51 results about "Active power decoupling" patented technology

The invention discloses a power factor corrector with an active power decoupling function and a control method thereof, Based on the current topology of step-up power factor correction converter, a buffering circuit is added to control the AC side current waveform and DC side output voltage directly, and the power fluctuation of double power frequency is transferred to the buffering capacitor automatically. The control objectives of correcting power factor and stabilizing output voltage are realized. The requirement of the converter for capacitor device is effectively reduced and the electrolytic capacitor is replaced by thin film capacitor, so the power density, service life and reliability of the converter are improved. At the same time, the proposed converter is based on step-up topology, and the DC-side current of diode full-bridge rectifier is continuous. Compared with the converter based on step-down topology and step-up-buck topology, the proposed converter has the advantages oflower AC-side high-frequency harmonic components and simplified filter design.

The invention provides a high-power-density single-phase cascaded H-bridge rectifier, a control method and a control method. The high-power-density single-phase cascaded H-bridge rectifier comprises an AC network side filter inductor and at least two cascaded power conversion units, wherein each power conversion unit comprises an H-bridge power unit, a decoupling unit and a DC side equivalent loadwhich are connected in parallel; wherein each decoupling unit is an independent buck type active power decoupling loop, and the decoupling units are used for buffering secondary ripple power so as toreduce the capacity of a DC bus capacitor.

The invention relates to the technical field of miniature single-phase photovoltaic grid-connected inverters, and particularly discloses a single-phase grid-connected inverter with an active power decoupling function, and a power decoupling control method of the single-phase grid-connected inverter. The inverter comprises a buck-boost converter, a single-phase two-bridge-arm inversion circuit, an alternating-current low-pass output filter circuit and an active power decoupling circuit, wherein the active power decoupling circuit is embedded into the single-phase two-bridge-arm inversion circuit to form a three-bridge-arm inversion circuit; a direct-current input source of the inverter is connected with an input end of the buck-boost converter; an input filter capacitor is connected in parallel between the direct-current input source of the inverter and the input end of the buck-boost converter; an output end of the buck-boost converter is connected with an input end of the three-bridge-arm inversion circuit; an output end of the three-bridge-arm inversion circuit is connected with an input end of the alternating-current low-pass output filter circuit; and power decoupling control is performed by a pulse width energy modulation method. The inverter can use a non-electrolytic capacitor as a decoupling capacitor and avoids an electrolytic capacitor, so that the fault interval time of the inverter is prolonged, and the reliability of a system is improved.

The invention discloses a photovoltaic grid-connected inverter with the active power decoupling function. The photovoltaic grid-connected inverter comprises a main flyback converter, a power decoupling converter, an inverter circuit and an output filter circuit. Decoupling between the output power of the photovoltaic grid-connected inverter and the output power of a photovoltaic module is achieved, the direct current voltage stabilization function of output of the photovoltaic module can be achieved by applying a non-electrolytic capacitor with small capacity to the direct current input side of the photovoltaic grid-connected inverter, and MPPT efficiency of the photovoltaic module is improved. An electrolytic capacitor is replaced by the non-electrolytic capacitor with high reliability, so that the problem that the overall service life of the photovoltaic grid-connected inverter is short due to use of the electrolytic capacitor is solved. Meanwhile, leakage inductance energy of a transformer can be absorbed and fed back, soft switching of a high-frequency operating switching tube of the main flyback converter is achieved, and conversion efficiency of the inverter is improved.

The invention provides a three-port single-phase single-stage inverter which comprises an input port, a modulation port, a controller, a commutator and an active power decoupling circuit port. The input port receives and transmits input power of a direct-current power supply. The modulation port generates a full-wave rectified sine wave current based on the input power. The controller generates switch control signals, inverting switch control signals, first pulse width modulation control signals and second pulse width modulation control signals. The commutator converts the sine wave current into an alternating current according to the switch control signals and the inverting switch control signals, and outputs the alternating current to a load-bearing device or a city power grid. The modulation port executes corresponding actions according to the first pulse width modulation control signals, and the active power decoupling circuit port executes corresponding actions according to the second pulse width modulation control signals.

The invention discloses an active power decoupling device without an additional switching element and a control method therefor. The active power decoupling device is achieved by increasing two additional energy storage capacitors in the topological structure of a conventional single phase current source converter. During each power frequency period, the energy storage capacitors work by turns to complete absorption and release of inherent secondary pulse power of the single phase current source converter. Compared with a conventional active decoupling device, the active power decoupling device provided by the invention requires no additional switching element, thereby helping reducing the system cost and improving the system efficiency. Direct current of the active power decoupling device is timely corrected by a decoupling circuit, and the mean value of voltage of a decoupling capacitor is maintained constant by a rectifier state circuit. The system control is not dependent on accurate system parameters, and the robustness is strong. Only a simple PI controller is required to achieve rapid and error-less tracking of a target, and the controller is easy to design.

The invention discloses a small-capacitance power converter and a power grid side electric energy quality control working method and a bus voltage suppression control method thereof. The power decoupling circuit is connected in series between a traditional diode rectifier and a direct current bus of a driving system, two energy transmission channels are constructed between a power grid and the direct current bus, and the flexibility of power grid pulsating power processing is remarkably improved. A controller of the active power decoupling circuit is constructed based on a virtual bus voltage concept, instantaneous voltage change of a decoupling capacitor is rapidly and accurately controlled according to working conditions of a driving system, bus voltage pulsation under various working conditions is remarkably reduced, and high-performance operation of the motor driving system under steady-state and dynamic working conditions is realized. Driving system power grid electric energy quality control based on the small-capacitance active power decoupling circuit and direct current bus voltage pulsation suppression are mutually decoupled, the complexity of a system controller is effectively reduced, high-performance operation of a motor is achieved, and meanwhile the power grid electric energy quality related harmonic standard is met.

The invention belongs to the field of power electronic control, and provides a cascaded H-bridge rectifier active power decoupling control method, a controller and a rectifier. The cascaded H-bridge rectifier active power decoupling control method comprises the following steps of acquiring the topology and operation parameters of a cascaded H-bridge rectifier, obtaining actual decoupling current given and expected decoupling capacitor voltage given, and constructing a decoupling bridge arm duty ratio model; and generating a PWM signal by using the decoupling bridge arm duty ratio model, and controlling the action of a decoupling bridge arm switching tube in real time.

The invention belongs to the technical field of power electronics, and specifically relates to an improved three-phase four-bridge arm topology for realizing active power decoupling used in a system containing a single / three-phase unbalanced load or source. The improved three-phase four-bridge arm topology comprises eight switch tubes S1, S2, S3, S4, S5, S6, S7, S8, four inductors La, Lb, Lc and Ln and five capacitors Ca, Cb, Cc, Cn, Cdc. When the single / three-phase unbalanced load or source exists, a fourth bridge arm is controlled, a passage is provided for a zero-sequence component by usinga center line, and then three-phase phase voltage balance is realized, and high-quality power supply is provided for the load; secondary impulse power on an alternating current side is provided by the capacitors on the alternating current side through active power decoupling control, a direct current side just needs to provide the average power component on the alternating current side, on the basis of without adding switch devices, a secondary impulse power decoupling purpose is realized, the tolerance of supporting capacitors on the direct current side can be reduced effectively, and the influence of secondary impulse power on direct current source or front system control performance is avoided.

The invention discloses a parallel active power filter system without an electrolytic capacitor, and a control method thereof, and belongs to the field of power electronic control. The system comprises a three-phase power grid, a harmonic load, a filter inductor, a two-level converter and a bidirectional Boost active power decoupling circuit. The control method of the system comprises the following steps: step 1, completing alternating-current and direct-current side power exchange by controlling the two-level converter so as to realize load harmonic compensation; and step 2, by controlling the bidirectional Boost active power decoupling circuit, transferring the low-frequency fluctuation power of the direct current side of the active power filter to the auxiliary capacitor tosuppress the low-frequency ripple of the voltage of the direct current side of the active power filter. A thin-film capacitor with a small capacitance value can be used for replacing a traditional electrolytic capacitor under the condition that the voltage fluctuation of the direct current side is small, and the cost is reduced, so the system reliability is improved. In addition, a low-pass filter in a direct-current side voltage control link of the active power filter is omitted, and the corresponding speed of the system is increased.

A single-phase device-multiplexing active power decoupling cascaded rectifier and control method thereof. The rectifier includes: n device-multiplexing active power decoupling H-bridge units that are cascaded, n≥2; each unit including: a bridge arm H1 and a bridge arm H2 connected in parallel, a decoupling capacitor branch formed by two capacitors connected in series, and a resistive load; a decoupling inductor being connected in series between a midpoint of the decoupling capacitor branch and a midpoint of bridge arm H2; and a bridge arm H1 of a first unit being sequentially connected in series to an inductor, resistor, and power supply, and then connected to a bridge arm H2 of a last unit. A power switch module of an H-bridge rectification unit is multiplexed, which not only realizes unit power factor rectification of the unit, but also provides a loop for secondary ripple power to achieve secondary ripple power decoupling control.

The invention relates to a photovoltaic circuit, a control method and device thereof, equipment and a storage medium, and relates to the photovoltaic field. The photovoltaic circuit comprises a photovoltaic cell, an active buffer circuit, a single-phase two-bridge-arm inverter circuit, a filter circuit and a power grid. The active buffer circuit comprises a thin-film capacitor, a power compensation circuit, a first decoupling switch tube and a second decoupling switch tube. An active buffer circuit is added in a photovoltaic circuit, through active power decoupling of a thin-film capacitor, a power compensation circuit, a first decoupling switch tube and a second decoupling switch tube, the stability of the direct current side voltage of a single-phase two-bridge-arm inverter circuit is maintained, and the influence of alternating current side power pulsation of the single-phase two-bridge-arm inverter circuit is avoided. The active buffer circuit can replace an electrolytic capacitor, the thin-film capacitor is small in capacitance value and long in service life, the stability of the inverter can be improved, and the problems that the direct-current side power of the single-phase inverter is maintained to be stable by using the electrolytic capacitor, the service life of the electrolytic capacitor is short, and the service life of the inverter is restricted are solved.

The invention discloses a parallel active power filter direct current side voltage low-frequency ripple suppression method, and belongs to the field of power electronic control. The method comprises the following steps of 1, connecting a direct current side split capacitor active power decoupling circuit in parallel on the direct current side of a traditional parallel active power filter; and 2, by controlling the active power decoupling circuit, transferring the low-frequency fluctuation power of the direct-current side of the active power filter to an auxiliary capacitor, and realizing low-frequency ripple suppression of the voltage of the direct-current side of the active power filter. Based on an active power decoupling technology, 6-frequency-multiplication, 12-frequency-multiplication, 18-frequency-multiplication and 24-frequency-multiplication fluctuation of the direct-current side voltage of the parallel active power filter is suppressed, a thin-film capacitor with a small capacitance value can be used for replacing a traditional electrolytic capacitor under the condition that the direct-current side voltage fluctuation is small, and the reliability of a system is improved. In addition, a low-pass filter in a direct-current side voltage control link of the active power filter is omitted, and the corresponding speed of the system is increased.

The invention discloses a parallel active power filter direct current side voltage low-frequency ripple suppression method, and belongs to the field of power electronic control. The method comprises the following steps: 1, connecting a bidirectional Buck-Boost active power decoupling circuit in parallel on the direct current side of a traditional parallel active power filter; 2, by controlling the bidirectional Buck-Boost active power decoupling circuit, transferring the low-frequency fluctuation power of the direct-current side of the active power filter to an auxiliary capacitor, thereby realizing low-frequency ripple suppression of the voltage of the direct-current side of the active power filter. Based on an active power decoupling technology, 6-frequency-multiplication, 12-frequency-multiplication, 18-frequency-multiplication and 24-frequency-multiplication fluctuation of the direct-current side voltage of the parallel active power filter is suppressed, a thin-film capacitor with a small capacitance value can be used for replacing a traditional electrolytic capacitor under the condition that the direct-current side voltage fluctuation is small, and the reliability of a system is improved. In addition, a low-pass filter in a direct-current side voltage control link of the active power filter is omitted, and the corresponding speed of the system is increased.

The invention discloses an active power decoupling type single-phase grid-connected converter based on a flyback circuit. The main circuit typology of the active power decoupling type single-phase grid-connected converter comprises a DC power supply, an input capacitor, a primary side switching tube, an isolation transformer, a secondary side switching tube, a filtering circuit, a power grid, andan active power decoupling circuit. According to the active power decoupling type single-phase grid-connected converter, the active power decoupling circuit composed of a decoupling switching tube, adecoupling diode and a decoupling capacitor is added to an input side of the converter, the low-frequency power pulsation at an input side of the DC power supply caused by AC output power is effectively decoupled, grid connection can be realized, and the long service life of the converter is guaranteed.

The invention relates to a power factor correction circuit, a control method of the power factor correction circuit, and a power factor correction device. A bridgeless converter circuit of the power factor correction circuit is connected with an active power decoupling circuit; the bridgeless converter circuit is connected with an external alternating current power supply; and the active power decoupling circuit is connected with an external load circuit. According to the power factor correction circuit, the control method of the power factor correction circuit and the power factor correctiondevice, the bridgeless converter circuit is adopted to realize the conversion from an external input alternating current to a direct current; the output direct-current side of the bridgeless convertercircuit is connected with the active power decoupling circuit; and low-frequency ripples in a direct-current power supply can be eliminated through the power decoupling control of the active power decoupling circuit. The power factor correction circuit not only has the advantages of low on-state loss and high efficiency in working but also can avoid the influence on the normal operation of the load circuit due to a large amount of the low-frequency ripples in the direct-current power supply provided for the external load circuit, and has high working reliability.

The invention belongs to the technical field of rail transit, and relates to the technical field of energy storage devices of motor train units, in particular to a secondary pulsation power decoupling method based on DC bus voltage detection. A passive LC resonant filter topology is replaced by a Buck-type bidirectional DC / DC converter, actual secondary pulsation power is obtained through detection of DC bus voltage and calculation, a target voltage instruction value of a decoupling capacitor is given accordingly, and active power decoupling is achieved through voltage and current PI double-closed-loop control. According to the method, active power decoupling is realized through the bidirectional DC / DC converter, the stability of the DC bus voltage is ensured, the overall power density of the traction converter is further improved, and lightweight operation of the motor train unit is facilitated; moreover, the method does not need to add a sensor, is easy for system transformation, and is a practical secondary pulsation power decoupling method.

A high-power density, single-phase cascaded H-bridge rectifier, a control method, and a control system. The high-power density, single-phase cascaded H-bridge rectifier includes: an alternating current (AC) grid-side filter inductor and at least two cascaded power conversion units, where each power conversion unit includes an H-bridge power unit, a decoupling unit, and a direct current (DC)-side equivalent load that are connected in parallel; and each decoupling unit is an independent buck-type active power decoupling circuit, and the decoupling unit is configured to buffer secondary ripple power, to reduce a capacity of a DC bus capacitor.

The invention relates to a new energy power generation technology, and aims to provide an active power decoupling method for introducing a three-phase voltage unbalance degree. Comprising the steps that voltage and current double-loop control is adopted for a three-phase energy storage converter of the T-type three-level topology; detecting a three-phase instantaneous voltage of the output side of the converter to obtain a three-phase voltage amplitude unbalance degree; pre-judging the unbalance degree of the voltage amplitude of the power grid, and continuing to execute if a preset condition is met; the three-phase voltage amplitude unbalance degree is introduced into three-phase power grid voltage dq conversion and calculation of a three-phase current feedback loop, and finally a PWM control signal is generated; and each switching tube in the converter executes actions based on the PWM control signal, so that the three-phase power is kept equal, and the frequency doubling power ripple is suppressed. According to the invention, frequency doubling ripple power oscillation under the working condition of unbalanced three-phase power grid voltage amplitude can be effectively eliminated, and the suppression target of DC side frequency doubling power ripples is realized; no additional hardware topology is added, an original control ring is reserved, and detection and control of positive and negative sequence components are omitted.

The invention discloses a multi-port converter based on topology integration and a control method and system, and relates to the technical field of power electronics. The multi-port converter comprises a first bidirectional full-bridge circuit connected with a power grid; a second bidirectional full-bridge circuit which is connected with an isolated three-port converter and shares two switching devices with the first bidirectional full-bridge circuit; an uncontrolled rectification full-bridge circuit which is connected with an output load and is connected with the second bidirectional full-bridge circuit through a first high-frequency transformer; a third bidirectional full-bridge circuit which is connected with the storage battery and is connected with the second bidirectional full-bridge circuit through a second high-frequency transformer; a first boost circuit which is connected with a photovoltaic cell and a direct current bus capacitor; and a second boost circuit which is connected with an active power decoupling capacitor and shares a switching device with the first boost circuit. Through the topology integration method, the number of switching devices can be reduced, so that the hardware cost of the multi-port converter can be reduced, the size and the weight can be reduced, and the integration performance can be improved.

A submodule (120) for a modular multilevel converter (102) includes a bridge cell (220) and an active power decoupling module (140). The bridge cell includes an energy storage capacitor (222) and a first bridge pair of power switches (224, 224') connected in parallel with the energy storage capacitor. The active power decoupling module includes first and second terminals (150, 152), a second bridge pair (169) of power switches (170, 170') connected between the first and second terminals and in parallel with the energy storage capacitor, and an inductor (166) connected in series with a power decoupling capacitor (168) to a junction between the power switches of the second bridge pair of power switches.

The invention relates to a quasi-single-stage AC / DC converter circuit capable of realizing active power decoupling. The AC / DC converter circuit comprises: an AC / DC converter circuit; the AC / DC converter comprises an AC / DC converter circuit, an input circuit, a totem-pole PFC circuit, a half-bridge DC / DC conversion circuit and an output load, and active power decoupling of the AC / DC converter circuit can be realized by controlling a third switching tube and a fourth switching tube of the half-bridge DC / DC conversion circuit. According to the invention, active power decoupling of the AC / DC converter can be realized without additional passive devices and complex auxiliary circuit control strategies, a high-capacity capacitor is not needed, and the reliability and stability of the system are greatly improved.

The invention discloses a non-isolated grid-connected inverter with active power decoupling function, comprising: a first inductor, a second power switch, a first power switch, a first diode, a second diode, First decoupling capacitor, second inductor, fourth power switch, third power switch, third diode, fourth diode, second decoupling capacitor, first DC power supply, second DC power supply, filter Capacitor, third inductance, detection circuit, control circuit; the detection circuit is used to detect the first inductance current, the second inductance current, the AC voltage of the power grid, and the grid current, and feed back to the control circuit, and the control circuit will The feedback signal of the detection circuit is converted into a driving signal and sent to the first to fourth power switches. The non-isolated grid-connected inverter with active power decoupling function provided by the present invention has a simple structure, realizes the decoupling of ripple power, and avoids the use of a large-capacity input filter, and is small in size and low in cost. efficient.

The present invention discloses a main circuit and method for suppressing low-frequency ripple in a two-stage single-phase inverter. The main circuit includes a bidirectional DC-DC converter and a single-phase inverter, with the input side connected in parallel and the output side connected in series. The input side of the bidirectional DC-DC converter is connected in parallel to an input power supply, and the output side is respectively connected in parallel to an output capacitor, and the two output capacitors are connected in series. The output side of the bidirectional DC-DC converter is connected in parallel to a single-phase inverter, and a filter inductor is connected in series at the output end of the single-phase inverter. The two series output capacitors of the bidirectional DC-DC converter have different capacitance values ​​and different DC operating points. The purpose of the present invention is to address the problem of suppressing low-frequency ripple in a two-stage single-phase inverter. The main circuit is designed to differentiate the capacitance value and DC operating point of the output series capacitors, so that the circuit itself has active power decoupling capability, significantly reducing the busbar capacitance requirement without introducing additional circuits, and achieving small capacitance, low ripple, and low cost for the system.

The invention discloses an active power decoupling control method and system based on hydro-thermal power coordination, and the method comprises the following steps: obtaining the frequency of a power grid and the power operation data of an external tie line, and calculating the area control error ACE of the power grid in a tie line frequency deviation control mode; respectively establishing active power control models of thermal power generating units and hydroelectric generating units; respectively dividing all hydroelectric generating units and all thermal power generating units in the power grid into a thermal power control group and a hydroelectric control group according to power generation types; decoupling ACE into two active power control signals by using a low-pass filtering algorithm, respectively distributing the two control signals to a hydroelectric control group and a thermal power control group, and then executing automatic generation control (AGC) normal control by respectively and correspondingly combining a hydroelectric generating set active power control model and a thermal power generating set active power control model; when the hydroelectric generating set sending-out transmission section set in the power grid is overloaded or overloaded, carrying out active power control of the hydroelectric generating set such that the control efficiency of the hydroelectric generating set is improved, and therefore the dynamic control quality of the hydroelectric generating set is improved.

The invention discloses an active power decoupling device and a control method without adding additional switching devices, which is realized by adding two additional energy storage capacitors in the topology of a conventional single-phase current-type converter. In each power frequency cycle, each energy storage capacitor works in turn to complete the absorption and release of the inherent secondary pulsating power in the single-phase current-source converter. Compared with conventional active decoupling devices, it does not need to add additional switching devices, which is beneficial to reduce system cost and improve system efficiency. The DC current in the active decoupling device is corrected in real time by the decoupling circuit, and the average value of the decoupling capacitor voltage is kept constant by the rectification stage circuit. The system control does not depend on precise system parameters, and has strong robustness; only a simple PI controller can realize fast and error-free tracking of the control target, and the controller design is easy.

The present disclosure relates to a quasi-single-stage AC / DC converter circuit capable of realizing active power decoupling. The AC / DC converter circuit includes: an input circuit, a totem-pole PFC circuit, and a half-bridge DC / DC converter A circuit and an output load, wherein, by controlling the third switching tube and the fourth switching tube of the half-bridge DC / DC conversion circuit, the active power decoupling of the AC / DC converter circuit can be realized. The present disclosure can realize the active power decoupling of the AC / DC converter without additional passive devices and complex auxiliary circuit control strategies, without the need of large-capacity capacitors, and greatly improves the reliability and stability of the system.

The invention relates to the technical field of miniature single-phase photovoltaic grid-connected inverters, and specifically discloses a single-phase grid-connected inverter with active power decoupling function and a power decoupling control method thereof. converter, a single-phase two-leg inverter circuit, an AC low-pass output filter circuit, and an active power decoupling circuit, the active power decoupling circuit is embedded in the single-phase two-leg inverter circuit to form a three-leg inverter circuit; the DC input source of the inverter is connected to the input terminal of the buck-boost converter, an input filter capacitor is connected in parallel therebetween, and the output terminal of the buck-boost converter is connected to the three-leg inverter circuit The input end of the three-bridge arm inverter circuit is connected to the input end of the AC low-pass output filter circuit; the power decoupling control is performed by using a pulse width energy modulation method. The present invention can use non-electrolytic capacitors as decoupling capacitors, avoiding the use of electrolytic capacitors, thereby prolonging the fault interval time of the inverter and improving the reliability of the system.

The invention discloses a cascade H-bridge STATCOM system without an electrolytic capacitor and a control method, and belongs to the field of power electronic control. The system comprises a three-phase power grid, a three-phase reactive load, a filter inductor and N three-phase cascade Buck multiplexing type H bridges, and N is greater than or equal to 2; the Buck multiplexing type H bridge comprises an H bridge formed by switching tubes S1-S4, a decoupling inductor Lr, and two thin-film capacitors Cd and Cr, the Cr is connected to the midpoint of a second bridge arm of the H bridge through the Lr to form a bidirectional Buck circuit, and the bidirectional Buck circuit and the second bridge arm of the H bridge realize switching tube multiplexing; the midpoint of the first bridge arm of the H bridge is connected with the midpoint of the second bridge arm of the previous H bridge, and the three phases are in star connection. On one hand, the bidirectional Buck circuit carries out active power decoupling, H-bridge direct current side fluctuation power is transferred to an auxiliary capacitor Cr through Lr, so that H-bridge direct current side voltage double frequency fluctuation is eliminated, a thin-film capacitor replaces an electrolytic capacitor, meanwhile, an H-bridge first bridge arm is assisted to complete alternating current and direct current side power conversion, and the power density and reliability of the device are improved.

The present disclosure introduces an integrated charging topology for operating a driveline solution for a sub-camera, wherein variants are proposed for both single-phase and multi-phase variants. The present disclosure introduces an active power decoupling variant using single input space vector decomposition and using power ripple phasors. This variant approach enables closed-loop control of harmonic output power ripples (e.g., second harmonics), compensates for unmeasured effects, such as interface inductance periodic energy storage, and allows for almost complete reduction in experimental settings. In operation, the control method may include controlling average power transfer between the grid and the battery and / or attenuating second harmonic power ripples.