398 results about "Switching cycle" patented technology

The invention relates to the technical field of micro-grids, and discloses an inverter output waveform optimization control method, an inverter and a storage medium, and the method comprises the steps: constructing a switching period average model and an output waveform optimization function of a single-phase off-grid inverter, and carrying out the optimization control of the output waveform of the single-phase off-grid inverter based on the output waveform optimization function and the switching period average model, determining a calculation model of a modulation wave compensation signal; acquiring an input signal for controlling the output waveform of the inverter, performing double closed-loop control on the inverter based on the input signal, and outputting an original modulated wave signal; calculating a modulation wave compensation signal based on the input signal, an inductive current reference value generated in double closed-loop control and a modulation wave compensation signal calculation model; and superposing the original modulated wave signal and the modulated wave compensation signal to obtain an optimized modulated wave signal. According to the method provided by the invention, the modulation wave signal is compensated and optimized, and the purpose of optimizing the waveform quality of the output voltage when the single-phase off-grid inverter is loaded with the nonlinear load is achieved.

The invention relates to an electromagnetic interference suppression method and device based on high-frequency GaN switching characteristics. The method comprises: in a power conversion circuit constructed based on a GaN switching device, edge analysis processing is performed on a driving signal of the GaN switching device to obtain edge feature data, and the edge feature data comprises a rising edge change rate and a falling edge change rate in a plurality of continuous switching periods; determining an equivalent network model constructed based on parasitic parameters in the power conversion circuit, and performing frequency domain response calculation on the equivalent network model according to the edge feature data, interference frequency band distribution information caused by the edge change is obtained, analysis processing based on spectrum energy adjustment is carried out on a driving signal of the GaN switching device according to the interference frequency band distribution information, and an adjustment control instruction used for restraining key frequency band interference is obtained. By adopting the method, an effective suppression strategy oriented to a specific interference frequency band can be realized.

A control unit for operating a power converter in a buck-boost mode is provided. The control unit is configured to, within a switching cycle, operate the power converter in an IN state starting from the beginning of the switching cycle until a timer signal of a timer occurs. The control unit is further configured to subsequently operate the power converter in a THROUGH state stating from the timer signal until a peak current event occurs. The control unit is further configured to subsequently operate the power converter in an OUT state starting from the peak current event until a clock signal occurs, which indicates an end of the switching cycle.

A control method and system for a resonant converter. The control method for a resonant converter comprises: in each switching cycle, determining a target power value on the basis of an input power control amount and a compensation amount corresponding to a bridge leg (S101); on the basis of the target power value, an input voltage, circuit parameters of the resonant converter, and the current operating mode of a full-bridge inverter module, determining a target slope control amount corresponding to a counter which corresponds to a switching transistor (S102); determining a comparison threshold on the basis of the target slope control amount, the current count value of the counter which corresponds to the switching transistor, and a DC bias voltage of a resonant capacitor corresponding to the current operating mode, wherein the counter starts counting using the DC bias voltage as an initial value in each switching cycle until the actual voltage of the resonant capacitor is equal to the comparison threshold (S103); and determining a control signal on the basis of the actual voltage of the resonant capacitor and the comparison threshold, and controlling the switching transistor on the basis of the control signal (S104).

A series-type hybrid circuit breaker to provide protection against short circuit faults in DC or AC power circuits. A series-type hybrid circuit breaker (SHCB) forces a fault current into a high-frequency AC current with zero crossings and allows a mechanical circuit breaker to disconnect the faulty branch. The SHCB injects a transient counter voltage pulse via a pulse transformer into the main power loop upon detection of an overcurrent condition and forces the fault current to change its original direction and cross zero to a negative peak value. A generation power electronic circuit on the primary side of the transformer controls the discharge of a capacitor to generate the counter voltage pulse during the first phase of each switching cycle of the fault interruption process. The power electronic circuit then changes the polarity of the injected secondary voltage and forces the fault current to change direction and cross zero again.

The application provides a transient frequency conversion control method of a converter and an electronic device. The method comprises the following steps: determining the working state of the converter, wherein the working state comprises a light load working state and a heavy load working state; if it is determined that the working state switches between the light load working state and the heavy load working state, starting a transient frequency conversion control strategy to adjust the switching frequency of the converter, wherein the transient frequency conversion control strategy is used to adjust the duration of the freewheeling stage in the switching cycle of the converter; after the working state of the converter switches, and the clamping capacitor voltage sampling value of the converter v c satisfies a preset condition, exiting the transient frequency conversion control strategy to restore the switching frequency of the converter to normal. The dynamic response speed of the converter is effectively improved, and the overshoot and drop of the output voltage when the converter is subjected to a step load are reduced.

The present application provides a power converter, comprising: a power conversion circuit and a control circuit. The power conversion circuit comprises an inverter circuit, a DC bus capacitor and a detection circuit, and the DC bus capacitor is connected in parallel with the inverter circuit. The DC bus capacitor comprises a positive bus capacitor and a negative bus capacitor connected in series. The inverter circuit comprises a bridge arm. The detection circuit is used to detect the voltage on both sides of the positive bus capacitor, the voltage on both sides of the negative bus capacitor and the output current of the bridge arm. The control circuit is used to control the bridge arm to switch from outputting two levels to outputting three levels within one switching cycle in response to preset conditions. The preset conditions are conditions based on the voltage of the positive bus capacitor, the voltage of the negative bus capacitor and the output current of the bridge arm. The present application uses a hybrid modulation of three levels and two levels, so that the power converter can achieve a balance between the quality of power output and power consumption, thereby improving the performance of the power converter.

The invention discloses a method for improving Buck light load efficiency, which can prevent pseudo CCM operation and can keep high light load efficiency even under a large duty ratio, and comprises the following steps: after soft start of a Buck converter is completed, an enable signal at the end of soft start sets an RS trigger U3 to be in an active state, and if an inductive current zero-cross detection trigger signal rises, the RS trigger U3 is in a non-active state, the RS trigger U3 is in a non-active state, and if the inductive current zero-cross detection trigger signal is in a non-active state, the RS trigger U3 is in a non-active state. When the high-end switch and the synchronous low-end switch are switched on, the setting end input of the RS trigger U3 is triggered, a switch starting signal output by the RS trigger U3 is set at the beginning of each switching period, the switch starting signal controls the constant on-time generator to modulate the charging current or capacitance so as to prolong the time of simultaneously switching off the high-end switch and the synchronous low-end switch, and when the synchronous low-end switch is switched on, the synchronous low-end switch is switched off. And the reset end of the RS trigger U3 inputs an output signal of the constant on-time generator to trigger the RS trigger U3 to reset.

Disclosed is a system for zero voltage switching in a power converter with a first half-bridge and a second half-bridge. The first half-bridge has a first set of transistors and output inductor. The second half-bridge has a second set of transistors and auxiliary inductor. A current sensing means measures, at switching cycle scale, average and maximum current values of output inductor and average, minimum and maximum current values of auxiliary inductor. A voltage sensing means measures input and output voltages of first and second half-bridge. A controller is configured to compute dead times of pulse width modulation control signal of second half-bridge, generate pulse width modulation control signal of second half-bridge and to adapt dead times of first half-bridge.

A conversion system includes a conversion device including a multilevel inverter configured to generate two alternating current (AC) output currents, a current sensor configured to sample a current through the multilevel inverter, or from the multilevel inverter, during a switching cycle, and a processor configure to estimate both of the two AC output currents based on the sampled current from the current sensor.

A power factor correction (PFC) control circuit includes a pulse-width modulation (PWM) circuit configured to control a switch of a switching power converter. The PFC control circuit further includes a mode control circuit configured to select a conduction mode from a plurality of conduction modes for the switching power converter based at least in part on an output power of the switching power converter and to control a beginning of a switching cycle of the switching power converter based on the selected conduction mode. In addition, the PFC control circuit includes a current regulation circuit configured to provide a regulation signal to the PWM circuit to regulate an average coil current of the switching power converter in each of the plurality of conduction modes.

The invention discloses a gallium nitride hybrid switched capacitor voltage converter with a high step-down ratio, which belongs to the technical field of switching power supplies and comprises an input filtering module, a switched capacitor module group, a half-bridge module group and an output filtering module which are connected in sequence, the switched capacitor module group comprises a plurality of switched capacitor modules which are connected in parallel, the half-bridge module group comprises a plurality of half-bridge modules which are connected in parallel, and the switched capacitor modules and the half-bridge modules are in one-to-one correspondence and work in corresponding preset switching periods; the output filtering module comprises a plurality of output filtering inductors, and the output filtering inductors are correspondingly connected with the half-bridge modules. Through innovation of the topological structure, the buck ratio higher than that of a traditional Buck converter under the same duty ratio is achieved, input current and output voltage ripples are further improved through a multi-phase interleaving parallel control mode, wide bandgap devices are reasonably selected for the innovatively-designed topological structure, and therefore the output current and output voltage ripples are improved. And the circuit is more suitable for kilowatt-level switching power supply equipment.

A system to generate weld power for a welding process comprises: a power supply including a power inverter having multiple switches controlled by multiple switching signals such that each switch is alternately turned ON and OFF within each switching cycle of one of the multiple switching signals, to supply a current to an output circuit of the power supply that is configured to convert the current to the weld power, wherein the power inverter includes a capacitor and a capacitor switch connected in series with each other and across a switch of the multiple switches; and a controller to monitor a weld parameter and control the capacitor switch to either connect the capacitor across, or disconnect the capacitor from, the switch continuously across multiple cycles of a respective one of the multiple switching signals, depending on whether the weld parameter meets a predetermined operating condition of the welding process.

The invention discloses an arc fault detection method. The method comprises the following steps: collecting a direct current side current of an inverter in real time; when it is determined that the direct current side current is the arc discharge signal, executing at least one of a first operation and a second operation: the first operation: sending a modulation switching instruction to the inverter to switch the inverter from the first modulation mode to the second modulation mode, and determining whether the direct current side current is the arc discharge signal again; in two adjacent switching periods, the common-mode voltage variable quantity of the second modulation mode is smaller than the common-mode voltage variable quantity of the first modulation mode; and the second operation: obtaining a zero crossing point moment of the three-phase modulation wave of the inverter, taking the zero crossing point moment as a center, collecting a direct-current side current in a set interval, and determining whether the direct-current side current is an arc discharge signal or not. According to the invention, misjudgment can be reduced, and the arc fault judgment accuracy is improved.

A control unit for transitioning a power converter between a buck mode and a buck-boost mode is provided. The control unit is configured to, detect a peak current event within a switching cycle while the power converter is operated in the buck mode, and upon detecting the peak current event, start a timer for generating a timer signal. Furthermore, the control unit is configured to determine whether or not the clock signal for starting a subsequent switching cycle occurs prior to the timer signal, and to operate the power converter in the buck-boost mode within the subsequent switching cycle, if the clock signal occurs prior to the timer signal.

A series-type hybrid circuit breaker to provide protection against short circuit faults in DC or AC power circuits. A series-type hybrid circuit breaker (SHCB) forces a fault current into a high-frequency AC current with zero crossings and allows a mechanical circuit breaker to disconnect the faulty branch. The SHCB injects a transient counter voltage pulse via a pulse transformer into the main power loop upon detection of an overcurrent condition and forces the fault current to change its original direction and cross zero to a negative peak value. A generation power electronic circuit on the primary side of the transformer controls the discharge of a capacitor to generate the counter voltage pulse during the first phase of each switching cycle of the fault interruption process. The power electronic circuit then changes the polarity of the injected secondary voltage and forces the fault current to change direction and cross zero again.

Aspects of the disclosure provide techniques for providing a UE capability indicating that the UE supports dynamic switching between a plurality of uplink frequencies within at least one frequency combination of at least three uplink frequencies. The UE capability may further indicate a respective switching period for each frequency pair within each of the one or more frequency combinations. The UE may further communicate with a network entity based on the UE capability.

A controller and method are for configuring operation of a kVp-s witching spectral CT imaging apparatus which, in at least one mode, aims to mimic the user-side operating workflow of a conventional non-spectral CT scanner. The controller receives user-defined settings associated with operation of a non-spectral CT system, comprising a desired peak tube voltage and desired tube current. Based on these user-specified inputs, the controller performs a conversion procedure to derive a set of spectral CT operating parameters which are estimated to result in administration of the same dose of X-ray radiation over a single kVp switching cycle as would be administered by the conventional scanner over a same time duration. Thus, the user can acquire CT projection and image data using a spectral CT scanner, without a need to change their own operating workflow, and furthermore in a way that will administer the same radiographic density as they would expect to achieve with the same user-specified settings on a conventional scanner.

The invention provides a control method of a power converter and the power converter, and the power converter comprises a first switch, a second switch, a first driving unit and a second driving unit which correspond to the first switch and the second switch, and a bootstrap capacitor which supplies power to the second driving unit. The bootstrap capacitor is charged through a first switch, and the control method comprises the steps that when the duty ratio of the first switch is reduced to a first threshold value, the duty ratio of the first switch is controlled to be a preset duty ratio every time at least one switching period is passed, and the preset duty ratio is not smaller than the first threshold value. The voltage of the bootstrap capacitor of the second switch can be stabilized, meanwhile, overshoot of inductive current can be avoided, the output voltage can be prevented from being too large, and then the circuit is protected.

A method for driving a transistor is described herein. In accordance with one embodiment, method includes modulating an output voltage by cyclically switching a transistor on and off, wherein, in each switching cycle, a gate current having a first current level is supplied to the transistor to switch the transistor on. The method further includes determining a characteristic time parameter of the output voltage (e.g. a rise or a delay time) and determining an error representing the difference between the determined time parameter and a target time in each switching cycle; adjusting the first current level based on the error; and detecting an oscillation of the error. When an oscillation is detected, the adjustment of the first current level is paused until the magnitude of the error exceeds a threshold value in a second number of consecutive switching cycles.

A control unit for operating a power converter in a boost mode is provided. The control unit is configured to detect a peak current event within a switching cycle, and upon detecting the peak current event, to start a ramp signal for the detection of a peak current event in a subsequent switching cycle.

The invention relates to an operation mode control technique for a power factor correction circuit. A power factor correction (PFC) control circuit includes a pulse width modulation (PWM) circuit configured to control a switch that switches a power converter. The PFC control circuit also includes a mode control circuit configured to select a conduction mode from a plurality of conduction modes for the switching power converter based at least in part on an output power of the switching power converter, and controlling a start of a switching cycle of the switching power converter based on the selected conduction mode. Further, the PFC control circuit includes a current regulation circuit configured to provide a regulation signal to the PWM circuit to regulate an average coil current of the switching power converter in each of the plurality of conduction modes.

A control device includes a PWM control unit, a current detector, and a short circuit detector. The PWM control unit outputs a control signal to the driver of a multiphase power supply in which the inductors of each phase are configured by a coupled inductor, and controls an on / off of the driver. The current detector detects the current flowing through the driver. The short circuit detector detects an inter-inductor short circuit based on a switching cycle of the driver and a current value detected by the current detector. The short circuit detector determines that an inter-inductor short circuit occurs between phases including a given phase when a differential value of the current value corresponding to the given phase is positive and greater than or equal to a threshold value during an off period of the driver in the given phase.

The invention relates to a method (100) for determining power data of electronic power circuits, comprising determining a plurality of switching energy values (110) during a periodic duration of a control signal of the electronic power circuit; and determining the power data (120) which have a switching cycle energy value that is determined on the basis of the plurality of switching energy values and a number of times the plurality of switching energy values are determined. The invention further relates to a computing unit for determining power data, which computing unit is designed and configured to carry out the method.

The application discloses an asymmetric phase-shifting control method suitable for a half-wave shaping MMC, and can realize wide-range operation energy balance of a converter. The method is characterized in that, in a 2pi period, a commutation unit switching function and a multi-level unit modulation voltage are not switched in a half-wave period pi, but in a positive half-wave mode, [0, pi] is taken as a reference to expand and shift an angle theta to the left and right, that is, the interval is [-theta, pi+theta], and in a negative half-wave mode, [pi, 2pi] is taken as a reference to shrink and shift an angle theta to the left and right, that is, the interval is [pi+theta, 2pi-theta]. The application adopts an asymmetric phase-shifting modulation method, generates and reverses polarities of two asymmetric partial sine waves through a commutation switch cooperating with a multi-level unit, and obtains a complete multi-level sine wave on an alternating current side. The application can eliminate the limitation of a power factor angle on a phase-shifting angle while realizing wide-range energy balance of the converter, is only affected by a modulation ratio, and compared with symmetric phase-shifting modulation, is beneficial to simplifying commutation control logic when the system is in a wide-range reactive power regulation, and has better engineering application value.

A system may include a modulator configured to generate switching signals for a switching circuit based on a control variable, the modulator comprising a quantizer configured to, for a range of values of the control variable within a predetermined difference from a boundary of the control variable between a first operational mode and a second operational mode of the switching circuit, bias the control variable by a bias amount to increase a probability of operating the switching circuit in the first operational mode for a switching cycle if a previous switching cycle of the switching circuit was in the second operational mode; and increase a probability of operating the switching circuit in the second operational mode for the switching cycle if the previous switching cycle of the switching circuit was in the first operational mode.

This invention relates to the fields of semiconductor information storage and artificial synaptic devices, specifically to a biological synaptic intrinsically self-assembled topological phase-change memristor and its fabrication method. The fabrication method includes: providing a substrate; depositing a bottom electrode; and depositing SrFeO on the bottom electrode. x The thin film serves as the storage medium layer; the storage medium layer undergoes heat treatment, including in-situ annealing and post-annealing. By controlling the oxygen pressure difference between in-situ and post-annealing, the single-component SrFeO is made more efficient. x An intrinsically self-assembled superlattice structure, characterized by alternating vertical and horizontal orientation regions of oxygen vacancy channels, spontaneously forms within the thin film. This structure restricts the formation sites of conductive filaments, significantly improving the consistency and stability of the device's resistive switching cycle. The process of this invention is simple, requiring no introduction of a second-phase material. The resulting memristor requires no electrical formation, exhibits a high on / off ratio, multi-level storage, and short-term synaptic plasticity, making it applicable to neuromorphic computing chips and artificial intelligence devices.

A power converter includes a transformer, a main switch, an active clamp switch, and a primary side controller circuit. The primary side controller circuit is configured to indirectly measure a magnetizing current through the transformer during a first switching cycle of the power converter and estimate a zero-crossing point of the magnetizing current for a second switching cycle based on the indirect primary side measurement of the magnetizing current. Based on the estimated zero-crossing point, the primary side controller circuit generates an auto-tuned delay, for the second switching cycle, between disabling the main switch and enabling the active clamp switch before the zero-crossing of the magnetizing current occurs. The active clamp switch is enabled during the second switching cycle in accordance with the auto-tuned delay.

The embodiment of the invention discloses a power evaluation method, device and equipment for a gravity energy storage array system, and the method comprises the steps: constructing a model of the gravity energy storage array system; constructing an operation state difference evaluation index based on the operation number of the gravity energy storage units and the number of weight blocks input by the gravity energy storage units; under the condition that the operation state difference evaluation index meets a preset condition, the estimated adjustment power of the gravity energy storage unit in the switching period of the weight block is determined, determining a power adjustment estimation range based on the model, the operation number of the gravity energy storage unit, the number of weight blocks input by the gravity energy storage unit, the power variation of a single weight block and the estimation adjustment power; and determining power evaluation of the gravity energy storage array system in the charging and discharging state based on the power adjustment estimation range. According to the technical scheme provided by the embodiment of the invention, the power of the gravity energy storage array system can be accurately evaluated, and a reliable basis can be provided for power dispatching.

A controlling method of a power converter includes performing a first switch controlling step and a second switch controlling step. The first switch controlling step is performed to control a primary switch of the power converter by a first controlling signal. The second switch controlling step is performed to control an active clamp switch of the power converter by a second controlling signal. The primary switch is turned on by the first controlling signal at each of a plurality of power converter switching cycles. The active clamp switch is not turned on by the second controlling signal at a part of the power converter switching cycles, and the active clamp switch is turned on by the second controlling signal at another part of the power converter switching cycles.