67 results about "Magnetizing inductance" patented technology

The invention relates to the technical field of electric variable data compensation, in particular to a metering error dynamic compensation method and system of an intelligent measuring switch. The method comprises the following steps: calculating to obtain phase delay compensation time of each sampling point based on original instantaneous current of each sampling point, equivalent excitation inductance of a current transformer, internal resistance of a secondary side winding, resistance value of a sampling resistor and a magnetic circuit saturation critical current value; performing high-order correction on the original instantaneous current to obtain a real current value of the sampling point; based on the original instantaneous voltage, the real current value and the phase delay compensation time of the sampling point in the metering period, the active power of the metering period is calculated so as to realize metering error dynamic compensation, and the accuracy of active power calculation of the intelligent measurement switch in the dynamic load switching process can be effectively improved.

The invention discloses a three-phase single-stage alternating-current and direct-current converter and a control method and device thereof, which are used for improving the conversion efficiency and the power density of the alternating-current and direct-current converter. The converter comprises a three-phase matrix switch circuit, a resonance circuit, an isolation circuit and a rectification circuit. The three-phase matrix switch circuit is connected with three-phase alternating current and comprises three switch branches which are independently arranged, each switch branch comprises an upper bridge arm and a lower bridge arm, the midpoint of the upper bridge arm and the midpoint of the lower bridge arm in each switch branch are connected with one phase of alternating current input, and each bridge arm comprises a bidirectional switch assembly or two switch assemblies which are reversely connected in series; the resonant circuit comprises a resonant capacitor, a resonant inductor and an excitation inductor which are connected in series, and is connected between the common endpoint of the upper bridge arms and the common endpoint of the lower bridge arms of the three switch branches; one side of the isolation circuit is connected with the resonance circuit, and the other side is connected with the rectification circuit; and the rectification circuit comprises at least two switch assemblies, the input side is connected with the isolation circuit, and the output side is connected with load equipment.

A power supply includes a converter circuit, a switching circuit and a control circuit. The converter circuit includes a transformer, a primary side switch and a secondary side switch. The switching circuit includes first and second capacitors, first and second sets of switches. In a first phase, the primary side switch is in the conduction state, causing a magnetizing inductor of the transformer to store energy. In a second phase, the primary side switch is in the off state, causing the magnetizing inductor to release the energy. In a first mode of the second phase, a first amount of the energy is transferred through the first set of switches to the first capacitor. In a second mode of the second phase, a second amount of energy is transferred to the second capacitor through the second set of switches.

The invention discloses a bidirectional DC-AC converter control method considering a soft switching condition and current optimization. According to the invention, the switching loss of the converter is reduced by optimizing the phase shift angle and the switching condition of the converter, and the energy transmission efficiency is optimized by minimizing the effective value of the current, so that the performance of the whole sodium battery energy storage system is improved. Specifically, based on the relation between the excitation inductance Lm and the current effective value Iprms, the phase shift angle of the converter is accurately controlled, the current transmission efficiency is optimized, and it is ensured that the zero-voltage switching condition of a primary side bridge arm and a secondary side bridge arm can be achieved in the working process, so that the loss of the converter is remarkably reduced, and the energy conversion efficiency is improved.

The invention provides a resonant converter parameter optimization method and system of an electric vertical take-off and landing aircraft, and relates to the technical field of aviation power electronics. The method comprises the following steps: constructing an improved equivalent circuit model containing transformer secondary side leakage inductance; deriving a voltage gain function expression of the improved equivalent circuit model and an optimization calculation formula of the excitation inductance required for realizing the soft switching; parameter optimization is carried out based on the voltage gain function expression and the excitation inductance optimization calculation formula; and building an LLC resonant converter experimental prototype according to the optimized parameters, and carrying out system verification and performance evaluation. According to the invention, the problem of performance reduction caused by neglecting secondary side leakage inductance under a high-frequency working condition in a traditional design is solved, the efficiency, the voltage stabilization precision and the power density of the converter are remarkably improved, and the high requirement of eVTOL on an airborne power supply is met.

A bidirectional DC / DC converter according to an embodiment of the present invention comprises: a transformer; a primary-side circuit connected to one side of the transformer and including a full-bridge circuit composed of first to fourth switches, a first resonant inductor, a magnetizing inductor, and a first resonant capacitor; and a secondary-side circuit connected to the other side of the transformer and including a full-bridge circuit composed of fifth to eighth switches, a second resonant inductor, a second resonant capacitor, and a third capacitor. In a mode in which power is supplied from the secondary-side circuit to the primary-side circuit among operation modes of the bidirectional DC / DC converter, the sixth switch is set to OFF, the eighth switch is set to ON, and the fifth switch and the seventh switch may be turned ON / OFF according to a first switching frequency.

This application provides an output control circuit, a flyback converter, a chip, and an electronic device. The output control circuit can obtain a first output voltage from a first output circuit and a second output voltage from a second output circuit, and control the first and second output circuits to conduct sequentially based on the first and second output voltages in each switching cycle. Therefore, the output control circuit can determine a first freewheeling circuit and a second freewheeling circuit in the first and second output circuits, so that the magnetizing inductance of the transformer in the flyback converter transfers energy to the first and second freewheeling circuits respectively during the secondary freewheeling phase. That is, the magnetizing inductance transfers energy using high-frequency chopping in each switching cycle, making the high-frequency chopping frequency of the first and second output circuits equal to the switching frequency. Since the switching frequency is usually higher than the range of human hearing, the problem of audio noise can be solved, and the performance of the flyback converter can be improved.

The application provides an efficiency optimization control method and device of a bidirectional LLC converter, and belongs to the technical field of power electronic conversion. The method comprises the following steps: determining the converter working mode of the bidirectional LLC converter based on the low-voltage battery side current, and determining the on-off control instruction of the switching unit based on the converter working mode; the bidirectional LLC converter comprises a resonant inductor, a resonant capacitor, a transformer, an external excitation inductor and a switching unit; the resonant cavity instantaneous current is subjected to zero-crossing detection and reference timing extraction to obtain a resonant current zero-crossing time reference signal; the zero-crossing synchronization driving signal of the switching unit is obtained based on the on-off control instruction of the switching unit and the resonant current zero-crossing time reference signal; the switching state of the external excitation inductor is controlled based on the zero-crossing synchronization driving signal of the switching unit, and the resonant cavity topology structure state of the bidirectional LLC converter is determined based on the switching state. The application can reduce the off loss and improve the conversion efficiency.

A power converter includes a transformer, a resonant circuit, a switch circuit, a resonant adjustment circuit, and a controller. The transformer includes a primary-side winding, a secondary-side winding, and a magnetizing inductance. The resonant circuit includes a first resonant capacitor, and the switch circuit includes a first switch and a second switch. The resonant adjustment circuit is coupled to the first resonant capacitor, and the controller is coupled to the resonant adjustment circuit. The controller controls the resonant adjustment circuit to adjust a resonant current flowing through the first resonant capacitor according to an output voltage of the power converter so as to adjust a current value that when the resonant current and a magnetizing current flowing through the magnetizing inductance intersect to be substantially equal to a predetermined value.

Disclosed in the present invention are a three-phase single-stage alternating current-direct current converter, and a control method and apparatus therefor, which are used for improving the conversion efficiency and power density of alternating current-direct current converters. Said converter comprises a three-phase matrix switch circuit, a resonant circuit, an isolation circuit and a rectification circuit. The three-phase matrix switch circuit is connected to three-phase alternating current, and comprises three independently arranged switch branches; each switch branch comprises an upper bridge arm and a lower bridge arm, a midpoint of the upper bridge arm and the lower bridge arm in each switch branch being connected to one-phase alternating current input, and each bridge arm comprising a bidirectional switch assembly or two switch assemblies connected in reverse series. The resonant circuit comprises a resonant capacitor, a resonant inductor and an excitation inductor connected in series, and is connected between a common endpoint of the upper bridge arms and a common endpoint of the lower bridge arms of the three switch branches. The isolation circuit has one side connected to the resonant circuit, and one side connected to the rectification circuit; the rectification circuit comprises at least two switch assemblies, an input side of which is connected to the isolation circuit, and an output side of which is connected to a load device.

The invention relates to the technical field of circuit system analysis, in particular to a method, a system and equipment for measuring parameters of a transformer. An excitation current source is applied to the primary side of a to-be-measured transformer, an open circuit of the secondary side is kept, the alternating voltage of the secondary side is measured, the real part and the imaginary part of the ratio of the alternating voltage of a secondary side winding to the alternating input current of a primary side winding are calculated, and the excitation resistance and the excitation inductance of a magnetic core are obtained according to the real part and the imaginary part. Stopping applying excitation, measuring port resistance and inductance from a primary side port, and calculating primary side leakage resistance and leakage inductance in combination with obtained excitation parameters; and opening the primary side, measuring the port resistance and inductance from the secondary side port, and calculating the secondary side leakage resistance and leakage inductance in combination with excitation parameters. The testing method is easy and convenient to operate, the calculation process is simplified, and the parameter measuring precision of the transformer is effectively improved.

The invention belongs to the technical field of power electronics, and discloses a wide-range zero-reactive LLC resonant converter based on a fractional order capacitor structure, which comprises a DC input voltage, an H-type inverter bridge consisting of Q1-Q4, a resonant inductor Lr, a resonant capacitor Cr and a resonant cavity structure consisting of an excitation inductor Lm, energy is transmitted to a secondary side through a transformation ratio N: 1 of a transformer, and the energy is transmitted to a secondary side through the resonant cavity structure. D1-D4 form a full-bridge rectifier which is connected with the secondary side of the transformer and is finally connected with a filter capacitor Cb and a load R, and the most important passive fractional order capacitor structure PFOC is connected in series into the resonant cavity structure. According to the invention, the inversion voltage in the passive fractional order circuit and the inversion voltage of the main circuit are controlled to be kept lagging by 90 degrees, so that the inversion voltage in the resonant cavity and the resonant cavity current realize a zero phase angle ZPA. When the ZPA is realized, the voltage gain of the LLC resonant converter is determined by the frequency, the frequency is inversely proportional to the voltage gain, and the voltage gain is less limited by the frequency.

The application provides a kind of multi-phase LLC-based direct current converter model prediction device and control method, specifically relates to direct current converter energy conversion technical field.The device includes two-stage converter cascade, input port has S, output port has N.The front stage is composed of S Buck circuits in parallel, each Buck circuit contains an inductor and two MOS tubes;The back stage is composed of N-phase LLC resonant converter, connected with the output port of the front stage Buck circuit.The front bridge of N-phase LLC resonant converter adopts half-bridge circuit, including two MOS tubes, resonant inductor, resonant capacitor and excitation inductor.The device adopts model prediction control method, the output voltage of next cycle is predicted to adjust relevant variables to maintain the purpose of output voltage.The application can access multiple voltage levels, model prediction control can be performed on direct current converter, voltage of specified voltage level can be output, voltage output can be effectively adjusted, and the demand of multi-scene application can be met.

The invention relates to the field of power electronic conversion, and provides a high-voltage transformer design method and system based on an LLC converter. The method comprises the following steps: determining size parameters of an iron core and size parameters of a winding according to resonance parameters of the LLC converter; determining parameters related to loss calculation according to the size parameters of the iron core and the size parameters of the winding so as to determine a loss formula; based on the resonance parameters of the LLC converter, solving the minimum value of the number of turns of the secondary side according to a loss formula, and obtaining the optimized number of turns of the secondary side; based on the resonance parameters of the LLC converter, solving a minimum value about the number of turns of the primary side according to a loss formula to obtain the optimized number of turns of the primary side; according to the excitation inductance parameter required by the LLC converter, the air gap with the set length is increased in combination with the iron core parameter; and performing flux density and temperature rise verification on the parameters calculated by the LLC converter, and obtaining a final design result after conditions are met. And the LLC converter can realize lower loss.

A lossless exciting current sampling circuit for an isolated converter includes first and second voltage sampling circuits and a subtraction circuit formed by an operational amplifier. The two sampling circuits sample voltages of the primary winding of an isolation transformer, with outputs fed into the subtracter. The subtracter output is the circuit's output. RC low-pass filters with large time constants are used as primary voltage sampling circuits, realizing integration of voltage differences between the exciting inductance terminals, enabling lossless current sampling without resistors or transformers. The current sampling result is utilized for volt-second balance control, realized along with a hold circuit and comparator which compares the sampling hold result with the current sampling result to generate a control signal.

The invention relates to an optical storage integrated grid-connected DC-DC converter and a control method thereof. The converter is characterized in that a high-voltage side adopts a half-bridge three-level structure and comprises at least two input support capacitors and two bridge arms, each bridge arm comprises at least two power switch tubes, and a connection midpoint of the two bridge arms is output to a resonant cavity; the CLLLC resonant cavity module comprises a resonant capacitor and a resonant inductor which are connected in series, an excitation inductor which is connected in parallel, and a transformer primary winding which is connected in series with the excitation inductor; a secondary winding of the transformer is connected in series with a resonant inductor and a resonant capacitor; the low-voltage side adopts a full-bridge rectification structure, comprises at least four power switch tubes and is connected with the secondary side of the resonant cavity; and the control module is used for generating a control signal to drive the switch tube to be switched on or switched off and implementing phase-shift change duty ratio control. According to the invention, the half-bridge three-level topology is adopted to reduce the voltage stress of the device, the CLLLC resonant topology and the phase-shift change duty ratio control are combined, the wide-range voltage gain adjustment and soft switching are realized, and the efficiency of the converter is improved.

The application provides an LLC converter and a wide-range voltage regulation method thereof. The LLC converter comprises an input voltage, an input inductor L in , a first half-bridge unit, a second half-bridge unit, a resonant cavity, a transformer, a rectifier circuit, an output capacitor and an output load. The first half-bridge unit is composed of a first switch S1, a second switch S2 and a bus capacitor C1, the second half-bridge unit is composed of a third switch S3, a fourth switch S4 and a bus capacitor C2, the resonant cavity is composed of a resonant capacitor C r , a resonant inductor L r and an excitation inductor L m , and the rectifier circuit is composed of a first rectifier diode D1, a second rectifier diode D2, a voltage doubler capacitor C3 and a voltage doubler capacitor C4. The application can realize soft switching of all power devices in a wide voltage gain range, the switching frequency is fixed at a series resonant frequency, which is beneficial to optimization and design of magnetic elements, and the capacitor voltage of the half-bridge unit in the LLC converter can be self-balanced.

The invention relates to the technical field of circuit system analysis, in particular to a method, a system and equipment for measuring parasitic parameters of a high-frequency transformer. Voltage is applied to the primary side of the transformer, the secondary side is open-circuited, the secondary side voltage is measured, and the real part and the imaginary part of the ratio of the secondary side voltage to the power supply voltage are calculated; stopping power supply, measuring resistance and inductance of a primary side port, and obtaining magnetization inductance, magnetic core equivalent resistance, primary side leakage inductance and leakage resistance in combination with the ratio parameters; and opening the primary side, measuring the resistance and the inductance of the secondary side port, and calculating the leakage resistance and the leakage inductance of the secondary side by combining the measured parameters. Complex electrical connection is avoided, operation is easy and convenient, measurement errors are small, parasitic parameters of the transformer under different frequencies can be measured, and therefore the dynamic change rule of the parasitic parameters of the high-frequency transformer along with the frequencies is obtained.

The utility model provides a kind of LLC resonant converter, including transformer primary side and transformer secondary side, the transformer primary side includes fractional order resonant network, the fractional order resonant network is constituted by one resonant inductance, one fractional order resonant capacitor, one excitation inductance. The utility model replaces fractional order resonant capacitor in traditional LLC resonant converter integer order resonant capacitor, by setting the order of fractional order resonant capacitor, it can effectively inhibit and maintain zero voltage switch (ZVS) state to surge current impact in LLC resonant converter starting stage, improve system efficiency.

The invention provides a direct current resonant converter with a wide voltage range, and relates to the field of direct current conversion, the direct current resonant converter comprises a switching circuit, a resonant cavity, a transformer and a secondary rectification circuit, the resonant cavity at least comprises a first resonant inductor, a second resonant inductor, a third resonant inductor, a resonant capacitor, and a leakage inductor and an excitation inductor of the transformer; the first resonant inductor is arranged between the switching circuit and the primary side of the transformer, the third resonant inductor is connected with the first resonant inductor in series, one end of the second resonant inductor is electrically connected with the positive end of input voltage, and the other end of the second resonant inductor is electrically connected with a connection node of the first resonant inductor and the third resonant inductor. The circuit has the advantage of widening the voltage gain.

The invention discloses a single-stage isolated AC-DC converter with a wide gain range and a modulation method thereof.The converter comprises a power frequency full-bridge circuit module, an FSBB converter module and an LLC resonant converter module which are connected in sequence, and each of the FSBB converter module and the LLC resonant converter module comprises two bridge arms which are connected in parallel; each bridge arm comprises two branches which are connected in parallel and formed by connecting two switching tubes in series, and the inductor is connected to a common node between the two bridge arms of the FSBB converter module in series; in the LLC resonant converter module, a primary winding of a transformer is connected in parallel with an excitation inductor and then connected in series with a common node between two bridge arms, and a resonant inductor is connected in series with a resonant capacitor and then connected in parallel with the excitation inductor to form a resonant cavity; the modulation method comprises the following steps: implementing a simplified frequency conversion control strategy on the FSBB converter module, performing fixed-frequency control in an intermittent conduction mode during light load, and performing frequency conversion control in a continuous conduction mode during heavy load; pulse frequency modulation control is carried out on the LLC resonant converter module; according to the invention, high-efficiency energy conversion in a wide input and output range is realized.

The invention relates to a method for evaluating electromagnetic parameters of a medium-high-voltage high-frequency transformer. The method comprises the following steps: inputting design parameters and electrical parameters of the high-frequency transformer; establishing a finite element model of the two two-dimensional sections, and performing finite element simulation according to the electrical parameters; primary and secondary side self-inductance parameters and primary and secondary side mutual inductance parameters are obtained based on finite element simulation, and excitation inductance and leakage inductance parameters are solved; sequentially calculating the average leakage magnetic field intensity of the position of each turn of winding based on the leakage magnetic field distribution of the transformer magnetic core window, and further solving the total winding loss of the high-frequency transformer; and obtaining the excitation voltage waveform of the high-frequency transformer based on the electrical parameters, establishing the relationship between the voltage and the magnetic flux density, and solving the iron core loss in combination with the iron core design parameters. According to the method, the electromagnetic parameter evaluation period of the medium-high-voltage high-frequency transformer is remarkably shortened, calculation resource consumption is reduced, powerful support is provided for rapid iterative optimization of a design scheme, and the method has good engineering practical value and popularization and application prospects.

The application discloses a kind of excitation inductance identification method, current control method and system of linear induction motor, belong to linear motor control technical field;In each control cycle, with back electromotive force as observation, the reference model based on sliding mode observer is constructed to calculate back electromotive force observation value, and adjustable model containing excitation inductance is used to calculate back electromotive force, and the adaptive rate of excitation inductance and back emf error is calculated to calculate the corresponding excitation inductance, to realize the identification of excitation inductance.The application constructs reference model irrelevant to the change of excitation inductance, and uses sliding mode instead of current differential term, eliminates the noise caused by current differential term in existing reference model, avoids the interference of current noise on back emf observation result, improves the accuracy of excitation inductance identification;On this basis, the inherent chattering problem of sliding mode observer is further eliminated by using cascaded low-pass filter, and the accuracy of excitation inductance identification is further improved.

This invention proposes a collaborative design method for the electrical-thermal-structural aspects of a high-frequency transformer in a CLLC resonant converter, considering voltage gain. Based on the high-frequency transformer's structural parameters, a mathematical model is established between the transformer's losses and structural parameters. The value of the magnetizing inductance is determined based on the CLLC resonant converter's voltage gain, further narrowing the constraint range. Using transformer losses as the heat source, and combined with the high-frequency transformer's structural parameters, a detailed thermal model of the high-frequency transformer is further established to calculate the temperature of key nodes. Finally, through the constraint relationship between losses, core area product, and temperature rise, the selectable range of transformer structural parameters is determined, and the core selection range is clarified.

A conversion system and a conversion method are provided. The conversion method is applicable to the conversion system, and the conversion system includes a conversion unit and a control unit. The conversion unit includes a first bridge arm, a second bridge arm, an input inductance element, a main capacitor element, a magnetizing inductance element, and a voltage transformation element. The conversion method includes: generating, by the control unit, a first duty cycle based on an output voltage of the conversion unit; controlling, based on the first duty cycle, the first switch and the second switch to be simultaneously turned on in an interval within a switching interval; and prolonging turn-on of one of the first switch and the second switch according to a polarity of an input voltage until a stop condition is met.

The present application discloses a control method for an asymmetric half-bridge circuit, a control chip, a power supply circuit, and a charger. The control method includes: acquiring first detection data of the asymmetric half-bridge circuit; when the first detection data satisfies a preset light-load condition, turning off the first switching transistor and acquiring a current output voltage and a current turn-off current of the first switching transistor; acquiring a current conduction time of the second switching transistor based on the current output voltage and the current turn-off current of the first switching transistor. The control method makes the second switching transistor's conduction time inversely proportional to the output voltage, stabilizing the magnetizing inductance demagnetization time and keeping the transformer's negative current within a preset range.

A method for operating a power converter comprises: providing an asymmetrical half-bridge flyback converter circuit, comprising a half-bridge with a high-side switch and a low-side switch, and a transformer with a primary winding and a secondary winding, wherein the primary winding is connected to the half-bridge and the secondary winding is connected to an output of the power converter; providing a clamping circuit coupled to the primary winding via an auxiliary winding of the transformer, wherein the clamping circuit comprises a third switch and a second diode connected in series; providing a controller configured to turn on and off the high-side switch, the low-side switch, and the third switch, and configured to operate the power converter in a critical line mode or in a discontinuous line mode.and during a third time interval of the discontinuous line mode, switching on the third switch, wherein the high-side and low-side switches are off during the third time interval, and wherein, by switching on the third switch, the clamping circuit prevents a free oscillation between a magnetizing inductance of the transformer and parasitic capacitances of the asymmetric half-bridge flyback converter circuit.

The invention discloses an LLC-DCX parameter optimization design method considering a backflow power factor, and relates to the technical field of power electronics, and the method comprises the following steps: S1, determining the transformation ratio and switching frequency of a transformer according to design requirements; s2, establishing an FHA model containing equivalent parasitic capacitance; s3, optimizing the excitation inductance and the dead time based on the total loss relation curve; s4, representing the backflow power by using the time lag so as to optimize the resonance parameter; and S5, correcting and judging parameters, ensuring that the sum of the total loss of the switching device and the backflow power is minimum, and completing global optimization. The method aims at solving the problems that the device loss rises and the system efficiency is reduced due to the fact that the backflow power is increased, through systematic optimization, the backflow power can be remarkably restrained, the device loss is reduced, and finally the optimal transmission efficiency of the converter is achieved.

A conversion device comprises: a transformer for generating an output voltage according to an input voltage; the current transformer is coupled to the first node of the transformer; one end of the resonant inductor is used for receiving the input voltage, and the other end of the resonant inductor is coupled to the current transformer at a second node; and the excitation inductor is coupled to the transformer at the third node, the excitation inductor is coupled to the resonant inductor at the second node and is adjacent to the resonant inductor, and the current transformer is arranged between the transformer and the resonant inductor along the first direction. According to the conversion device disclosed by the utility model, the occupied space on the printed wiring board is effectively reduced, and the magnetic flux generated by the resonant inductor and the excitation inductor to the transformer together is reduced. The disclosure also relates to a related manufacturing method.

This invention discloses a converter suitable for a wide range of output voltages and its control method. The converter includes a PWM half-bridge circuit. The control method includes the following steps: adjusting the switching frequency to put the PWM half-bridge circuit into discontinuous mode; when the PWM half-bridge circuit operates in discontinuous mode, the output inductor, the magnetizing inductance of the transformer, and the parasitic capacitance of the PWM half-bridge circuit oscillate; when the midpoint voltage of the primary-side switching bridge arm reaches its valley or peak, the corresponding power switch is triggered to turn on. This invention reduces switching losses by controlling the corresponding power switch in the PWM half-bridge circuit to turn on when the voltage across it oscillates to its valley.