31results about How to "Increase the ripple frequency" patented technology

The invention relates to a three-phase tri-level LLC resonant converter, which comprises an inverter, a three-phase transformer, a resonant circuit, a three-phase rectification circuit and a filter circuit, wherein the inverter is formed by connecting three tri-level bridge arms in parallel; the resonant circuit is formed by three groups of resonant capacitors and resonant inductances that are connected and three excitation circuits of the three-phase transformer; the three-phase rectification circuit is connected with the secondary edge of the three-phase transformer; and the filter circuit is connected with the output end of the three-phase rectification circuit. The three-phase tri-level LLC resonant converter is provided with a partial voltage capacitor used for equally dividing an input voltage source into two voltage sources with the voltage being half of the input voltage source; the three-phase tri-level LLC resonant converter is also provided with three groups of clamping circuits with zero-potential points being connected with the central point of the partial voltage capacitor, and the voltage stress endured by each switching pipe is clamped into half of the input voltage. The invention solves the problem that that the ripple current of an output filter circuit of a half-bridge LLC resonant converter, and the voltage stress of each switching pipe is half of the input voltage; in addition, the ripple frequency of the output current of the output filter circuit is improved by 6 times of the frequency of the switching pipe, and a filter element with smaller volume can be adopted, so that the volume of the output filter circuit is reduced.

The invention discloses an isolated three-level bidirectional DC-DC converter with a coupling inductor. The isolated three-level bidirectional DC-DC converter comprises a high-voltage side input capacitor, a low-voltage side input capacitor, a high-voltage side power supply, a low-voltage side power supply, a first power switching tube, a second power switching tube, a third switching tube, a fourth power switching tube, a first diode, a second diode, a third diode, a fourth diode, a first coupling filter inductor, a second coupling filter inductor, wherein the first coupling filter inductor and the second coupling filter inductor are coupled to each other. The isolated three-level bidirectional DC-DC converter has the advantages of small output current ripple and low loss of switching tubes, and is also relatively simple in structure.

An electric vehicle drive DC-DC converter and an electric vehicle are provided in which the electric vehicle drive DC-DC converter is constructed by connecting a plurality of DC-DC converter units in parallel, and in which a smoothing capacitor is allowed to be reduced in size thereof so that the DC-DC converter unit can be constructed in a small size, and electric power required by the electric vehicle can be coped with by only increasing the number of DC-DC converter units. Each of the DC-DC converter units includes: a coil having both ends thereof being connected to a DC power source and an electric vehicle drive source (motor); and a drive element which is connected in parallel to the electric vehicle drive source and driven in response to a signal supplied from a control circuit, the drive element having combined therewith a load current commutation diode. A single smoothing capacitor is connected in parallel to the electric vehicle drive source so that the respective drive elements of the plurality of DC-DC converter units are driven by the control circuit at different timings.

Provided in the invention is a composite power factor correction circuit comprising a power circuit and a control circuit. The control circuit is connected with the power circuit and is used for generating M*N-path phase-shift drive pulse signals and inputting the signals into the power circuit. The power circuit includes a rectifier bridge, M boost inductors, and an electrolytic capacitor; the output terminal of each boost inductor is respectively with N power devices; a positive terminal of the electrolytic capacitor is connected with a common terminal of negative output terminals of M backward fast recovery diodes to form a second positive output terminal; and a negative terminal of the electrolytic capacitor is connected with an emitter common terminal of M*N power devices to form a second negative output terminal. Besides, the control circuit includes a voltage outer-loop controller, M current inner-loop controllers, and a carrier generator; and each of the current inner-loop controllers is connected with N phase-shift comparison drivers. According to the invention, the power level can be effectively improved; the boost inductor design is simplified; the model selection and installation of the power devices can be realized conveniently; and the total cost is lowered.

The invention discloses an AC and DC dual-use energy storage and power regulation device and a control method thereof. The device comprises 3n cascaded H bridge units, 3n energy storage units, an AC output interface circuit, a DC output interface circuit and a central controller unit. The on-off state of an AC circuit breaker of the AC output interface circuit and a DC circuit breaker of the DC output interface circuit is controlled through the central controller unit, the energy storage device works in an energy storage inverter mode to be accessed to an AC power grid, or works in an energy storage DC converter mode to be accessed to a DC power grid; and the central controller unit adopts a corresponding control strategy to realize power dual-way controllable flow according to the work mode of the energy storage device. Through controlling different work modes of the energy storage device, the phenomenon that the energy storage system is accessed to an AC and DC hybrid microgrid is configured and managed flexibly, conversion of the power between AC and DC buses is realized more high efficiently, the power storage and transfer efficiency is improved, and the stability of the AC and DC hybrid microgrid is improved.

An apparatus of a hybrid power modulator using interleaving switching is provided. The apparatus includes a linear switching unit for generating an output signal by comparing an envelope input signal and a feedback signal, an interleaving signal generator for generating an interleaving switching signal arranged not to supply the signal to input stages of P-type Metal-Oxide-Semiconductor (MOS) Field Effect Transistors (FETs) and N-type MOS FETs of power cells at the same time by comparing the output signal and a reference signal, and a switching amplifying unit for determining a level of the switching signal using the interleaving switching signal. Hence, the hybrid power modulator using the interleaving switching method in the envelope signal of the wide bandwidth maintains high efficiency and high linearity. In addition, the buck converter can use the single inductor by preventing the simultaneous on/off of the power cells.

The invention provides an open-loop charge pump circuit capable of increasing an output voltage ripple frequency. The open-loop charge pump circuit comprises an overvoltage protection signal generation module, a work clock generation module, a boost control signal generation module, a boost module and an output voltage ripple detection and control module, wherein an input end of the overvoltage protection signal generation module is connected with an output end of the boost module, and an output end is connected with an input end of the boost control signal generation module; an output end of the work clock generation module is connected with an input end of the boost control signal generation module; an output end of the boost control signal generation module is connected with an input end of the boost module; and an input end of the output voltage ripple detection and control module is connected with an output end of the overvoltage protection signal generation module, and an output end is connected with an output end of the boost module. According to the invention, the output voltage ripple detection and control module is added on the basis of an original open-loop charge pump circuit, so that the problems of low tone quality and the like, which are caused by a too low voltage ripple frequency, are solved.

The invention discloses an open-loop charge pump. The open-loop charge pump is provided with a peak current limiting control circuit between a control circuit and a boosting circuit, drives the peak current limiting control circuit based on an overvoltage protection signal through the control circuit, and controls the boosting circuit to be in a charging phase or a discharging phase through the peak current limiting control circuit. When the output voltage is greater than an upper threshold voltage, the boosting circuit continues to be in the charging phase and stops powering an output load, and the output load is powered through discharging of an output capacitor. When the output voltage is less than a lower threshold voltage, the boosting circuit is in a normal operating mode. Thus, themusic noise problem caused by that the ripple frequency of the output voltage by the charge pump is within an audio range can be avoided, and the sound quality is improved.

The present invention specifically relates to a modularization subway energy feedback apparatus. To overcome a defect in the prior art that various power level requirements cannot be flexibly met, the present invention provides a series-parallel connection structure-based modularization subway energy feedback apparatus. The apparatus comprises: at least one DC750V inverse module group and a boosting transformer. Electric energy feeding into a direct current touch net enters a direct current side of the DC750V inverse module by using a voltage transformer, the DC750V inverse module converts a direct current into a low-voltage alternating current, and the low-voltage alternating current is changed to a middle-voltage alternating current by passing through the boosting transformer and then is fed into a medium-voltage power network. The DC750V inverse module group comprises at least one DC750V inverse module, and an alternating current output end of the DC750V inverse module is connected to the boosting transformer. The apparatus can flexibly cover different current level requirements with a voltage of DC750 or 1500V, and can perform redundancy running and improve reliability.

A soft-switching bidirectional DC/DC conversion circuit and converter, including k parallel-connected buck-boost circuits, the two bridge arm switches in each buck-boost circuit are switched in turn to enter the conduction state, and during the switching process there is In the dead zone, the driving waveforms of k buck-boost circuits are interleaved in time by 1/(k f _s ), f _s Represents the switching frequency of the buck-boost circuit, where the switching frequency f _s According to real-time changes in real-time input voltage, real-time output voltage and real-time output power, the f _s Make the circuit work in intermittent working mode, and the energy stored in the energy storage inductor can complete the charge and discharge of the parasitic capacitance in each bridge arm switch within the dead time, and maintain the diode during the freewheeling process in the dead time energy consumption. The invention has low conduction loss and switching loss, high efficiency, and can maintain high-efficiency operation in a wide range; material cost is reduced; current ripple is superimposed, and the ripple frequency is doubled while the peak and valley cancel each other, effectively reducing the high-voltage and low-voltage sides Filter volume; unitized design for easy expansion.

The invention discloses a three-phase three-level ANPC-DAB converter of a hybrid power device and a modulation method of the three-phase three-level ANPC-DAB converter, and belongs to the technical field of direct current-direct current converters. The driving modulation method suitable for the converter topology is provided by considering the particularity of the converter topology structure, current condition analysis in a time domain is effectively avoided, all switching loss is concentrated in a SiC MOSFET, the advantages of a SiC device are fully utilized, the switching loss of the converter is effectively reduced, and the conversion efficiency of the converter is improved. And the efficiency of the converter is improved. According to the method, a fundamental wave analysis method is adopted, an expression of the transmission power of the converter is obtained by means of a Fourier series expansion result, and a basis is provided for subsequent voltage and current modulation of the converter.

The invention discloses a circuit, which comprises a first bridge arm unit, a second bridge arm unit, a first capacitor and a second capacitor. Second ports for inductors of the first bridge arm unit and the second bridge arm unit are used for inputting cophase alternate current. Switch tubes of the first bridge arm unit and the second bridge arm unit are opened in a staggered manner to charge a first inductor and a second inductor, and the capacitance ripple waves are reduced. Under a working mode of a battery, the first bridge arm unit and the second bridge arm unit can still charge the inductors, and the circuit is not provided with idle devices, so as to improve the utilization ratio of the devices.

The high-frequency isolated AC-DC converter comprises a power factor correction circuit, an LLC resonant DC-DC converter and a topology reconstruction circuit, the output end of the power factor correction circuit is electrically connected with the input end of the DC-DC converter, the power factor correction circuit comprises three bridge arms which are connected in parallel, and the DC-DC converter comprises a fourth bridge arm and a fifth bridge arm which are connected in parallel; the topology reconstruction circuit comprises two bidirectional switch tubes, the first bidirectional switch tube is connected between the midpoint of the first bridge arm and the midpoint of the fourth bridge arm, and the second bidirectional switch tube is connected between the midpoint of the second bridge arm and the midpoint of the fifth bridge arm. And the topology reconstruction circuit is used for switching a two-stage circuit structure of the high-frequency isolation type AC-DC converter into a single-stage circuit structure. The high-frequency isolation type AC-DC converter provided by the invention can still operate normally under the condition that the switch tube breaks down, so that the fault-tolerant capability and the power supply reliability of the converter are improved.