97 results about "Active clamp" patented technology

The invention relates to the technical field of series voltage sharing of power electronic power devices, in particular to a dynamic voltage sharing circuit of a high-voltage integrated gate commutated thyristor (IGCT) series valve group and a control method of the dynamic voltage sharing circuit of the high-voltage IGCT series valve group. The voltage is monitored in real time; the overvoltage energy release unit is used for releasing transient overvoltage energy; all the active clamping circuits are connected in series to form a clamping matrix, corresponding overvoltage energy discharge units are triggered when overvoltage is detected, and transient voltage sharing is optimized by the central controller in combination with an arbitration strategy. By improving the voltage balancing capability between the IGCT device valve group modules, transient overvoltage energy can be quickly sensed and released, the dynamic voltage balancing problem is effectively solved, the system operation stability is improved, meanwhile, the power consumption in the online operation process is remarkably reduced, the size of a heat dissipation system is reduced, and the power density of the converter valve is greatly improved.

An isolated switching power supply circuit is compact, high-efficiency, and low noise. It includes a transformer T1 which has a primary winding wound with NP turns and a secondary winding wound with NS turns, a drive switch Q1 and an active clamp switch Q2 configuring a primary side half-bridge, a boost capacitor CBULK1 that charges a discharge energy of the transformer, rectifier diodes D1 and D2 connected in series, a tank capacitor CT1, and an output capacitor COUT1. A secondary side winding voltage, when the drive switch Q1 or the active clamp switch Q2 is on, is held in the tank capacitor CT1, and by superimposing the secondary winding voltage, when the drive switch Q1 or the active clamp switch Q2 is off, on the voltage held in the tank capacitor CT1, the configuration is such that output voltage VOUT equals boosted voltage VBULK times (NS divided by NP).

The invention discloses a three-level current type push-pull bidirectional DC-DC converter, relates to the technical field of power electronics, and is used for realizing bidirectional energy conversion between low voltage and high voltage. The converter comprises a low-voltage side circuit, a high-voltage side circuit, a transmission inductor and a control unit. The low-voltage side circuit is composed of a boost inductor, an active clamping circuit and a push-pull transformer. The high-voltage side circuit adopts a three-level half-bridge structure, and voltage boosting is realized through a voltage-multiplying capacitor; the transmission inductor is used for efficient bidirectional power transmission. And the control unit adopts a PWM + phase shift composite control strategy to accurately adjust the duty ratio, the inter-bridge shift phase ratio and the intra-bridge shift phase ratio, so that the accurate control of the power transmission direction and size is realized. According to the converter, the switching loss is reduced while the conversion efficiency is improved, the system stability is improved, and the converter is suitable for high-efficiency energy transmission application of electric vehicle charging, an energy storage system, a renewable energy source power grid and the like. Through optimization design, the reliability and adaptability of the system can be greatly improved.

An active clamp photoelectric sensing device includes an input terminal, a first output terminal, a current-to-voltage conversion circuit, and an active clamp circuit. The input terminal receives an input current. The first output terminal outputs a first output voltage. The current-to-voltage conversion circuit is coupled between the input terminal and the first output terminal, and is used to discharge and lower potentials of the input terminal and the first output terminal to a first set voltage according to the state of a reset signal, or is used to gradually increase the first output voltage to a second set voltage. The active clamping circuit is coupled to the current-to-voltage conversion circuit, and is used to clamp the upper limit of the first output voltage to the second set voltage.

The utility model relates to a switching power supply circuit and electronic equipment. The circuit comprises a power supply input end, a power supply output end, a transformer comprising a primary winding and a secondary winding, a main power switch unit, an active clamping unit, a clamping driving unit, a voltage dividing unit and a built-in MOS control chip. The main power switch unit is connected with the power supply input end, the primary winding and the voltage division unit, and is switched on when receiving voltage division output of the voltage division unit; the voltage dividing unit is connected with the power supply input end and the built-in MOS control chip, and generates divided voltage output when the built-in MOS control chip is switched on; the clamping driving unit is connected with the built-in MOS control chip and generates a first driving level when the clamping driving unit is switched on and generates a second driving level when the clamping driving unit is switched off, and the active clamping unit is connected with the primary winding and the clamping driving unit, is switched off when receiving the first driving level and is switched on when receiving the second driving level. According to the utility model, the loop loading capability and the voltage stress bearing capability can be improved through a simple circuit design.

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 invention relates to a converter circuit and electronic equipment. The converter circuit comprises an active clamping circuit, a control circuit and a voltage stabilizing circuit, active devices in the active clamping circuit are controlled through the active clamping circuit to realize soft switching, that is, a first switching tube and a second switching tube are controlled to realize soft switching, so that the conduction loss of the first switching tube and the second switching tube is reduced, and the switching efficiency is improved. The problem that large loss is caused when the PFC converter works at high frequency due to the fact that an existing passive clamping circuit cannot achieve soft switching is solved.

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.

The invention belongs to the field of power electronics, and discloses an active clamping circuit and method for inhibiting crosstalk of a silicon carbide MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor), symmetrical dual active clamping driving sub-circuits are adopted, and each sub-circuit responds to a driving signal through a control tube and dynamically manages the on-off state of a clamping tube. When the first silicon carbide MOSFET is conducted to cause crosstalk, the control tube on the turn-off side is cut off to enable the clamping tube to be conducted, the gate-source voltage of the second silicon carbide MOSFET is clamped to negative voltage, and forward misconduction and negative breakdown are avoided; during the turn-off period of the double tubes, displacement current is discharged by a low-impedance path of the clamping tube; when the second silicon carbide MOSFET is conducted, the control tube is turned on to turn off the clamping tube, and the voltage clamping is relieved. The circuit overcomes the defects that gate pole resistance affects the switching speed, passive clamping lacks dynamic response and external signal delay exists, and the switching speed, the system reliability and the control cost are considered while crosstalk peaks are restrained; not only is the high-frequency switching advantage of the silicon carbide MOSFET maintained, but also the safety of the grid electrode is protected through accurate voltage clamping.

Solid-state circuit breakers (SSCBs) have been witnessing an impressive progress with the aid of wide bandgap (WBG) devices such as silicon carbide (SiC) MOSFETs. Along with obtaining high efficiency as the result of low on-state resistance, response times have been gaining remarkable achievements in microseconds range. Not only that, the reported successes in control and gate drivers design and incorporating fault detection / location techniques in SSCBs are promising. A MOV-resistive capacitive switch (MOV-RCS) snubber for solid state circuit breakers addresses the following: 1) the MOV degradation issue in DCCBs is solved, 2) the maximum allowable DC bus voltage on DCCBs is extended. The solid state circuit breaker and an active clamping snubber includes a first circuit including a fault current bypass based solid state breaker for low voltage direct current systems.

The application provides a controller of an active clamp flyback conversion circuit, a power module and an electronic device. After the active clamp flyback conversion circuit operates in a suspended working state, the controller controls the discharge of a resonance capacitor of the active clamp flyback conversion circuit, so that the voltage value of the output voltage of the power circuit is higher than the preset voltage value of the low-voltage protection of the controller, thereby avoiding the restart of the controller due to the low-voltage protection, and improving the stability of the power module and the electronic device in which the active clamp flyback conversion circuit is located. Moreover, when the controller controls the discharge of the resonance capacitor, the output voltage ripple of the active clamp flyback conversion circuit is not increased, and noise from the input power is not introduced.

Provided is a switching module and a process of commutating the switching module. The switching module includes an H-bridge circuit with bidirectional switches and an active clamp with switches that are also arranged as an H-bridge. The process of commutating the switching module includes a sequence of alternating first and second commutation events where timing signals used to control the switches during each commutation event are varied according to closed loop control of the voltage across the energy storage device of the active clamp.

The present invention provides a semiconductor device that can reduce the overall surface area of ​​multiple diode elements in a clamp circuit while satisfying the required element breakdown voltage for each individual diode element. [Solution] The semiconductor device includes a chip 2 having a first main surface 3, a p-type first well region 64 formed on the surface of the first main surface 3, and an active clamp circuit interposed between the drain terminal 15 and the gate control circuit. The active clamp circuit includes a plurality of diode elements DS formed on the surface of the first well region 64 in a diode formation region 8 set on the first main surface 3 and connected in series with each other. The plurality of diode elements DS include two first diode elements DS1 and ten second diode elements DS2 whose distance in the first element direction X1 on the outer circumference is shorter than that of the first diode elements DS1. The two first diodes DS1 are connected to the drain terminal 15 side of the ten second diodes DS2.

An integrated circuit includes a shallow P-type well (SPW) below a surface of a semiconductor substrate and a shallow N-type well (SNW) below the surface. The SPW forms an anode of a diode and the SNW forms a cathode of the diode. The SNW is spaced apart from the SPW by a well space region; and a thin field relief oxide structure lies over the well space region.

The application provides a kind of driver protection function test circuit and test method, the test circuit includes: short-circuit protection function test circuit, gate under-voltage protection function test circuit and high-voltage active clamping protection test circuit, wherein, short-circuit protection function test circuit is tested by double-path voltage division between the collector / drain and emitter / source of the driver to be tested, power emitter / source and emitter / source to apply voltage to carry out short-circuit protection function test;Gate under-voltage protection function test circuit is tested by series voltage division to adjust the power supply voltage of the driver to be tested to carry out gate under-voltage protection function test;High-voltage active clamping protection test circuit carries out active clamping protection test by detecting high-voltage DC power output current. By implementing the application, the protection function test of the driver is realized, and the function retest of the driver under the condition of no structural damage before final shipment is solved.

Switch module for a power electronic switching assembly. A switch module (1) is described. The switch module (1) comprises an H-bridge circuit (2) with four switching assemblies and an active clamp circuit (6) with four controllable semiconductor switches (S5, S6,..., S8). Each switching assembly comprises a pair of controllable semiconductor switches (S1, S2,..., S4 and S9, S10,..., S12) electrically connected in anti-serial. Each switching assembly alternatively can comprise a controllable semiconductor switch and a diode electrically connected in series. The H-bridge circuit (2) comprises first and second AC bridge terminals (AC1, AC2) electrically connectable to a respective coil (4) and first and second DC bridge terminals (DC1, DC2) electrically connectable to a DC current source or to DC bridge terminals of another switch module. The active clamp circuit (6) comprises first and second DC clamp terminals (DC3, DC4) between which a energy storage device (C) is electrically connected. A plurality of switch modules can be electrically connected together to provide a power electronic switching assembly.

In an example embodiment, a method comprising identifying, by a primary-side controlled Universal Serial Bus Power Delivery (USB-PD) alternating current to direct current (AC-DC) converter, a first pulse, wherein the first pulse is received from a pulse transformer. The method further includes determining that a threshold duration of time is satisfied. In response to determining that the threshold duration of time is satisfied, the method includes identifying a second pulse, wherein the second pulse is received from the pulse transformer. The first pulse and the second pulse are used for control of a high-side field effect transistor (FET) and a low-side FET, where the high-side FET is coupled to an active clamp flyback (ACF) circuit and the low-side FET is coupled to a flyback transformer of the USB-PD AC-DC converter. In response to identifying the second pulse, the method further includes controlling operation of the high-side FET or the low-side FET.

The invention belongs to the technical field of elevator falling prevention, and particularly relates to a self-locking anti-falling elevator which comprises a safety tongs mounting plate, main structures are symmetrically clamped and mounted on the end face of the side, close to the gravity, of the safety tongs mounting plate, an anti-falling structure is arranged on the side, close to the gravity, of each main structure, and a cleaning structure is arranged outside the safety tongs mounting plate; when the brake clearance is abnormal (insufficient compensation or excessive compensation trigger), the driving caliper arm is pulled through the steel wire rope, relative clamping is generated between the brake wedge block in the progressive safety caliper and the guide rail, and no matter whether the brake wedge block fails to brake the guide rail or not, the cable always changes the traction wheel to a set angle range, so that the safety of the safety caliper is ensured. And finally, the elastic floating clamping mechanical chain transmission of the brake clamping plate to the guide rail is realized through whether the Z-section rack is meshed with the brake gear or not, and the limitation of a fixed indexing value is avoided.

The invention relates to the technical field of semiconductors, and discloses a GaN HEMT structure with an active clamping absorption circuit, the GaN HEMT structure comprises a base layer substrate, a base layer buffer layer, a base layer GaN layer and a base layer AlGaN layer, and the GaN HEMT structure further comprises a base layer source electrode, drain electrode metal, a base layer grid electrode, a base layer dielectric layer and a connecting dielectric layer; the active clamping absorption part and the GaN HEMT core structure are efficiently integrated, a potential conduction path is optimized, the instantaneous overvoltage peak generated by the drain electrode in a high-frequency switching scene can be quickly responded, overvoltage energy is efficiently absorbed and discharged, a grid electrode or a drain electrode insulation structure is prevented from being broken down by overvoltage, the working stability of the device is remarkably improved, and the reliability of the device is improved. The core problem that a traditional device is prone to being damaged due to overvoltage is solved.

The invention relates to an SEPIC-ZETA bidirectional DC-DC efficient converter based on improved RCD passive absorption and active clamping. The SEPIC-ZETA bidirectional DC-DC efficient converter comprises a bidirectional DC-DC isolation conversion module, a first-stage RCD clamping absorption unit, a second-stage RCD clamping absorption unit, a third-stage RCD clamping absorption unit and an active clamping circuit module. According to the bidirectional DC-DC high-efficiency converter, stress of a switch tube can be effectively clamped when the SEPIC-ZETA works bidirectionally, meanwhile, energy of leakage inductance is absorbed through the corresponding RCD clamping absorption unit and fed back to a bus to be utilized, and the working efficiency and the dynamic performance of the isolation converter are greatly improved. Through efficiency optimization and the working characteristics of the SEPIC-ZETA circuit, the converter can be better suitable for a DC-DC bidirectional circuit, and PWM closed-loop control is used under the condition that the efficiency of the converter is kept, so that the converter can be better applied to more power supply devices such as an energy storage inverter, a UPS, a server power supply and the like.

The invention relates to an active clamping flyback converter and a control method thereof, and belongs to the field of flyback converters. According to the active clamping flyback converter, voltage stabilization of output voltage is achieved through a double-closed-loop control structure composed of a peak current mode loop and a dead time control loop, and the peak current mode loop is used for controlling the conduction time of a main switching tube. And the dead time control loop is used for detecting whether the active clamping flyback converter realizes a soft switching function or not. A double-loop control loop of a peak current mode and a dead time control mode is adopted, the problem that when the active clamping flyback converter is in light load, zero voltage switching is difficult to achieve in the first switching period, and additional loss is caused is solved, the cost of circuit design is effectively reduced, the occupied size is reduced, and the integration level is improved.

The invention relates to a DC-DC converter for transferring energy from a high-voltage network into a low-voltage network. For this purpose, a circuit configuration is used which can be operated either as an active clamp flyback converter or as an active clamp buck converter.

The utility model relates to a bus voltage discharge circuit of a photovoltaic energy storage inverter and a photovoltaic energy storage system. The bus voltage discharge circuit comprises a control power supply, an energy storage unit, a current-limiting voltage-dividing unit, an active clamping unit, a power switch tube and a discharge unit, the control power supply outputs a voltage control signal; the energy storage unit clamps the control end voltage of the power switch tube during starting to control the loop not to be conducted, and releases electric energy to control the power switch tube to be started during shutdown; the current-limiting voltage-dividing unit executes current-limiting operation; the active clamping unit is used for clamping the voltage at the control end of the power switch tube during normal operation; and the discharge unit discharges the voltage on the direct current bus during discharging. According to the utility model, the power switch tube can be controlled to rapidly start and work after shutdown, start loss and conduction maintenance of the discharge loop after shutdown can be avoided, faults caused by start of the discharge loop during normal operation can be avoided, and the system stability is effectively ensured.

The invention discloses an IGBT (Insulated Gate Bipolar Translator) driving control method based on secondary side hardware protection and active clamping, which comprises the following specific steps of: establishing an IGBT digital twin model, and updating junction temperature distribution, saturation voltage drop and theoretical boundaries of a dynamic safe working area under different working conditions in real time through model simulation; in the normal switching process of the IGBT, voltage waveforms and current change rate waveforms in the switching-on and switching-off stages of the IGBT are collected in real time, key parameters are identified, and meanwhile self-adaptive correction is carried out; according to the invention, the conversion from passive protection to active prediction can be realized, the accuracy of protection criteria is greatly improved, the voltage stress and loss of a device are remarkably reduced, false triggering and misjudgment are reduced, the self-diagnosis capability and response speed of a system are improved, the time precision and coordination of protection decisions are ensured, and the reliability of the system is improved. Thermal fatigue and breakdown risks caused by overstress are reduced, so that the service life of the device is prolonged, and the overall reliability and operation efficiency of the power module are improved.

The application discloses a working mode detection method and circuit of an active clamp flyback converter, a main control chip, samples a drain end voltage VDS of a main power tube QL in a current period, detects a first voltage drop time of the main power tube QL after the main power tube QL is turned off, and determines the working mode of the current period of the active clamp flyback converter by judging the sequence of the first voltage drop time and a clamp tube driving time. Furthermore, based on the working mode determination result, the dead time of the active clamp flyback converter is accurately adjusted to be suitable for the detected working mode, the problem of mismatching between the dead time and the working mode is avoided, the main power tube QL of the active clamp flyback converter can keep realizing soft switching in a full load range, the switching loss of the active clamp flyback converter is greatly reduced, and the efficiency of the converter is improved.

This invention relates to the field of clamping control, and more particularly to an active voltage overshoot clamping system for battery testing equipment. The invention comprises a clamper, a feature memory, a filter, an interference analyzer, a predictor, and a clamping controller. It uses prior data—including the test step execution sequence, time-domain mapped overshoot characteristics, and the attribute characteristics of the tested battery—to filter out overshoot step combinations and construct a drift feature pool specific to each combination. Subsequently, when the test equipment pre-executes the overshoot step combination, the overshoot occurrence is predicted, and a clamping optimization strategy is determined based on the adaptability of the drift feature pool, adjusting the duty cycle upper limit in advance. This invention utilizes prior data to summarize overshoot step combinations and considers the differences in the attributes of the tested battery to construct a drift feature pool. This allows the system to perform clamping control adaptably to the attributes of the tested battery under different overshoot step combinations, improving the accuracy and reliability of overshoot voltage suppression.

This invention belongs to the field of power electrical technology and relates to a wide voltage range clamped boost LLC resonant converter, comprising: an input DC bus voltage unit, an active clamped boost unit, an inverter bridge unit, an LLC resonant tank unit, a transformer T, and a rectification and filtering unit; the active clamped boost unit includes a first feed inductor, a second feed inductor, a clamping capacitor, a third switch S3, and a fourth switch S4; the LLC resonant tank unit includes a resonant inductor and a resonant capacitor connected in series, and a magnetizing inductor of the transformer T; the rectification and filtering unit includes a first rectifier diode, a second rectifier diode, and a filter capacitor C. o Load R L This invention solves the technical problem in the prior art that traditional LLC converters have a limited gain adjustment range and cannot simultaneously meet high boost requirements.

The utility model provides a forward active clamping driving system. A control circuit in the forward active clamping driving system comprises a main switch unit, an active clamping switch unit and an active clamping capacitor. The main control chip comprises a first pin and a plurality of second pins. The control end of the active clamping switch unit is electrically connected with the plurality of second pins through the clamping control circuit, the first end of the active clamping switch unit is electrically connected with the second polar plate of the active clamping capacitor, and the second end of the active clamping switch unit is electrically connected with the grounding end; and the clamping control circuit is used for controlling the active clamping switch unit to be switched on when the forward active clamping driving system is in a shutdown state. Thus, through the clamping control circuit, the active clamping switch unit can still be conducted when the system is in the shutdown state, and the situation that the active clamping switch unit is continuously turned off when the system is in the shutdown state, consequently, an active clamping capacitor is continuously charged, and the reliability of the main switch unit or the active clamping switch unit is affected is avoided.

The invention provides a high-precision output voltage sampling system of a primary side feedback active clamping flyback converter, input signals are a main switch tube switching signal and an auxiliary winding feedback voltage of the primary side feedback active clamping flyback converter, and the high-precision output voltage sampling system mainly comprises a slope generation module, a sampling time judgment module and an output voltage acquisition module; the output signal is a sampling voltage value, and the sampling voltage value is transmitted to the control loop, thereby achieving the closed-loop control of the converter. The slope generation module generates a voltage signal in direct proportion to the change slope of the feedback voltage of the auxiliary winding; the sampling time judgment module determines an output voltage sampling time based on the voltage signal representing the slope; and the output voltage acquisition module acquires an auxiliary winding feedback voltage at an output voltage sampling moment, and transmits the auxiliary winding feedback voltage as an output voltage value to the control loop for closed-loop control. According to the invention, high-precision output voltage sampling of the primary side feedback active clamping flyback converter can be realized.

The invention relates to an active clamping forward topology synchronous rectification driving circuit. The circuit comprises a power transformer, a primary switch tube V1 and an active clamping branch. The primary switch tube V1 is used for converting input direct-current electric energy into high-frequency alternating-current electric energy and transmitting the high-frequency alternating-current electric energy to the secondary through the power transformer; the active clamping branch comprises a clamping switch tube V2 and a clamping capacitor CCLAMP which are connected in series; and the active clamping branch is used for realizing magnetic reset of the power transformer and reducing the voltage stress of the primary switching tube V1. According to the invention, a synchronous rectification driving signal source does not need to be additionally designed, the driving signals of the primary switch tube and the clamping tube of the active clamping forward topology can be directly adopted, the secondary synchronous rectification switch tube of the converter can be driven after isolation and processing, and the design of a signal link is simplified. The direct connection risk of a synchronous rectifier tube in a traditional transformer self-driving scheme can be solved, meanwhile, the driving dead zone is adjustable, and the power conversion efficiency of a converter product is effectively improved.