496 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.

A half-bridge driver circuit periodically repeats switching cycles by closing a first FET via a first drive signal, detecting an instant when a current flowing through the first FET reaches a threshold and then opening the first FET and closing a second FET via a second drive signal. An error amplifier generates a control voltage by comparing a feedback signal with a reference signal, and a variable current generator generates a first current as a function of the control voltage. The error amplifier includes a proportional-integral controller, and a slope compensation circuit that generates a second current as a ramp signal. The threshold is generated by subtracting the second current from the first current. In response to detecting the instant, the second current is sampled and a signal indicative of the threshold is generated by subtracting the sampled second current from the first current.

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.

Disclosed in the present invention are a switching converter and a zero-crossing detection circuit thereof. The zero-crossing detection circuit comprises: a low-side transistor control circuit used for generating a low-side transistor control signal on the basis of a high-side transistor control signal; a switching node voltage detection circuit used for generating a first pulse signal having a first pulse width when a synchronous power transistor is turned off in each switching cycle, and generating a second pulse signal having a second pulse width on the basis of a comparison result between a turn-off moment of the synchronous power transistor and an inductor current zero-crossing moment; and a phase-locked loop circuit used for providing a delayed current signal to the low-side transistor control circuit on the basis of the first pulse signal and the second pulse signal, so that the low-side transistor control circuit controls an effective level time of the low-side transistor control signal in a next switching cycle on the basis of the delayed current signal. Therefore, the inductor current can fluctuate within a tiny interval near 0 A, improving the accuracy of zero-crossing detection, reducing the circuit loss of the switching converter, and improving the efficiency of the switching converter.

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 flyback converter comprising: a transformer having a primary side winding and a secondary side winding; a primary side switch located at the primary side of the transformer; two secondary side switches located at the secondary side of the transformer; in which the two secondary side switches are connected in parallel and have different characteristics; and a control unit configured to generate a rectification signal and a Zero Voltage Switching (ZVS) pulse and to drive the two secondary side switches; in which a secondary side switch is driven by the rectification signal and the other secondary side switch is driven by the ZVS pulse. At the end of a switching cycle, before turning on the primary side switch: the control unit is configured to generate the ZVS pulse in the secondary side winding such that the parasitic capacitor of the primary side switch is discharged, and to consequently turn on the primary side switch in ZVS conditions or near ZVS conditions.

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.

A power switching circuit includes a driving signal part, a first switch element, a second switch element, a first driving circuit and a second driving circuit. The first driving circuit includes a first resistor and a first connection branch, which are connected between a positive driving signal terminal of the driving signal part and a first driving terminal of the first switch element, respectively. The second driving circuit includes a third resistor and a second connection branch, which are connected between the positive driving signal terminal and the second driving terminal of the second switch element, respectively. In a same switching cycle, the turn-on time of the first switch element is earlier than the turn-on time of the second switch element and the turn-off time of the first switch element is earlier than the turn-off time of the second switch element.

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.

Controller and method for a switching power supply. For example, a controller for a switching power supply includes: a first terminal configured to receive a feedback voltage representing an output voltage associated with a secondary winding of the switching power supply; a second terminal configured to output a drive voltage to a first transistor associated with a primary winding coupled to the secondary winding of the switching power supply; a comparator configured to receive the feedback voltage and a predetermined feedback threshold and generate a comparison signal based at least in part on the feedback voltage and the predetermined feedback threshold; a pulse-width detector configured to detect a pulse width of the drive voltage during a first switching cycle, compare the detected pulse width with a predetermined time threshold, and generate a detection signal based at least in part on the detected pulse width and the predetermined time threshold.

A ripple voltage detector circuit comprises a pulse generator, a direct current-to-direct current (DC-DC) converter coupled to the pulse generator, and a first control loop coupled to the pulse generator and the DC-DC converter. The first control loop is configured to measure an output voltage of the DC-DC converter, determine an output ripple voltage of the output voltage, determine a ripple coefficient based on the output ripple voltage, determine a reference peak inductor current based on the ripple coefficient, and determine a peak value of an inductor current during a switching cycle, and transition a switching state of the DC-DC converter based on the reference peak inductor current and the peak value of the inductor current.

The invention discloses an optimal switch time sequence design and modulation method for single-phase circulating current suppression of two parallel converters. The method comprises the following steps: firstly, screening 32 switch combinations which only introduces a certain phase of single-phase circulating current or does not introduce any single-phase circulating current from all 64 switch state combinations; secondly, designing a switching time sequence corresponding to the whole vector plane by using 32 switch combinations and considering the balance and switching times of single-phase circulating current in a switching period; in view of mutual overlapping of the time sequence modulation areas, single-phase circulation peak values of the time sequences are further compared to determine the optimal modulation areas, and then in view of redundancy of the time sequences in the optimal modulation areas, single-phase circulation effective values of redundant time sequences are further compared, and final sector division is determined according to the minimum effective values. And finally, designing action rules of modulation waves and carrier waves corresponding to each time sequence. The method solves the problem that an existing modulation method does not suppress the high-frequency single-phase circulating current of the two parallel converters.

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.

The invention discloses a measurement method in a switching mode, a configuration method of the switching mode, a node and a medium. The measurement method in the switching mode comprises the following steps: receiving switching mode configuration configured by a second communication node under the condition that a first communication node works in a plurality of aggregated resources, the switching mode configuration is used for indicating the first communication node to carry out signal transmission on a first resource in a first time period and carry out signal transmission on a second resource in a second time period, and the switching mode configuration at least comprises configuration of a switching period; and measuring the target resource according to the switching mode configuration.

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.

The object of the invention is a mixing system (1) comprising at least a boiler (2) and a heat pump (3) through which technical fluids for room heating and / or for domestic water production circulate, and an associated method for managing and controlling the switching cycle (ON / OFF) of said heat pump (3) during domestic hot water (DHW) intake. The method comprises at least the following steps: during said domestic hot water (DHW) water intake, ensuring flow to the heat pump (3) at a flow rate mchHP at least adapted to avoid closing thereof, and ensuring a complete achievement of this DHW water intake.

Controller and method for a power converter. For example, a controller for a power converter includes: a mode detector configured to determine a mode of operation for the power converter; a first gate driver configured to output a first drive voltage to a first transistor related to a first auxiliary winding coupled to a primary winding, a secondary winding, and a second auxiliary winding; a second gate driver configured to output a second drive voltage to a second transistor related to the primary winding; wherein the first gate driver is further configured to, if the mode of operation satisfies one or more first predetermined conditions, generate the first drive voltage so that the first transistor remains turned off during a switching cycle of the power converter.

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.

The present disclosure provides an active clamp flyback converter and a control method, and relates to the technical field of converter. The control method includes: in response to that an input voltage of the active clamp flyback converter is less than a preset voltage threshold, or the input voltage of the active clamp flyback converter is less than a product of an output voltage of the active clamp flyback converter and a turns ratio of the transformer, in a same switching cycle, controlling the clamp switch to turn on when the transformer is in a demagnetization stage; and controlling the clamp switch to turn off when a resonant current of the clamp capacitor and a leakage inductance of the transformer reaches a preset current threshold.

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.

The invention discloses a three-level DC / DC device open-circuit fault judgment method, and the method comprises the following steps: selecting a DC / DC unit corresponding to a photovoltaic string as a to-be-tested DC / DC unit, and carrying out the driving blocking of the DC / DC units corresponding to other photovoltaic strings; acquiring an inductive current and a bus voltage of the DC / DC unit to be tested; judging an open-circuit fault of the DC / DC unit to be tested based on the inductive current change value or the bus voltage deviation in the single-switch period; or the open-circuit fault of the DC / DC unit to be tested is judged based on the combination of the inductive current change value and the bus voltage deviation in the single-switch period; and reselecting the DC / DC unit to be tested until all the DC / DC units finish open-circuit fault judgment. The beneficial effects of the invention are that the open-circuit fault of the three-level DC / DC unit can be monitored through software, and the open-circuit fault can be accurately positioned.

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.

A method implemented by a control circuit reduces electromagnetic interference (EMI) generation in a switched-mode power supply. The power supply adjusts operating frequency in response to a change in operating condition, and the method avoids certain bands of frequencies, for which switching should be avoided to avoid generating EMI in the band(s). The method includes determining a disallowed cycle time period range corresponding to the band(s) of frequencies by detecting that a switching event for the adjusted operating frequency would cause a switching cycle period to be within the disallowed time period range, and in response, preventing switching of the switched-mode power supply that would cause an end of a switching cycle to occur within the disallowed cycle time period range, and permitting switching of the switched-mode power supply that would cause the end of the switching cycle to occur outside of the disallowed cycle time period range.

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.