor excitation current and conversion of an inversion loop. According to the technical scheme, the excitation voltage and the excitation current can be adjusted stably in the steady state, the effect of the high excitation multiple can be exerted in the transient state and the dynamic state to improve the quick response capacity of the system, and meanwhile the excitation inversion capacity is achieved to achieve quick reduction of the excitation current.

The invention relates to a dynamic ripple elimination circuit for a linear Hall signal amplifier, and belongs to the technical field of circuits. The dynamic ripple elimination circuit for the linear Hall signal amplifier comprises a ripple extraction network, a fully differential integrator, a chopper and a disappearance tone buffer which are connected in sequence, and the ripple extraction network extracts ripple signals in output signals of the amplifier; and through integration, chopping and buffering, a compensation signal for eliminating ripples is generated and injected into a main loop of the amplifier, and the ripples in an output signal of the linear Hall signal amplifier are eliminated. Therefore, a low-pass filter does not need to be adopted at the rear stage, adverse effects on the bandwidth are avoided, and the circuit is simple in structure and quite wide in application range.

The invention discloses a ping-pong self-stabilization zero-loop ripple suppression precision operational amplifier, which comprises a high-frequency path and a low-frequency path, and is characterized in that the high-frequency path comprises a third transconductance amplifier Gm3 and a fourth transconductance amplifier Gm4; the low-frequency path comprises a first transconductance amplifier Gm1-Gm3, a second transconductance amplifier Gm1-Gm3, a first chopper Cop1-Cop2, a second chopper Cop1-Cop2 and a ping-pong self-stabilization zero ripple suppression loop, and the ping-pong self-stabilization zero ripple suppression loop is used for suppressing offset voltage and output ripple generated by the low-frequency path. The invention designs a ping-pong self-stabilizing zero ripple suppression feedback (AZCFB) loop, the self offset voltage of the ripple suppression loop is eliminated by adopting an automatic zeroing technology, and the residual offset is filtered by a chopper and a filter. In addition, a high-pass filter is used for eliminating the influence of AZCFB loop sampling node direct-current potential deviation on output ripples, and the purpose of restraining the output ripples is achieved.

The disclosure is directed to a brake chopper, a control board, a bus voltage control method, a device and a medium. The brake chopper may include a resistor module, electrically connected to a DC bus to form an energy release circuit of the DC bus; a control module, for determining the difference between a voltage value of the DC bus and a preset first threshold, and generating a first switch control signal on the basis of the difference; and a switch module, for controlling the ON time of the energy release circuit on the basis of the first switch control signal. There may be a progressively increasing relationship between the ON time and the difference. The ON time of the energy release circuit may be precisely controlled based on the difference between 10 the DC bus voltage value and the first threshold, increasing the energy utilization rate of the DC bus.

The invention discloses a mobile energy storage ice melting system and method based on intelligent control of a chopper circuit. The ice melting device comprises a switch module, a chopping ice melting module, an energy storage power supply module and a control module, the energy storage power supply module, the chopping ice melting module and the switch module are sequentially connected to form a loop, two ends of an ice coating line are connected to the loop, and the control module is used for calculating current needed by ice melting, calculating voltage needed by ice melting according to the current needed by ice melting and controlling the voltage needed by ice melting. According to the voltage required by ice melting and the actual output voltage of the chopping and ice melting module, the switch module is controlled to select the chopping and ice melting module to boost or buck; the total capacity required by ice melting in the ice melting process of the ice-coated line is calculated according to the current required by ice melting, and the capacity and the number of the energy storage power supply modules are selected according to the total capacity required by ice melting. The output current is direct current, an alternating current power supply does not need to be rectified into a direct current power supply through six-pulse wave or twelve-pulse wave rectification, and the advantages of being high in efficiency, small in size, easy to integrate and low in cost are achieved.

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 bidirectional chopper selectively performs a charging operation and a discharging operation, the charging operation being an operation in which a part of DC power generated by a converter is stored in a power storage device, the discharging operation being an operation in which DC power of the power storage device is supplied to an inverter. A control circuit controls the bidirectional chopper to perform the discharging operation when a power failure of a power system occurs. The control circuit controls the bidirectional chopper based on a system frequency detected by a frequency detector when the power system is normal. The control circuit controls the bidirectional chopper to perform the charging operation in response to an increase in the system frequency, and to perform the discharging operation in response to a decrease in the system frequency.

Embodiments disclosed herein include a method of training a DNN. A processor initializes an element of an A matrix. The element may include a resistive processing unit. A processor determines incremental weight updates by updating the element with activation values and error values from a weight matrix multiplied by a chopper value. A processor reads an update voltage from the element. A processor determines a chopper product by multiplying the update voltage by the chopper value. A processor directs storage of an element of a hidden matrix. The element of the hidden matrix may include a summation of continuous iterations of the chopper product. A processor updates a corresponding element of a weight matrix based on the element of the hidden matrix reaching a threshold state.