1118 results about "Filter capacitor" patented technology

The invention relates to the technical field of semiconductor laser power supplies, in particular to a semiconductor laser power supply control circuit based on linear constant current and a method thereof. According to the technical scheme, the circuit comprises a voltage follower module, a linear constant-current driving module, a power switch module, a pulse control module, a sampling feedback module and a follow current protection unit. The in-phase input end of an operational amplifier OPA320 of the voltage follower module is connected with external reference voltage # imgabs0 #, the inverted input end of the operational amplifier OPA320 is grounded through a first resistor R1 and connected with the output end through a second resistor R2, and a filter capacitor C1 is connected to the two ends of the second resistor R2 in parallel. Through a linear constant current control and pulse cooperation mechanism, the current stability and the dynamic response speed of the semiconductor laser under the wide-range and high-frequency working condition are remarkably improved, and it is guaranteed that the laser output power is accurate and reliable.

The invention discloses a single-load wireless power transmission system with single transmitting and double receiving coils and a method thereof. The system comprises a direct-current power supply, a high-frequency inverter, a transmitting end compensation topology module, a transmitting coil module, two receiving coil modules, two receiving end compensation topology modules, a rectifier module, a filter capacitor and a system load module. The topological structure adopts S-LC and S-LCC compensation topology, and a topological structure parameter optimization method is provided, so that the anti-offset characteristic of the system is effectively improved. The optimized system can realize the stability of the output power of the system under the working conditions of offset and load change within a certain range. According to the system, the cost of the system is reduced, the high anti-offset capability can be achieved, the output power is stable, and the overall efficiency of the system is improved.

The present invention relates to a magnetic resonance system and a gradient amplifier filter for a magnetic resonance system. The filter includes a plurality of non-magnetic core inductors and a printed circuit board having a multilayer structure, a plurality of filter capacitors being formed in a plurality of regions of the printed circuit board, respectively, wherein each non-magnetic core inductor is provided on the printed circuit board and spanning two of the plurality of filter capacitors.

The invention discloses an isolation type split-phase inverter circuit and a control method thereof. The isolation type split-phase inverter circuit comprises an isolation DC / DC module circuit and a power frequency rectification module circuit. The isolation DC / DC module circuit comprises an input-side full bridge, a three-end transformer and two output-side circuits, an input-side winding of the three-end transformer is connected with a midpoint of a bridge arm of the input-side full bridge, and the input-side full bridge is connected with a filter capacitor C1 in parallel; two output side windings of the three-end transformer are respectively connected with corresponding output circuits through a resonance network circuit, the two output circuits are connected to a power frequency rectification module circuit through filter capacitors C4 and C5, and the negative electrode of the first output circuit and the positive electrode of the second output circuit are connected to form an interface N; the power frequency rectification module circuit comprises a rectification full-bridge circuit, and an interface L1 and an interface L2 are obtained after rectification. Through cooperative control of direct transmission of integrated topology and voltage signals, a complex parameter matching algorithm is not needed, breakthrough in structure simplification, energy conversion efficiency, control convenience, cost control and safety is achieved, and the method is suitable for various power conversion scenes.

The invention discloses a control method and device for switching grid connection to grid disconnection of an energy storage system. The control method comprises the following steps: acquiring a phase voltage and a bus voltage on a line when the energy storage system is controlled to be switched to an off-grid state; determining the maximum open-loop duty ratio according to the phase voltage and the bus voltage; within preset time, the energy storage system is controlled to be in an open-loop driving state, and the duty ratio of a driving signal sent to the energy storage inverter is controlled to be monotonically decreased from the maximum open-loop duty ratio, so that the voltage output by the energy storage inverter is controlled to be gradually decreased to be close to zero, therefore, the voltage output by the energy storage inverter and the voltage on the filter capacitor connected with the output side of the energy storage inverter are not opposite in phase, the oscillation of the output voltage is avoided, the impact current of the output port is suppressed, and the stable operation of the energy storage inverter of the energy storage system is ensured.

The invention discloses a common-mode electromagnetic interference modeling and suppression method for a matrix converter, and the method comprehensively considers high-frequency parameters and topological characteristics, builds a conduction CM EMI equivalent circuit model of the matrix converter, completes the impedance network fitting of key elements and the extraction of high-frequency parasitic parameters, and achieves the modeling and suppression of the common-mode electromagnetic interference of the matrix converter. The precision of the CM EMI model of the matrix converter is improved, and the analysis of the CM EMI characteristics of the matrix converter is simplified. According to the common-mode electromagnetic interference suppression method for the matrix converter, CM EMI characteristics of the matrix converter are analyzed, a low-attenuation loop in the converter is constructed by adopting a method of combining a neutral line leading-back type structure and increasing output filter capacitor neutral-point-to-ground parasitic capacitance, the propagation proportion of noise in a linear impedance stabilization network measurement branch is reduced, and the measurement accuracy of the common-mode electromagnetic interference suppression method for the matrix converter is improved. And effective suppression of low-cost CM EMI noise is realized on the premise of not depending on an input EMI filter.

The utility model discloses an anti-thunder filtering electric connector, which comprises a metal shell, an input end contact element, a filtering capacitor, an output end lead, a transient suppression diode and a printed board, and is characterized in that the filtering capacitor is a plate-type capacitor which is arranged in the metal shell; the plurality of input end contacts respectively pass through a plurality of inner electrode through holes of the plate-type capacitor and a plurality of corresponding through holes on the printed board, the plurality of transient suppression diodes are respectively installed on the printed board, and one ends of the transient suppression diodes are respectively in conductive connection with the plurality of input end contacts. The other ends of the plurality of transient suppression diodes are respectively and conductively connected with the inner wall of the metal shell, and the inner ends of the plurality of input end contacts are respectively and conductively connected with the inner ends of the plurality of output end leads. The utility model has the functions of filtering, lightning protection and electric connection at the same time, the product integration level is very high, the volume and the weight are reduced, a lightning protection circuit module does not need to be added in a post-stage circuit module during application, the design and the production of the whole machine are facilitated, and the production efficiency of the whole machine is improved.

The invention relates to a converter soft start method based on mode seamless switching, which belongs to the technical field of converter soft start, and comprises the following steps: a converter adopts a network following / network construction hybrid control structure; after the converter receives a starting instruction, voltage and frequency are automatically constructed in a network construction control mode, and a filter capacitor is pre-charged; performing amplitude and phase angle pre-synchronization on the voltage of the output port of the converter and the voltage of the power grid based on a pre-synchronization strategy; and switching the converter from a network construction control mode to a network following control mode to complete soft start. According to the method, the pre-charging requirement of the alternating current capacitor is met, and soft-start smooth grid-connected operation of the converter is realized through a pre-synchronization strategy.

The invention provides a detection circuit, a battery pack and a battery management system. The detection circuit is used for detecting a connection circuit of a first battery in a plurality of batteries connected in series. The detection circuit comprises a self-checking resistor; the equalization circuit comprises an equalization switch, and the equalization circuit is connected in series with the first battery through a self-check resistor; the filter circuit comprises a filter capacitor, and the filter circuit is connected with the equalization circuit in parallel; the sampling chip is connected with the two ends of the filter capacitor, the sampling chip, the filter circuit and the self-checking resistor jointly form a sampling circuit of the first battery, the sampling chip is used for determining whether the sampling circuit of the first battery fails or not according to a first voltage and a second voltage, the first voltage is the voltage on the filter capacitor when the equalization switch is switched off, and the second voltage is the voltage on the filter capacitor when the equalization switch is switched off; and the second voltage is the voltage on the filter capacitor when the equalization switch is closed. The detection circuit reduces the diagnosis cost and the overall size.

A fault suppression control method based on a capacitive energy storage system comprises the steps that a DC / DC converter of the capacitive energy storage system is constructed, a voltage and current double-closed-loop control structure of the capacitive energy storage system in a charging mode and a discharging mode is constructed based on the DC / DC converter, and the voltage of an energy storage capacitor or a filter capacitor serves as an outer loop control variable; the current of the energy storage inductor is used as an inner loop control variable, turn-on and turn-off signals of a switching device are output through PWM modulation, and finally fault suppression control is achieved after current-limiting control parameter optimization. Energy absorption and release between the ship power system and the energy storage capacitor are realized by adopting the bidirectional DC / DC converter, fault current suppression during a fault is realized, meanwhile, the requirement on a current limiting reactor is reduced, the cost of system elements is reduced, and the influence of reactor installation on the system is avoided.

The invention relates to an internal serial metallized film, a preparation method, a filter capacitor and a base film, the base film is made of a blending material of polyethylene glycol terephthalate and polyethylene naphthalate according to a mass ratio of 2: 3, and the thickness of the base film is 8-12 [mu] m; the multi-layer metallization layer is arranged on the base film and comprises a first metal layer, a buffer layer and a second metal layer, the buffer layer is located between the first metal layer and the second metal layer, the patterned structure forms a plurality of conductive units which are connected in series on the multi-layer metallization layer, each conductive unit is in a regular hexagon shape, and the first metal layer is arranged on the first metal layer. The side length of the conductive units is 3-6mm, and an isolation belt with the width of 0.3-0.8 mm is arranged between the adjacent conductive units. According to the invention, a plurality of key performance indexes such as high-frequency filtering performance, voltage endurance capability, oxidation resistance, structural stability, light transmission and the like are optimized and improved.

The single-phase bidirectional single-stage isolation matrix converter comprises a pre-stage circuit and a post-stage circuit, and the pre-stage circuit comprises an LC filter on the power grid side, a pre-stage single-phase matrix conversion circuit and an LLC resonance circuit with a high-frequency transformer; the post-stage circuit comprises a post-stage conversion circuit and an output filter capacitor; the front-stage single-phase matrix conversion circuit comprises four bidirectional switch assemblies of a full-bridge structure. Each bidirectional switch assembly comprises two unidirectional controllable MOS tubes which are reversely connected in series, one end of each bidirectional switch assembly is connected to an L line or an N line of a power grid, and the other end of each bidirectional switch assembly is connected to the LLC resonance circuit. The rear-stage conversion circuit comprises a bidirectional MOS (Metal Oxide Semiconductor) tube bridge circuit and three high-frequency transformer secondary windings which are in triangular connection or star connection; and two end points of each secondary winding are respectively connected to the upper MOS tube and the lower MOS tube of the corresponding bridge arm and then are connected to output positive and negative ends. The converter has the advantages of high power density, low current harmonic, high power factor and the like, and is small in size, strong in anti-interference capability, wide in buck-boost range, and safe and reliable in commutation.

The invention relates to the technical field of Internet of Things, in particular to a circuit for simultaneously converting UART (Universal Asynchronous Receiver / Transmitter) to multi-path different level communication, which comprises a double-USB input module, a power supply processing module, a USB-UART core conversion module and a multi-path level conversion module, the double-USB input module comprises an MINI-USB interface J6 and a USB-B interface J8, VBUS pins of the two interfaces are connected in parallel through a Schottky diode and then output to the power supply processing module, and data differential pair pins are connected in parallel and then connected to the USB-UART core conversion module; and the power supply processing module comprises an LDO (Low Dropout Regulator) voltage stabilizing chip and a filter capacitor, and is used for converting 5V voltage output by the double-USB input module into 3.3 V stable voltage. The circuit design that the UART is connected with various different levels for communication is adopted, the tool integration technology is achieved, the design that the two USB ports are connected in parallel is adopted, the compatibility of the USB data line can be effectively improved, the demands of customers are met, and the technical difficulty that one UART bus is connected with multiple USB ports is broken through.

A power converter, power converter controller, and method of controlling a power converter are described. The power converter includes: a half bridge or full bridge switch network; an LLC resonant tank electrically coupled to the switch network; a rectifier circuit electrically coupled to a filter capacitor configured to provide a DC output voltage; a transformer inductively coupling the rectifier circuit to the LLC resonant tank; and a controller configured to determine a reference voltage to which the DC output voltage is regulated, and adjust a switching frequency of the switch network based on a difference between the DC output voltage and the reference voltage. The controller is configured to determine the reference voltage based on input voltage and / or output current feedback for the power converter and / or determine a variable switching frequency or a variable switching period for the switch network based on input voltage magnitude and output current magnitude.

The invention discloses a frequency quasi-independent controllable double-frequency electrically small rectification circuit, and belongs to the field of radio frequency energy collection. The rectifying circuit comprises a double-frequency matching network, a blocking capacitor, two Schottky diodes, a filter capacitor and a resistive load. The dual-frequency matching network is composed of a capacitor, an inductor and a microstrip line and used for achieving impedance matching of two working frequency points and achieving quasi-independent regulation and control of the positions of the two frequency points by adjusting the value of the inductor and the length of the microstrip line. And the microstrip line is bent for five times so as to realize the miniaturization of the overall structure of the circuit. The blocking capacitor is used for blocking a direct current component and avoiding energy feedback; the two Schottky diodes are used for converting a radio frequency signal into direct current energy; the filter capacitor is used for improving the smoothness of output direct current energy and improving the energy conversion efficiency. The device is compact in structure, adjustable in frequency point position and suitable for a dual-band radio frequency energy collection scene.

A bidirectional AC / DC conversion module based on an IGBT discrete device comprises a capacitor filter plate, an IGBT plate and a bottom plate which are arranged in parallel and fixedly connected, distances are reserved between the capacitor filter plate and the IGBT plate and between the IGBT plate and the bottom plate, the capacitor filter plate is provided with a capacitor assembly, and the IGBT plate is provided with an IGBT module. Two groups of first filter capacitors in the capacitor assembly are respectively arranged at two opposite edges of the capacitor filter plate, so that the distance between the two groups of first filter capacitors is reduced, and heat dissipation is facilitated; all the electrolytic capacitors in the capacitor assembly are located in the middle of the capacitor filtering plate, the electrolytic capacitors are arranged at equal intervals, and heat dissipation air channels are reserved, so that heat dissipation is smooth, and normal operation of all devices is guaranteed.

The invention belongs to the field of power electronics, relates to the technical field of inverter design, and provides a silicon carbide MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor)-based high-switching-frequency inverter which comprises a parallel S C inverter, a direct-current bus capacitor and a DSP (Digital Signal Processor) controller. The parallel Si C inverter comprises a plurality of parallel bidirectional bridge arm inverters, and the output end of each bidirectional bridge arm inverter is connected with a Hall sensor CT. And one end of the direct current bus capacitor is connected with the positive terminal of the parallel Si C inverter, and the other end of the direct current bus capacitor is connected with the negative terminal of the parallel Si C inverter. The DSP controller comprises a plurality of driving circuits, a current sampling circuit and a PWM control signal conversion circuit. According to the inverter, under the condition that the power frequency of the inverter is ensured and the quality of the output waveform is not influenced, the volume and the weight of the filter inductor and the filter capacitor are greatly reduced, and the requirement of product weight limitation is met.

The invention relates to a module power supply and a power supply system, and the module power supply is constructed on a four-layer PCB, and comprises an input filtering module; the power conversion module comprises a primary winding with a tap and a primary main control chip; a power tube is arranged in the primary main control chip, and pulse voltage applied to the primary winding and energy transmitted to the secondary side are adjusted by controlling the on-off state of the power tube; after the power tube is turned off, the tap of the primary winding is used for extracting part of the primary winding to form an auxiliary winding to supply power to the primary main control chip; the secondary rectification and output filtering module comprises a secondary winding, a rectifier tube and a filter capacitor, and is used for rectifying and filtering the alternating current secondarily output by the transformer to generate direct current output; the feedback control module collects and processes the output voltage to generate a correction error signal and is used for feeding back the switching time of the power tube; and the auxiliary power supply module is used for rectifying, filtering and stabilizing the auxiliary power supply voltage output by the auxiliary winding so as to supply power to the primary main control chip.

The invention discloses an LLCL filter design method, and relates to the technical field of power electronics. The method comprises the following steps: acquiring an initial filter capacitance, an initial inverter side filter inductance, a power grid side filter inductance and a target frequency; calculating filtering branch inductance based on the filtering capacitance and the target frequency; calculating a positive harmonic peak frequency based on the filter capacitor, the inverter side filter inductor, the power grid side filter inductor and the filter branch inductor; calculating damping resistance, damping inductance and damping capacitance based on the positive harmonic peak frequency, the filter capacitance, the resonant frequency value constraint, the first value range constraint and the second value range constraint of the quality factor; and when the target parameter does not meet the grid-connected current harmonic standard, updating the filter capacitor and / or the inverter side filter inductance, and skipping to the step of calculating the filter branch inductance based on the filter capacitor and the target frequency so as to carry out iteration until the grid-connected current harmonic standard is met. According to the embodiment of the invention, the design optimization of the parameter value of the filter element in the LLCL filter is realized.

The invention relates to a single-stage AC-DC converter and a control circuit. The single-stage AC-DC converter comprises a filter, an input rectifier, a filter capacitor Cin, a first switch bridge arm, a second switch bridge arm, a capacitor Cb, an inductor Lb, a resonant cavity formed by a resonant inductor Lr and a resonant capacitor Cr, a transformer T, an output rectifier and an output capacitor Co. According to the invention, a traditional two-stage AC-DC converter and a control circuit are simplified. Compared with a single-stage AC-DC converter in the prior art, the problem that the current of a resonant cavity is too large can be solved only by adding one inductor, meanwhile, the control strategy is simple, the frequency range conversion of a switching tube is small, and soft switching of the switching tube is easy to achieve, so that high efficiency is easy to obtain, input current can be corrected to achieve a high power factor, and the power factor is high. And the output voltage ripple is small, and the method has remarkable engineering application value and market prospect.

The invention belongs to the technical field of three-phase alternating current / direct current converters, and particularly relates to a SWISS rectifier control method and system for achieving phase compensation and reducing input current harmonics, and the method comprises the steps: obtaining power grid synchronization information through sampling three-phase power grid voltage in real time and carrying out phase locking and coordinate transformation; a d-axis current reference value is generated by adopting a single PI control loop, and a q-axis compensation current is calculated in combination with feedforward compensation based on filter capacitor parameters; an input current reference value is generated through reverse Park conversion and voltage sorting, and after the direct current side inductive current is subjected to power frequency period synchronous moving average filtering, the direct current side inductive current is directly compared with the current reference value to generate a PWM driving signal. The system only needs to collect direct-current side inductance and three-phase power grid voltage, and a grid-side current sensor is not needed. According to the invention, the control structure is simplified, the power factor is improved, and input current harmonics and hardware cost are reduced.

The invention discloses a three-phase wireless electric energy and signal reverse cooperative transmission system and a parameter design method thereof. The system comprises a direct-current power supply, a three-phase high-frequency inverter circuit, a three-phase primary side compensation capacitor, a three-phase secondary side compensation capacitor, a three-phase primary and secondary side magnetic coupling coil, a signal transmission channel network, a signal modulation-demodulation circuit network, an encoder, a decoder, a three-phase rectification filter circuit, a filter capacitor and a load resistor. The signal transmission channel networks respectively comprise three signal injection networks and three signal separation transmission channel networks; each signal injection network comprises a secondary side signal injection transformer, a secondary side injection signal resonant capacitor and a discharge resistor; and each signal separation transmission channel network comprises a primary side signal pickup transformer, an extraction signal resonant capacitor, a wave blocking network inductor, a wave blocking network capacitor and a sampling resistor. According to the invention, three-phase wireless energy and information parallel reverse transmission is realized, and the signal transmission rate is effectively improved while stable and efficient electric energy transmission is ensured.

A single-stage isolation type three-phase Cuk rectification circuit comprises a three-phase AC power supply in star connection, three bridgeless isolation type Cuk rectification circuit bridge arm modules with the same structure, an output filter capacitor Co and a load RL. The input ends of the three bridgeless isolation type Cuk rectifier circuit bridge arm modules are line voltages of a three-phase alternating current power supply, and are uab, ubc and uca respectively; the output ends of the three bridgeless isolation type Cuk rectifier circuit bridge arm modules are connected in parallel, and the parallel output ends are connected in parallel with the output filter capacitor Co; and the output filter capacitor Co is connected in parallel with the load RL. The converter has the functions of buck-boost output, power factor correction and electrical isolation, meanwhile, each Cuk rectification circuit bridge arm is of a bridgeless structure, input and output current is continuous, the power factor is high, efficiency is high, positive wide-range output voltage is achieved, the current stress of a switching device is small, and the converter has rich application scenes.

The invention relates to the technical field of wireless charging, and particularly discloses a wireless electric energy transmission system for multi-split charging of an electric bicycle, which comprises a direct-current voltage source UD, a high-frequency inverter H, an alternating-current switch Si, a transmitting side LCC compensation network, a magnetic coupler, a receiving side LCC compensation network, a rectifier Di, a filter capacitor CFi and a battery load RBi, an alternating current switch Si, the transmitting side LCC compensation network, the magnetic coupler, the receiving side LCC compensation network, the rectifier Di, the filter capacitor CFi and the battery load RBi form an electric energy output channel, the output channel is connected with the high-frequency inverter H, and the output end of the rectifier Di supplies power to the battery load RBi through the filter capacitor CFi. The beneficial effects of the invention are that the system can achieve the automatic switching of a plurality of output channels from a constant current mode to a constant voltage mode under the condition of no detection and no special control circuit, improves the utilization rate of an inverter, saves an open circuit protection circuit, reduces the cost, and is suitable for the one-to-many charging application of electric bicycles of different specifications.

The invention provides a parameter design method for a multi-voltage rectification LCC converter, and the method comprises the steps: building a voltage precise mathematical model of a resonant cavity parallel capacitor through employing a fundamental wave equivalent method based on the condition that output capacitors of the multi-voltage rectification LCC converter and a multi-voltage rectifier participate in resonance; the gain of the voltage-multiplying LCC resonant converter is modeled through a voltage accurate mathematical model of a resonant cavity shunt capacitor; determining the number of rectifier bridges, the turn ratio of a transformer and the capacitance value of a rectification voltage-multiplying capacitor according to the voltage of the parallel capacitor of the resonant cavity and the gain of the voltage-multiplying LCC resonant converter; and determining values of the resonant cavity series-parallel capacitor and the resonant cavity inductor according to the capacitance value of the rectification voltage-multiplying capacitor. According to the method, analysis and calculation of the output filter capacitance are incorporated into parameter design of accurate modeling, a scheme for selecting the number of the voltage doubling rectifier bridges is given, and the size can be reduced and economic benefits can be increased under the condition that working condition requirements are met.

The invention discloses a current source inverter power supply permanent magnet synchronous motor system control method and system, and belongs to the field of permanent magnet synchronous motor control. Establishing a discrete state space equation of the dq-axis current source inverter power supply type permanent magnet synchronous motor system by using state variable information of a control system of the permanent magnet synchronous motor system at a sampling k moment; designing a filter capacitor voltage estimator, obtaining a filter capacitor voltage estimated value, designing a feedback-integral controller, and solving a dq-axis inverter output current control instruction; three optimal current vectors closest to an inverter output current control instruction are selected, the optimal current vectors and the optimal duty ratio are calculated, an optimal switching pulse sequence is output to act on a switching tube of the current source inverter, and current control over the current source inverter power supply permanent magnet synchronous motor system is achieved. The method is high in control precision and high in dynamic response speed.

The invention discloses an optical module packaging structure and an optical module. The optical module packaging structure comprises a printed circuit board; a plurality of mounting grooves are formed in the end part of the overlapped part of the bottom plate and the printed circuit board at intervals; the number of the EML assemblies is equal to that of the mounting grooves, the EML assemblies are in one-to-one correspondence with the mounting grooves, and the EML assemblies comprise chip packaging substrates which are located in the mounting grooves and connected with the bottom plate; the EML laser chip is located in the mounting groove and connected with the chip packaging substrate, the printed circuit board is electrically connected with the EML laser chip through a first differential signal line and a second differential signal line on the printed circuit board, and the first differential signal line and the second differential signal line form differential routing; the coupling lens is arranged on the bottom plate and is close to the EML laser chip; and the filter capacitor is arranged on the printed circuit board and is electrically connected with the EML laser chip. According to the optical module packaging structure provided by the invention, the EML laser chip is driven by adopting a differential driving mode, so that the optical module packaging structure has higher anti-interference capability, and meanwhile, the signal transmission quality is improved.

The invention belongs to the technical field of SWISS rectifier control, and particularly relates to a three-phase single-stage SWISS rectifier control method for realizing phase compensation and reducing input current harmonics, and the method carries out voltage outer loop control through a single PI controller, and avoids a complex parameter adjustment process in a traditional double-PI control method. The single-cycle control based on the inductive current average value directly tracks a three-phase input current instruction, the influence of direct current side inductive current fluctuation on a control loop is reduced, and input current harmonics are reduced. The problem that the grid-side power factor is reduced due to the filter capacitor is solved through a phase compensation mechanism, and the power factor of the rectifier is improved. The method shows higher grid-side power factors and lower input current harmonics under different power levels, has the characteristics of simplicity in control and excellent performance, and is suitable for application scenes needing high-efficiency energy conversion and low harmonic pollution, such as new energy automobile charging piles and aviation power supplies.

The invention discloses a flyback conversion circuit, which comprises N flyback conversion sub-circuits and an input power supply circuit, and is characterized in that the input end of each flyback conversion sub-circuit is connected with the output end of the input power supply circuit; the flyback conversion sub-circuit comprises an input filter capacitor, a clamping capacitor, an output filter circuit, an active absorption circuit and M power conversion circuits; the first input end of the active absorption circuit is connected with the first end of the clamping capacitor, the second input end of the active absorption circuit is connected with the first end of the input filter capacitor or the second end of the input filter capacitor, and the first output end of the active absorption circuit is connected with the first input end of the output filter circuit. The second output end of the active absorption circuit is connected with the second input end of the output filter circuit. By adopting the design of multi-path staggered conduction control and unified energy absorption, the power conversion efficiency and power density of the circuit can be effectively improved, the voltage stress of the device is reduced, and the electromagnetic compatibility is improved.

The invention discloses a low-ripple closed-loop negative-voltage charge pump circuit in the technical field of analog integrated circuits, and the circuit comprises a charge pump closed-loop modulation circuit, the output end of the charge pump closed-loop modulation circuit is connected with the low-ripple negative-voltage charge pump circuit, and the low-ripple negative-voltage charge pump circuit is used for receiving positive power supply voltage input and outputting negative power supply voltage; the low-ripple negative-voltage charge pump circuit comprises a charge pump module, the first end of the charge pump module is connected with the first end of the positive power supply filter capacitor and the output end of the charge pump closed-loop modulation circuit, and the charge pump module outputs an output signal through the first end. By fixing the switching frequency of the low-ripple closed-loop negative-voltage charge pump circuit, the influence of switching noise on the system is reduced without repeatedly starting and stopping or changing the switching frequency of the charge pump, meanwhile, the size of a positive power supply is adjusted in a closed-loop mode through a negative feedback loop, and the voltage of the positive power supply of the charge pump is dynamically compensated. And the output voltage excursion of the traditional charge pump under large current is reduced.