14 results about "Cycloconverter" patented technology

Provided are a method for controlling a cycloconverter circuit, a cycloconverter circuit, and an isolated converter. The cycloconverter circuit is configured to perform alternating current to alternating current conversion and includes a plurality of switch elements connected in a plurality of current paths. The plurality of switch elements are divided into a plurality of groups of switch elements. Each group of switch elements includes at least one switch element disposed in each current path. The method includes: when the cycloconverter circuit is in a zero-crossing detection stage, controlling a first group of switch elements to be turned on complementarily and a second group of switch elements to switch between an on state and an off state. During a dead time between drive signals for the first group of switch elements, a first target switch element in the second group of switch elements is turned on.

The invention discloses a redecoupling method and system under asymmetry of bridge arm inductance of a bipolar AC-AC frequency converter. The bipolar AC-AC frequency converter is of an ABC three-phase structure, each phase comprises an upper bridge arm and a lower bridge arm, each of the upper bridge arm and the lower bridge arm comprises n full-bridge sub-modules connected in series and a bridge arm inductor, and the inductance parameters of the upper bridge arm and the lower bridge arm are different. Single-frequency output of a power frequency side and single-frequency output of a low-frequency side are achieved by applying the processing frequency difference mode reference voltage and the low-frequency common mode reference voltage to the upper bridge arm and the lower bridge arm, and mutual coupling of the power frequency side and the low-frequency side caused by asymmetry of bridge arm inductance is eliminated by applying the processing frequency common mode reference voltage and the low-frequency difference mode reference voltage to the upper bridge arm and the lower bridge arm. According to the invention, by introducing a re-decoupling control strategy based on a common mode and a differential mode, re-decoupling of the bipolar AC-AC frequency converter under the condition of asymmetric parameters is realized, unexpected harmonic components are eliminated, and the safety and reliability of the bipolar AC-AC frequency converter are effectively improved.

The present invention provides a wide-range soft-switching full-bridge inverter circuit and device based on controllable inductance. By changing the inductance values ​​of a first variable inductance unit and a second variable inductance unit during the process of inverting the DC power supply module by a phase-shifted full-bridge converter and a cycloconverter, the circuit achieves wide-range soft-switching operation of the phase-shifted full-bridge converter, thereby reducing switching losses of the inverter during operation and improving system conversion efficiency.

The invention discloses a variable-frequency power supply control method and device, the variable-frequency power supply comprises a high-frequency inversion module, a high-frequency transformation module, a cycloconverter and a control module, the high-frequency inversion module, the high-frequency transformation module and the cycloconverter are sequentially connected in series, and the control module is connected with the high-frequency inversion module and the cycloconverter. The control method comprises the following steps executed by the control module: collecting a target voltage input signal; an inversion control signal for controlling the high-frequency inversion module is output on the basis of a target voltage input signal in combination with the incidence relation between the high-frequency inversion module and the high-frequency transformation module; and in combination with the type of the cycloconverter, a transformation voltage signal output by the high-frequency transformation module is analyzed, a transformation control signal for controlling the cycloconverter is given, and control over the variable-frequency power supply is completed. By acquiring and analyzing a target voltage input signal, the high-frequency inverter module and the cycle converter are controlled, and high-power output of the variable-frequency power supply is realized.

The present invention discloses a bidirectional WPT AC-AC frequency conversion system based on a variable-topology bidirectional AC / AC system. The system comprises a variable-topology bidirectional AC / AC-1 unit, a wireless power transmission unit, and a variable-topology bidirectional AC / AC-2 unit, which are connected in sequence. The circuit has two energy transmission modes: forward energy transmission and reverse energy transmission. During forward energy transmission, the energy transmission path is: AB side → MN side of the variable-topology bidirectional AC / AC-1 unit → OP side of the wireless power transmission unit → variable-topology bidirectional AC / AC-2 unit → GH side; during reverse energy transmission, the energy transmission path is: GH side → OP side of the variable-topology bidirectional AC / AC-2 unit → MN side of the wireless power transmission unit → variable-topology bidirectional AC / AC-1 unit → AB side. The circuit of the present invention is capable of achieving efficient bidirectional wireless power transmission. Both the front and rear stages of the wireless power transmission circuit adopt a variable-topology bidirectional AC / AC solution to achieve a wireless power transmission frequency conversion output function, thereby improving system efficiency and reducing costs. The circuit is novel, reliable, and practical, and the control scheme is novel.

The utility model discloses a double-half-wave high-frequency chained micro inverter and a photovoltaic power generation system. The double-half-wave high-frequency chain type miniature inverter comprises a double-winding high-frequency transformer, a first half-wave type cycloconverter and a second half-wave type cycloconverter. The primary side of the double-winding high-frequency transformer is connected with the high-frequency inverter circuit, and the high-frequency inverter circuit is used for loading a generated signal waveform on the primary side of the double-winding high-frequency transformer; when the secondary side of the double-winding high-frequency transformer outputs a positive half wave, the first half-wave cycloconverter is used for transmitting the energy of the positive half wave to the output side; and when the secondary side of the double-winding high-frequency transformer outputs a negative half wave, the second half-wave cycloconverter is used for transmitting the energy of the negative half wave to the output side. According to the utility model, the efficiency of the inverter can be improved, and the output voltage is the voltage with completely equal amplitude.

A cycloconverter configured for use with a power converter is provided herein and comprises a bidirectional switch operable in a first mode of operation when an AC mains voltage is equal to or greater than a predetermined voltage and a second mode of operation when the AC mains voltage is less than the predetermined voltage, such that during zero voltage switching (ZVS) commutations a first Gate of a first pair of Gallium-Nitride (GaN) High Electron Mobility Transistors is on, a second Gate of the first pair of Gallium-Nitride (GaN) High Electron Mobility Transistors is off, and the first Gate and the second Gate of a second pair of Gallium-Nitride (GaN) High Electron Mobility Transistors are off.

The present application discloses a converter control method, a device, and a conversion circuit, belonging to the field of power technology. The converter control method includes: obtaining a first target voltage based on a sampling period within a dead time; the first target voltage is the voltage between the first end of a first switching tube and the first end of a third switching tube; within a target duration after the converter enters the dead state, when the first target voltage meets a target condition, controlling a target switching tube in the converter to turn on. The converter control method, device, and conversion circuit disclosed in the present application can more accurately determine the zero-voltage turn-on moment by obtaining the voltage between the first end of the first switching tube and the first end of the third switching tube and judging whether the voltage meets the target condition, aiming at the dead-time control of the AC-side cycloconverter. Through simple voltage detection, the zero-voltage turn-on moment can be determined more accurately, and then the dead-time duration can be dynamically optimized, and the overall conversion efficiency of the machine can be improved.

The present invention discloses a modulation system and method for a cycloconverter-type high-frequency link inverter, which includes a main circuit topology, a dual closed-loop controller, and a switch modulation strategy module. The method is as follows: starting from the voltage stress of the switch tube, the relationship between the voltage stress and the switch timing is analyzed, and the switch combination under different modulation strategies is obtained through the state of the transformer leakage inductance current under different modulation strategies, so as to realize the energy transmission between the primary and secondary sides of the converter; then, a dynamic mathematical model of the converter is established to obtain the transfer function of the system; a discrete controller is designed to obtain a reference modulation wave, and finally, by designing the logical relationship between the corresponding switch tubes, the safe soft commutation and converter function of the cycloconverter are realized. The present invention provides an effective modulation strategy for the high-frequency link inverter, and the transformer leakage inductance current naturally drops to zero, which can reduce the voltage stress generated by the discontinuous inductance current when the switch tube is commutated, and can realize the soft switching of the converter, which has high practicality.

The invention provides a cycle frequency converter fault-tolerant control method and system based on redundant bridge arms, and belongs to the technical field of frequency converter fault-tolerant control. The device comprises an AC-AC frequency conversion circuit formed by three N-phase input-single-phase output frequency conversion circuits, a j-phase unit comprises N normal working bridge arms, a redundant bridge arm and N bidirectional controllable normally-open switches, and each bidirectional controllable normally-open switch connects the midpoint o of the redundant bridge arm to the midpoints of the other N bridge arms; when a rear open-circuit fault occurs in the thyristor, the corresponding switch is closed, a trigger signal on the thyristor is transferred to the corresponding redundant thyristor, and the redundant thyristor is used for replacing the fault thyristor to conduct the circuit, so that smooth redundant switching of the frequency converter is realized, zero clearance and accuracy of redundant switching are realized, and the reliability of the frequency converter is improved.

An energy conversion device with an integrated active cell balancing circuit. The energy conversion device comprising a cell balancing circuit adapted to be connected to a plurality of cells of a battery, where the cell balancing circuit forms a DC bridge. A transformer, having a primary winding forming a portion of the cell balancing circuit, couples energy to a secondary winding. The secondary winding forms a portion of a resonant cycloconverter configured to convert the coupled energy to an AC output.

Method and apparatus for providing surge protection in a power conversion device. The apparatus comprises a surge protector, coupled to a resonant circuit of a cycloconverter, to bypass a tank current from the resonant circuit away from the cycloconverter when the power conversion device is being shut down.

The embodiment of the invention provides a control method of a cyclic wave conversion device, an inversion system and a storage medium, and belongs to the technical field of power electronics. The method comprises the following steps: acquiring a sampling alternating-current voltage corresponding to an alternating-current voltage output by a cyclic wave conversion device at the current moment and a zero-crossover interval; determining a first switch element and a second switch element of the cyclic wave conversion device under the condition that the sampled alternating current voltage is in the zero-crossover interval, each first switch element is in a high-frequency complementary switching state, each second switch element is controlled to perform high-frequency switching, and the high-frequency switching phase of the second switch element is the same as the high-frequency switching phase of the first switch element in one-to-one correspondence; the duty cycle of each second switching element is greater than the duty cycle of the first switching element. And the first switch element is a switch element for performing high-frequency complementation in a time interval except a zero-crossover interval in an alternating current half cycle. Through the method, the output reliability of the cyclic wave conversion device can be improved.

A converter circuit. In one aspect, the converter circuit includes an input terminal, a first output terminal and a second output terminal, and first, second, third and fourth capacitors coupled to a plurality of switches, where the plurality of switches are arranged to repetitively cycle the first, second, third and fourth capacitors between a first state and a second state to generate first and a second output voltages, where in the first state, the first and second capacitors are connected in parallel with each other and in series with a third capacitor to apply a first fraction of an input voltage at the first output terminal, and in the second state, the first and second capacitors are connected in series with each other and in parallel with the fourth capacitor to apply a second fraction of the input voltage at the second output terminal.