1026results about "Ac-ac conversion" patented technology

The invention relates to the technical field of power conversion, and discloses an intelligent power converter system based on adaptive load regulation and a control method thereof. Comprising a power converter body, a plurality of sockets of different types are arranged on the power converter body, and a load sensing sensor, a micro-control unit, a step-down circuit and a bridge circuit are arranged in the power converter body; the load sensing sensor is electrically connected with the micro-control unit and is used for monitoring the power requirement of equipment connected with each socket in real time and transmitting a corresponding monitoring signal to the micro-control unit; the micro-control unit is electrically connected with the step-down circuit and the bridge circuit, and is used for controlling the step-down circuit and the bridge circuit to adjust output voltage and current according to a monitoring signal transmitted by the load sensing sensor; the micro-control unit controls the step-down circuit and the bridge circuit to automatically adjust the output voltage and current of the corresponding jacks according to the equipment power requirement monitored by the load sensing sensor, so as to realize the self-adaptive load adjustment of each jack.

A converter (2) supplies a load (3) with electrical energy from a supply network (4). Using a desired power (P1*) of the load (3) and a state (Z) of the supply network (4), a control device (9) of the converter (2) determines a power (P2*) to be output by the converter (2) to the load (3). The control device (9) determines, using the power (P2*) to be output, control signals (C, C1, C2) for the converter (2) and controls the converter (2) by means of the control signals (C, C1, C2) such that the converter (2) outputs the power (P2*) to be output to the load (3). The control device (9) determines the state (Z) of the supply network (4) using variables (UZK, a, f) on which the determination of the control signals (C, C1, C2) is based.

The invention discloses an ultrasonic transducer series resonant frequency tracking method and an ultrasonic driving power supply, and the tracking method comprises the steps: calculating a current phase difference between a voltage signal and a current signal, determining a phase difference error and an error change rate through the combination of a target phase difference, and determining the resonant state of an ultrasonic transducer according to the comparison of the phase difference error and an error threshold value; if the current driving frequency is in the resonance state, keeping the current driving frequency unchanged; and if in a non-resonant state, correcting the driving frequency through a fuzzy PID algorithm. In order to cope with the sudden change of the load, the tracking method introduces an AI model to identify the load and predict the optimal driving frequency, and then the predicted optimal driving frequency is used as the current driving frequency. According to the invention, the response speed and the adjustment precision in dynamic frequency tracking are improved, and adaptive resonance driving and frequency control of the ultrasonic transducer under variable load and variable working conditions can be realized.

The invention discloses a power and current prediction control method and system for a doubly-fed motor grid-side converter, and relates to the technical field of converter monitoring, and the method comprises the steps: predicting a current value, an active power value and a reactive power value of the doubly-fed motor grid-side converter in a next control period according to a power prediction model and a current prediction model; designing an improved value function by considering active power, reactive power and a current component of a dq axis under a dq coordinate system, and obtaining the action duration of a voltage vector in a next control period by minimizing the value function; and based on the action duration of the voltage vector in the next control period, controlling the power switch of the grid-side converter of the doubly-fed motor. According to the method, power and current parameter control of the doubly-fed motor grid-side converter under the three-phase balance working condition is considered, and efficient control of the doubly-fed motor grid-side converter under the three-phase power grid voltage balance condition is achieved.

A single-stage AC-to-DC resonant converter is used to convert a three-phase AC power source into a DC power source. The single-stage AC-to-DC resonant converter includes a primary-side circuit, a resonant circuit, and a secondary-side circuit. The primary-side circuit includes three primary-side switch circuits, and each primary-side switch circuit is coupled to one phase of the three-phase AC power source. The resonant circuit includes three transformers, and primary-side windings of the transformers are respectively coupled to the primary-side switch circuits, and secondary-side windings of the transformers are coupled to the secondary-side circuit.

A power converter, includes: a first terminal, a second terminal, a third terminal and a fourth terminal; stored-energy-source terminals, to which a stored energy source can be connected; four inverter bridge branches, which are formed from semiconductor switching devices, the inverter bridge branches each having a center tap, each center tap being assigned to one of the terminals, and the inverter bridge branches being interconnected and controllable such that electrical energy can be transferred bidirectionally between the stored-energy-source terminals and the first terminal, the second terminal, the third terminal and / or the fourth terminal; and a control unit, which is designed to control the semiconductor switching devices of the inverter bridge branches.

The invention provides a bidirectional flexible voltage regulation device for a power distribution network and a control method, and the device comprises a direct AC / AC type unidirectional voltage regulation topology which is connected with a power grid side and a load side of the power distribution network, and carries out the voltage regulation of the power distribution network; the mode change-over switch is connected with the direct AC / AC type one-way voltage regulation topology and is used for controlling the working mode switching of the direct AC / AC type one-way voltage regulation topology; the direct AC / AC type one-way voltage regulation topology is connected in series in a line of the low-voltage power distribution network through the mode change-over switch part, and bidirectional flexible voltage regulation when the voltage of the low-voltage power distribution network fluctuates or exceeds the limit is achieved. Through cooperation of the direct AC / AC type one-way voltage regulation topology and the mode change-over switch, a large-size transformer and a direct-current link are not needed, the operation of the mode change-over switch is controlled by detecting the voltage of the power grid, and real-time regulation of the output voltage is realized through closed-loop control; and bidirectional out-of-limit flexible voltage regulation of the power distribution network based on direct AC / AC type one-way voltage regulation topology and cooperating with the switch is realized.

The invention provides a power cooperative control method, device and system based on load removal and a medium. The method is applied to a micro-grid configuration flexible interconnection device for micro-grid fault protection. After the fault is positioned, a VSG low-voltage ride-through strategy is adopted to carry out current limiting, an importance quantification model is constructed for loads, and according to a real-time operation condition, a shearable load with the minimum influence on the system is screened to carry out priority removal; and dynamic power transmission adjustment of the flexible interconnection device is synchronously triggered, a micro-grid power flow path is reconstructed, and finally a fault is removed based on a current limiting and directional element protection method. According to the invention, system protection is realized by fusing intelligent load removal and flexible power adjustment, and the fault isolation speed and the stability of the microgrid system are effectively improved.

The invention discloses a current distortion suppression method and device for an N-phase AC-AC conversion system, and relates to the field of voltage conversion control, and the method comprises the steps: determining the ideal sine reference current of an xth phase, obtaining the actual input current of the xth phase in a current control period and the actual output current of the xth phase corresponding to an inductive load, and determining the current variation of the xth phase; and determining a difference value between the ideal sine reference current of the x-th phase and the actual input current as a real-time current distortion error signal of the x-th phase, further determining a compensation duty ratio of the x-th phase for suppressing current distortion by combining a preset duty ratio compensation strategy, and further determining a target duty ratio of the x-th phase as a target PWM signal. According to the scheme, the input current of each phase can be monitored, inductive load disturbance can be responded, the compensation duty ratio of the x-th phase used for restraining current distortion can be dynamically adjusted so as to determine the target duty ratio, the current distortion of the input current can be effectively restrained, and the input current can follow ideal sine reference current.

A electrical power system comprises: an electrical machine operable to output AC; a DC electrical network; a power electronics converter connected between the AC output of the electrical machine and the DC electrical network and including a plurality of transistors and associated diodes connected in parallel with the transistors; and a controller configured to control switching of the transistors of the converter so that, during normal operation of the electrical power system, the converter rectifies the AC output of the electrical machine to supply the DC electrical network with DC electrical power. The controller is further configured, responsive to a determination to the effect there is a fault in the DC electrical network, to control a voltage source, to inject a voltage to bias the diodes of the converter, and to control the switching of the transistors to control a level of current supplied to the faulted DC electrical network.

The invention discloses a high-efficiency converter for adjusting the voltage of a power grid, and belongs to the technical field of power electronics. The converter comprises a first voltage regulation circuit, a second voltage regulation circuit, a filter circuit, a detection circuit and a control circuit. By detecting the amplitude difference between the power grid voltage and the load voltage, the control circuit automatically switches the Buck working mode or the Boost working mode, and stable alternating current output in a wide input voltage range is achieved. The invention has the advantages of compact structure, high efficiency, fast response, small harmonic wave and the like, and is suitable for industrial and civil occasions with large-range fluctuation and frequent power grid voltage.

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 embodiment of the invention provides a current sharing control method and an AC-DC conversion system, the current sharing control method is applied to a current sharing controller, the current sharing controller is used for controlling the working state of an AC-DC converter, the AC-DC converter comprises at least two rectification units, and the at least two rectification units adopt a combination of a bridge topology structure and an LLC resonant tank; comprising the steps of determining a target adjustment phase according to absolute values of three-phase input voltage instantaneous values of at least two rectification units; according to the current sampling values of the at least two rectification units, a target duty ratio of a target adjustment phase in each rectification unit is determined, and the target duty ratio is used for indicating adjustment of the voltage gain of the LLC resonant tank; and adjusting the duty ratio of the control signal of the switching tube in each rectification unit according to the target duty ratio of the target adjustment phase in each rectification unit. According to the embodiment of the invention, the gain of the LLC is changed by adjusting the pulse width of the switching tube control signal in the rectification unit and adjusting the amplitude distribution of the input voltage of the resonant tank, so that the output current of the LLC is controlled, and the purpose of current sharing is achieved.

A power conversion system is provided, which system includes a first power converter including power electronic switches of a first type that are switchable to provide electric power conversion; and a second power converter connected in parallel to the first power converter. The second power converter includes power electronic switches of a second type that are switchable to provide electric power conversion. The second type is different from the first type. The second type of power electronic switches includes wide bandgap semiconductor switches. The system further includes a controller configured to operate the power conversion system in a first operating mode in which the second power converter is operated at a first switching frequency, and in a second operating mode in which the second power converter is operated at a second switching frequency of the power electronic switches and the first power converter is operated to provide power conversion.

The invention relates to the technical field of high-frequency and high-voltage power supplies, and discloses a dielectric barrier discharge load high-frequency and high-voltage power supply and control system, which comprises a power supply circuit, a Buck circuit and a series resonance inverter circuit, the control system comprises a frequency sweep starting control module, a zero-crossing phase-locked frequency tracking control module and a fuzzy PI control module. The system stability and the power supply dynamic performance can be improved.

The invention discloses a high-efficiency single-stage bidirectional power conversion topological structure capable of realizing full-range soft switching and a control method of the high-efficiency single-stage bidirectional power conversion topological structure. In a single-stage bidirectional power conversion topology formed by double half bridges and a switch matrix, a controlled current source connected in parallel with a primary side of a second transformer is designed; the current on a bridge arm connected with the primary side of the second transformer can be effectively changed, so that the soft switching range of a switching tube on the bridge arm in a wide power transmission range is widened, and full-range soft switching in a power frequency period can be realized in any load range; the controlled current source is designed to only work before and after the switching moment of the primary side switching tube of the second transformer, the current stress of the switching tube can be effectively reduced, and meanwhile, the loss of the additional controlled current source is very small. According to the invention, the working range of the soft switching is widened, the additional loss caused by the soft switching is greatly reduced, higher efficiency and higher power density can be realized, and the cost advantage is realized.

The present specification relates to a coil module and a home appliance including the same. A home appliance according to one embodiment of the present invention may comprise: a coil module comprising a plurality of first coil units stacked in a vertical direction and comprising a plurality of working coils, and a plurality of second coil units stacked in the vertical direction, a plurality of second coil units including a plurality of sensing coils and a wiring pattern electrically connecting the terminal unit with the working coil or the terminal unit with the sensing coils, and arranged in a different layer from the plurality of first coil units; and a control unit that performs container detection by using the sensing coil, and controls driving of the working coil in accordance with a result of the container detection.

A motor power source regulation circuit, a control method and an electronic device are provided. The motor power source regulation circuit includes a power factor correction circuit, an isolation circuit, a first power source conversion circuit, a second power source conversion circuit and a control circuit. The isolation circuit includes a first switch sub-circuit and an isolation transformer. The power factor correction circuit regulates an AC input signal to a first DC signal. The first switch sub-circuit converts the first DC signal to a first AC signal. The isolation transformer converts the first AC signal to two or more second AC signals. The first power source conversion circuit converts the second AC signal to a DC drive signal and outputs it to a DC motor. The second power source conversion circuit converts the second AC signal to an AC drive signal and outputs it to an AC motor.

The invention discloses a composite anti-interference voltage stabilization control method for a solid-state transformer rectifier stage, and the method comprises the steps: constructing a discrete full-order voltage model of the rectifier stage, and defining internal parameter change and external disturbance as variables to be observed, and enabling the variables to be equivalent to sum interference; designing a full-order stabilization control law to convert the model into a closed-loop system taking a tracking error as a state; constructing an intermediate observer, determining the gain of the intermediate observer by solving a linear matrix inequality so as to estimate sum interference on line, and solving an optimal solution of a quadratic cost function based on an optimal control theory so as to obtain a state feedback gain; and forming a composite anti-interference control law in combination with the interference estimation value and the state feedback gain, and inversely transforming the composite anti-interference control law into actual control input. According to the invention, through active observation and feed-forward compensation of interference, the voltage fluctuation of the DC bus is effectively suppressed, and the robustness and voltage stabilization precision of the system under complex working conditions are improved.

A power system 1 includes a power converter 6 and a control device 8. The power converter 6 includes a first converter circuit 71 including switching legs 61, 64 and a second converter circuit 72 including switching legs 62, 63. The control device 8 operates the power converter 6 under any one control mode among a charging mode for charging a high-voltage battery B by causing the converter circuits 71, 72 to operate as a PFC converter, a power feeding mode for feeding power to an external AC load EL by causing the second converter circuit 72 to operate as an inverter, and a power feeding during charging mode for feeding power to the external AC load EL while charging the high-voltage battery B by causing the first converter circuit 71 to operate as the PFC converter and causing the second converter circuit 72 to operate as the inverter.

Disclosed in the present invention is a high-voltage high-frequency SiC Mosfet novel power transformer, comprising a superordinate computer, a controller, an inverter circuit, and a signal detection circuit. The superordinate computer is connected to the controller; the inverter circuit uses a three-phase T-type inverter topology circuit to convert high-voltage power in a three-phase circuit into three-phase controllable AC power; the inverter circuit comprises a primary rectifier circuit, a primary DC-AC circuit, a three-phase winding transformer, a secondary rectifier circuit, and a secondary DC-AC circuit; a plurality of SiC Mosfets are used in the primary rectifier circuit, the primary DC-AC circuit, the secondary rectifier circuit, and the secondary DC-AC circuit; the signal detection circuit obtains detection data; and a DSP is provided in the controller, the DSP is provided with an algorithm module, the algorithm module performs an operation on the basis of the detection data to generate a specific instruction, and the controller adjusts the inverter circuit on the basis of operating parameters or the specific instruction. In the present invention, a plurality of SiC Mosfets are used, and the structure of the inverter circuit is optimized, thereby improving the working efficiency; and a detection and control feedback mechanism is additionally provided, so that effective regulation within the transformer can be realized, thereby improving the performance.

A dryer is provided. The dryer includes an alternating current (AC) power supply configured to supply an input voltage, a rectifier configured to rectify the supplied input voltage, a power amplifier configured to amplify the rectified input voltage to provide an output voltage, a plurality of electrodes to which the output voltage is applied, a matching circuit, connected between the power amplifier and the plurality of electrodes, configured to correct a waveform of the output voltage provided from the power amplifier, memory storing instructions, and at least one processor, wherein the instructions, when executed by the at least one processor individually or collectively, cause the dryer to obtain a magnitude of the output voltage provided from the power amplifier, and detect a power value corresponding to the rectified input voltage, based on the magnitude of the output voltage provided from the power amplifier being less than or equal to a defined reference voltage.

Provided are an uninterruptible power supply (UPS), a method and an apparatus for soft starting the UPS, and a controller. In the UPS, an inverter circuit is provided with three-phase output terminals, and two output terminals of a pre-charge circuit are electrically connected to output terminals of any two phases, respectively. The UPS charges a bus capacitor through an energy storage operation and a freewheeling operation, so that a voltage of the bus capacitor is greater than a peak value of a mains power. When the mains relay is powered on, a voltage of an end of the mains relay that is electrically connected to the mains power is lower than the voltage of the bus capacitor. Due to limitation of a conduction direction in a rectification circuit, no inrush current occurs, thereby reducing arcing of relay contacts and improving stability of the UPS during a power-on process.

The invention provides a current sharing control method and an AC-DC conversion system. The method comprises the steps that the method is applied to a current sharing controller, the current sharing controller is used for controlling the working state of an AC-DC converter, the AC-DC converter comprises at least two rectification units, and the at least two rectification units adopt the combination of a bridge topology structure and an LLC resonant tank; the method comprises the following steps: acquiring current sampling values of at least two rectification units; according to the current sampling values of the at least two rectification units, a target phase shift angle of each rectification unit is determined, and the target phase shift angle is used for indicating the duration when the input voltage of the LLC resonant tank is in a 0-level state; and according to the target phase shift angle of each rectification unit, controlling a control signal of a target switch tube in the bridge topology structure of each rectification unit to perform phase shift. According to the embodiment of the invention, the input voltage of the LLC resonant tank is 0 level by adjusting the phase shift angle of the switching tube in the rectification unit, so that the output current of each rectification unit is controlled, and the effect of current sharing of the outputs of the plurality of rectification units is achieved.

The invention provides a permanent magnet direct drive fan bus voltage oscillation suppression method after power grid fault recovery, and belongs to the technical field of permanent magnet direct drive fans. The technical problem of DC bus voltage oscillation after symmetric fault recovery is solved. According to the technical scheme, the method comprises the following steps that S1, the power difference value P between a computer side and a network side during a fault period and the maximum unbalanced power Pmax absorbed by the rotational inertia of a fan rotor are included, if P is smaller than or equal to Pmax, the step S2 is executed, and if P is larger than Pmax, the step S3 is executed; s2, controlling a direct-current bus voltage outer ring by a grid-side converter, and turning to S5; s3, a DC bus voltage outer ring is controlled by a fuzzy PI adaptive controller; and S4, carrying out fuzzy processing. According to the invention, adaptive adjustment of DC bus voltage outer loop PI parameters is realized, the dynamic response capability is enhanced, voltage oscillation is effectively suppressed, and the stability is improved.

The invention provides an uninterruptible power supply and a soft start method and device thereof, and a controller, in the uninterruptible power supply, an inverter circuit is provided with a three-phase output end, and two output ends of a pre-charging circuit are correspondingly and electrically connected with any two-phase output ends of the inverter circuit instead of being directly and electrically connected with a direct-current bus; when the uninterruptible power supply charges the bus capacitor through the pre-charging circuit, the bus capacitor can be charged through energy storage operation and follow current operation of the inverter circuit, so that the voltage of the bus capacitor is larger than the peak value of the mains supply, and when the mains supply relay is powered on, the voltage value of one end, electrically connected with the mains supply, of the mains supply relay is lower than the voltage of the bus capacitor. Due to the limitation of the conduction direction of the rectifying device in the rectifying circuit, impact current does not occur any more, the arc discharge phenomenon of a relay contact caused by the impact current is reduced, and the stability of the uninterruptible power supply in the power-on process is improved.

The invention comprises a method and apparatus for processing power, comprising the steps of: generating / using 3-phase power; feeding an AC drive with the 3-phase power, the AC drive generating a first output; and transforming the first output with a zigzag transformer, the zigzag transformer linked to at least one load output / load connector. The method and apparatus comprises an optional filter for filtering the 3-phase power prior to the step of transforming, the filter including a distributed gap core material.

A hybrid converter control method for offshore wind power, an apparatus, a device and a storage medium. The method comprises the following steps: S1, assigning a reference initial value for an effective value of an alternating current bus voltage of a hybrid converter, an operating angular frequency of the hybrid converter, and a reference value of an MMC direct current voltage, and acquiring an alternating current bus voltage of the hybrid converter, an effective value of the alternating current bus voltage of the hybrid converter, and an MMC direct current voltage; S2, calculating d-axis and q-axis components of the alternating current bus voltage of the hybrid converter in a dq rotating coordinate system; S3, calculating a reference value of the effective value of the alternating current bus voltage of the hybrid converter; S4, calculating a reference value of an MMC modulation voltage in the dq rotating coordinate system; S5, calculating an MMC modulation voltage in a three-phase stationary coordinate system; and S6, on the basis of the MMC modulation voltage in the three-phase stationary coordinate system, performing pulse width modulation to obtain trigger pulses for IGBTs of the MMC, thereby implementing steady-state control on the hybrid converter.

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 high altitude electromagnetic pulse (HEMP) or other similar geomagnetic disturbance (GMD) has the potential to severely impact the operation of large-scale electric power grids by introducing low-frequency common-mode (CM) currents which deteriorate the performance of key grid components, such as large power transformers. A solid-state transformer (SST) can replace susceptible equipment and improve grid resiliency by safely redirecting, absorbing, and / or converting these CM insults.