142 results about "Active clamp" patented technology

An active clamp flyback converter with safe operation is discussed. The active clamp flyback converter has a main power switch and an auxiliary switch integrated at a same IC chip. The active clamp flyback converter enables a first charge path from the power supply voltage to a floating capacitor when the main power switch is turned on. The first charge path is disabled and a second charge path from a second pin of the IC chip to the floating capacitor is enabled when a voltage at the second pin is higher than a reference voltage.

The invention discloses a multi-tube parallel power device phase shift type current sharing and crosstalk suppression drive circuit which is composed of a crosstalk suppression unit, a current balancing unit, a control response unit and a function switching unit. Wherein the crosstalk suppression unit generates a control signal for suppressing the crosstalk voltage of the parallel power device and shields the interference of the current balancing unit; the current balancing unit generates a control signal for balancing the dynamic current of the parallel power device and shields the interference of the crosstalk suppression unit; the control response unit is used for realizing crosstalk active clamping or current active equalization; and the mode switching unit realizes automatic switching of a crosstalk suppression function or a current equalization function according to configuration. Parallel device grid driving signal feedback is introduced, crosstalk voltage active clamping and dynamic current active balancing are achieved through a logic circuit, and the parallel expansibility is high; an exclusive-OR gate is adopted to accurately identify synchronous or asynchronous information of driving signals of the parallel devices, and various different gate sequential modes in parallel application of the hybrid devices can be compatible.

A load driver includes an active clamping circuit coupled between gate and source terminals of a power stage. The active clamping circuit serves to either pass through a gate drive voltage (provided by a gate driver) to the power stage in a PWM mode or to actively clamp the voltage between gate and source terminals of the power stage to enable fast decay recirculation in fast decay mode (when the load driver is configured for active clamping). A semi-active recirculation driver is coupled between ground and the output of the power stage. The semi-active recirculation driver serves to either provide a low impedance recirculation path in the PWM mode or to passively clamp the output voltage to provide for a fast decay recirculation path in fast decay mode (when the load driver is configured for passive clamping).

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.

The invention relates to the technical field of power electronics, and discloses a dynamic regulation and control method and system for an active clamping three-level converter adapting to working condition changes, and the method comprises the steps: calculating the loss sample data of each power device in different modulation modes through obtaining the historical data of characteristic parameters under different working conditions; calculating the junction temperature of the power device based on the loss in the hybrid modulation mode; with the minimum junction temperature distribution imbalance degree as a target, calculating a hybrid modulation coefficient, and constructing a neural network model; after operation parameters of a power device are collected in real time, the optimal modulation coefficient is obtained based on the model, the modulation mode of the converter is dynamically adjusted, and loss distribution is optimized. According to the method, the loss distribution characteristic and efficiency of the converter under all working conditions can be improved, and the loss balance performance is optimized.

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.

In a switch system, a voltage clamping element is connected to a semiconductor switch in parallel. An active clamping circuit is connected between a control terminal and a first main terminal of the semiconductor switch. The active clamping circuit includes a first diode, a second diode, and a control switch. A second anode of the second diode is connected to a first anode of the first diode. The control switch is connected between the first anode of the first diode and the control terminal of the semiconductor switch. A second control unit controls the control switch. A breakdown voltage of the first diode is smaller than a clamp voltage of the voltage clamping element.

The present invention relates to the technical field of roller processing, and specifically to a device for repairing worn rollers, comprising a machine tool, a rotating motor, an active clamp, a passive clamp, a protective half-cylinder, an upper protective cylinder, and a lower protective cylinder; and an automatic switching repair device, wherein the automatic switching repair device is disposed on a side of the machine tool near the protective half-cylinder. The present invention utilizes the automatic switching repair device to provide a plurality of repair stands distributed in a circular array for automatic switching, thereby achieving the effect of performing multiple repairs on the rollers. Multiple repair tasks can be completed without the rollers having to be transported across multiple machine tools, further improving work efficiency during roller maintenance. The protective cylinder, the lower protective cylinder, and the protective half-cylinder are combined to form a complete cylindrical shape, thereby achieving the effect of providing a closed protection for the roller clamped between the active clamp and the passive clamp, thereby preventing problems such as debris or water splashing during roller repair work such as grinding or cleaning.

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 present invention discloses a constant voltage control system for a primary side feedback active clamp flyback converter, which includes a sampling module, an auxiliary switch tube conduction time calculation module, a PID control module, and a switch tube control module; the sampling module samples the auxiliary winding feedback voltage at the moment when both the output diode and the auxiliary switch tube are conducting, and outputs the feedback voltage to the PID control module; the PID control module outputs a peak current target value to the auxiliary switch tube conduction time calculation module and the switch tube control module; the auxiliary switch tube conduction time calculation module designs and outputs the conduction time control parameter of the auxiliary switch tube to the switch tube control module through the slopes of different charging stages after the main switch tube is turned off; the input of the switch tube control module is the conduction time control parameter of the auxiliary switch tube and the peak current target value, and it outputs the duty cycle control signals for the main switch tube and the auxiliary switch tube to switch. The present invention solves the sampling problem of constant voltage control in the CCM mode of the active clamp flyback converter.

A power supply comprises a transformer having a primary winding, a first switch coupled to the primary winding and to a voltage input, an active clamp circuit coupled in parallel with the primary winding, and a clamp switch control coupled to the active clamp circuit. The power supply further comprises a bootstrap circuit coupled to the clamp switch control and having a bootstrap voltage storage device coupled to the clamp switch control. A charging circuit has a resistor network configured to generate a charge voltage in response to an input voltage supplied by the primary winding. A charge voltage storage device is configured to store at least a portion of the charge voltage during the first portion of the switching cycle and to supply the at least a portion of the charge voltage to the bootstrap voltage storage device during a second portion of the switching cycle.

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.

The present invention discloses a circuit and a control method for preventing a semiconductor switch device from being turned on by mistake. The circuit includes: an active clamping circuit, a control circuit, a power amplifier circuit and an interference suppression circuit; the control circuit is coupled to the input end of the power amplifier circuit; the output end of the power amplifier circuit is coupled to the gate of the semiconductor switch device; the first end of the active clamping circuit is connected to the first end of the semiconductor switch device, and the second end is connected to the input end of the power amplifier circuit. The active clamping circuit is configured to act within a preset time period from the moment when the voltage between the first end and the second end of the semiconductor switch device is greater than the preset voltage; the interference suppression circuit includes a controllable switch; the controllable switch is configured to be turned on after the action of the active clamping circuit is completed, so that the potential of the input end of the power amplifier circuit is clamped to a fixed potential. The present invention can effectively prevent the active clamping circuit from causing the switch device to be turned on by mistake due to the increase of the energy injected into the gate of the switch device.

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.

A lithium ion battery SOC active equalization circuit comprises an n-winding flyback converter, (n-1) bridging capacitors and n lithium ion batteries, and the n-winding flyback converter comprises two power switches S1 and S2, an input capacitor Cin, an active clamping capacitor Cs, an excitation inductor Lm and a transformer T; and a first output diode D1 and a first output capacitor C1. A second output diode D2 and a second output capacitor C2; ,...; an nth output diode Dn; and an nth output capacitor Cn. On the basis of transformer type equalization, a multi-winding transformer equalization topological structure is adopted, and the SOC equalization of the series battery pack is realized by adding bridging capacitors among windings. Compared with a traditional multi-winding transformer equalization structure, equalization of the battery pack is achieved only through two switches, the control difficulty and cost of the circuit are reduced, the problem of terminal voltage imbalance caused by the cross adjustment rate during multi-winding output of the transformer is solved, voltage deviation is effectively reduced, and the battery equalization precision is improved.

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.

The invention discloses an active clamping absorption circuit parameter design method, which is applied to a full-wave rectification circuit of a phase-shifted full-bridge converter, is used for absorbing leakage inductance and voltage spike and oscillation generated by parasitic capacitance resonance of a rectification tube, and comprises the following steps: acquiring output filter inductance current, calculating the primary side resonant inductance peak current of the transformer according to the filter inductance current; calculating the charging time of the clamping capacitor; the absorption circuit parameters are calculated according to the relation between the absorption circuit parameters and the transformer primary side resonant inductance current peak value and the clamping capacitor charging time; according to the active clamping absorption circuit parameter design method, the parameter design process can be simplified, and voltage spike and oscillation can be effectively suppressed.

To achieve both a power source reverse connection protection function and an active clamp function.SOLUTION: A semiconductor device 1 includes a power source terminal T1, an output terminal T2, and a ground terminal T4, an internal output node OUT_R that is electrically connected to the output terminal T2, an internal ground node GND_INT that is electrically connected to the ground terminal T4, an output transistor 10 connected between the power source terminal T1 and the output terminal T2, a gate driver 31 that drives the output transistor 10, a reverse connection protection circuit 110 that turns on the output transistor 10 without depending on the gate driver 31 when the ground terminal T4 has a higher potential than the power source terminal T1, and a through-rate control circuit 130 that raises the off-time through rate of the gate driver 31 when the internal output node OUT_R has a lower potential than the internal ground node GND_INT.SELECTED DRAWING: Figure 7

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.