897 results about "Full bridge inverter" patented technology

The present invention focuses on the development of a high-performance solar photovoltaic (PV) energy conversion system. The power circuit of the invention is made of a two-stage circuit, connecting a step-up DC-DC converter and a full-bridge inverter in serial. The present invention uses an adaptive perturbation and observation method to increase tracking speed of maximum power position and at the same time reduces energy loss. In addition, the full-bridge inverter's output has to have the same phase with the utility power in order to achieve unit power factor and increase the system efficiency. The present invention uses voltage type current control full-bridge inverter to achieve the goal of merging into utility grid. The present invention provides an active Sun tracking system, by utilizing the character of changing in open circuit output voltage with Sun radiation strength to follow the Sun, and decreases the system cost and increases system effectiveness.

The present invention focuses on the development of a high-performance solar photovoltaic (PV) energy conversion system. The power circuit of the invention is made of a two-stage circuit, connecting a step-up DC-DC converter and a full-bridge inverter in serial. The present invention uses an adaptive perturbation and observation method to increase tracking speed of maximum power position and at the same time reduces energy loss. In addition, the full-bridge inverter's output has to have the same phase with the utility power in order to achieve unit power factor and increase the system efficiency. The present invention uses voltage type current control full-bridge inverter to achieve the goal of merging into utility grid. The present invention provides an active Sun tracking system, by utilizing the character of changing in open circuit output voltage with Sun radiation strength to follow the Sun, and decreases the system cost and increases system effectiveness.

A transformerless photovoltaic system that may benefit from inverter topologies more suitable for ripple current cancellation techniques is provided. In one exemplary embodiment, the system may combine basic modules of straightforward inverter topologies to meet requirements for higher power applications and may comprise a bipolar photovoltaic array, and a full-bridge inverter electrically coupled to the bipolar photovoltaic array. The full bridge inverter may comprise first and second inverter legs that may be arranged to energize two phases of a grid electrically coupled to the photovoltaic system. In one exemplary embodiment, switching signals applied to switching devices in each of the first and second inverter legs may be adjusted relative to one other to reduce ripple current therein, thereby reducing the size of components used by the system.

A multilevel cascade voltage source inverter having separate DC sources is described herein. This inverter is applicable to high voltage, high power applications such as flexible AC transmission systems (FACTS) including static VAR generation (SVG), power line conditioning, series compensation, phase shifting and voltage balancing and fuel cell and photovoltaic utility interface systems. The M-level inverter consists of at least one phase wherein each phase has a plurality of full bridge inverters equipped with an independent DC source. This inverter develops a near sinusoidal approximation voltage waveform with only one switching per cycle as the number of levels, M, is increased. The inverter may have either single-phase or multi-phase embodiments connected in either wye or delta configurations.

In an AC rotating machine, a stator is provided with N-phase stator windings and located relative to the rotor. The N is an integer equal to or greater than 3, and the N-phase stator windings are arranged to be electrically isolated from each other. An inverter circuit is provided with first to N-th full-bridge inverters. Each of the first to N-th full-bridge inverters includes a first pair of series-connected switching elements and a second pair of series-connected switching elements. The first pair of series-connected switching elements and the second pair of series-connected switching elements are connected in parallel to each other. Each of the first to N-th full-bridge inverters is configured to individually apply a single-phase AC voltage to a corresponding one of the N-phase stator windings to thereby create a torque that rotates the rotor.

A power system for a dielectric barrier discharge system, such as used for generating ozone, can include a full bridge inverter stage and parallel resonant tank outputting a signal for powering a dielectric barrier discharge cell stack. The inverter stage is controlled using a combination of pulse width modulation (PWM) and frequency modulation (FM) to enable soft switching through all load conditions—from full load to light load. A current control loop error amplifier compensator can provide a duty cycle adjustment signal to a phase shift PWM controller chip that generates the switching signals for the inverter stage. A feedback signal is also used to adjust a clock frequency time constant of the PWM controller chip to provide the FM. In one embodiment, the feedback signal is an output of an inverting amplifier connected at an output of the current control loop error amplifier compensator.

The invention relates to a pulse-width modulation (PWM) output method for solving the problem of nonuniform heating of a bridge arm switch of a single-phase full-bridge inverter circuit. The PWM output method is characterized in that two bridge arms use the modulation wave period T as an interval for alternately outputting PWM waves and square wave voltage. The problem of nonuniform heating caused by great work frequency differences of two bridge arm switches is solved, the temperature of an overheat switch is obviously reduced, insulated gate bipolar translator (IGBT) power switch device faults caused by overheat is effectively overcome, the reliability of a switch device is favorably improved, and the service life is prolonged.

The invention belongs to the field of electrical engineering, distributed power generation and power quality control, and aims to provide a multi-functional grid-connected inverter and a grid-connected inverter control method. The grid-connected inverter comprises a direct-current bus bar with a capacitor and three sets of single-phase full-bridge inverter circuits sharing the direct-current bus bar, the direct-current output ends of a distributed power supply or a grid-connected energy-storing generating set are connected to both ends of the capacitor of the direct-current bus bar, the output of each set of single-phase full-bridge inverter circuit is connected to a filter, and the output ends of each filter are connected with a distribution network of the 380V voltage class through a single-phase step-up isolation transformer. According to the invention, the grid-connected inverter equipment is effectively utilized to carry out effective control on the power quality of points of interconnection, so that the grid-connected inverter is multi-purpose and multi-functional, the cost performance of the grid-connected inverter is enhanced, the investment, operation and maintenance cost of a system can be reduced, and the reliability of the system can be enhanced. The principle of the provided control scheme is clear, and the control scheme is highly operable and reliable in operation.

The invention discloses a control method of a three-phase grid-connected inverter based on a modified proportional resonant regulator. The method comprises the following steps of: firstly, computing according to given active and reactive powers of the inverter and a voltage of a power grid to obtain required d-axis and q-axis currents under a synchronous coordinate system, and performing coordinate transformation by combining with phase information which is measured by a phase locking loop and a measured three-phase voltage signal of the power grid to obtain a current reference signal under a stationary alpha-beta coordinate system; secondly, performing coordinate transformation on an output current signal of the inverter to the alpha-beta coordinate system, controlling and tracking the current reference signal by the modified proportional resonant regulator with a harmonic compensator; and finally, returning to an abc coordinate system by coordinate transformation to generate a pulse-width modulation (PWM) pulse-control three-phase full-bridge inverter output, so as to make a distributed generation system grid-connected for power generation. By the method, a large number of complicated computation processes are eliminated, and a control structure is simplified. The control method of the three-phase grid-connected inverter based on the modified proportional resonant regulator is an accurate and high-efficiency novel inverter control method and has a bright development future.

The invention discloses an MMC (modular multiple converter) type multi-port power electronic transformer applied to an alternating current / direct current hybrid power distribution network. The multi-port power electronic transformer comprises an input level, a middle level and an output level, and are equipped with four kinds of universal interfaces: a high-voltage alternating current interface, a high-voltage direct current interface, a low-voltage alternating current interface and a low-voltage direct current interface; the input level refers to the MMC; the middle level refers to an isolating dual active full-bridge DC / DC converter; and the output level refers to a three-phase four-wire-system full-bridge inverter. Except the basic functions of voltage transformation, isolation, energy transfer and the like as a common transformer, the transformer provided by the invention can realize access of voltages of various forms with the multiple working modes, can perform functions of power flow control, electric quality adjustment and the like; and therefore, an intelligent power distribution network interface with higher applicability is configured.

The invention discloses a permanent magnet motor system with a shared bus structure and an open winding. The permanent magnet motor system comprises a permanent magnet synchronous motor, two current inverters, a direct-current power supply and a controller. The permanent magnet synchronous motor is of an open winding structure. The current inverters are voltage source type three-phase full-bridge inverters. The direct-current sides of the two current inverters are connected to the same direct-current power supply. Due to the fact that the direct-current sides of the two current inverters are connected directly, three current loops are formed in the structure. The invention further discloses a control method for suppressing a zero-sequence current of the permanent magnet motor system. According to the control method, a voltage compensator is designed for correcting the given voltage of the current inverters so that the zero-sequence current can be reduced substantially. According to the permanent magnet motor system, since the two current inverters share the same direct-current power supply, the structure is simple, cost is low, and operating performance and efficiency are high under the condition that the zero-sequence current is well suppressed.

The invention discloses a grid-connected current control method for a combined single-phase two-stage photovoltaic generation system. The single-phase photovoltaic generation system is of a two-stage structure and comprises a first-stage BOOST up circuit link and a second-stage single-phase full-bridge inverter circuit link. The single-phase full-bridge inverter circuit link adopts a double-closed-loop control strategy and comprises an outer loop which is a direct-current bus voltage loop and an inner loop which is a grid-connected current loop and further utilizes voltage forward feed control of a power grid. The BOOST up circuit link is used for realizing boosting voltage of a photovoltaic battery module to a direct-current bus voltage reference value while realizing maximum power point tracking. Besides, the single-phase full-bridge inverter circuit link is used for realizing stabilization of the direct-current bus voltage and synchronization of frequency and phase of system output current and voltage of the power grid. The grid-connected current control method for the combined single-phase two-stage photovoltaic generation system has the advantages of excellent stability, flexibility in dynamic response, low content of low-order harmonics, high interference resistance, good robustness, high reliability and the like.

An exemplary non-isolated DC-DC converter for a solar power plant, can be adapted to connect to a full-bridge inverter. The converter includes positive and negative input terminals, and positive and negative output terminals. A plurality of switches, diodes, inductors and capacitors are connected in a circuit configuration to the input and output terminals. A control means is connected to the circuit for controlling the switching of a first, second, and third switch between an open and closed state.

The invention discloses a pulse width modulation (PWM) control method for a single-phase grid-connected inverter, which is implemented according to the steps of: calculating to obtain single-polarity PWM wave; comparing network voltage detection with a zero crossing comparator to obtain a synchronous square wave signal, and then performing two divided-frequency on the synchronous square wave signal to obtain a synchronous square wave two divided-frequency signal; keeping only one of four power switch tubes of a single-phase full-bridge inverter in a high-frequency PWM action state, the power switch tube, which is on the diagonal of the power switch tube, of another bridge arm in a power frequency action state, and the other two power switch tubes in a shutoff state; making the four power switch tubes alternately act in a high-frequency PWM mode according to certain phase sequence; and adopting a principle that the power switch tube which conducts shuts off in advance to add dead zone time only during the zero crossing of network voltage at the same time. The method is applicable to single-phase grid-connected power generation systems, and has the characteristics of reducing the loss of switches, eliminating dead zone effect and optimizing heat dissipation.

Disclosed is a high-efficiency phase shift modulation method suitable for use in a traditional DC / AC single-phase full-bridge inverter. In this method, phase-shifted signal timing is used to modulate a duty cycle so that a power transistor is operated in a zero voltage switching state. As such, noises and switching loss of a switching device when turned on or off, may be reduced and thus efficiency of the inverter may be promoted. With this high-efficiency phase shift modulation method, at least the following advantages may be achieved: lower switching stresses, lower switching losses and thus increased conversion efficiency, lower electromagnetic interferences (EMIs) and no additional circuit required and thus easier realization of a controller for the inverter.

The invention discloses a brushless direct-current motor stator flux linkage identification method. The method comprises the following steps: the neutral point of a brushless direct-current motor is grounded to make the voltage of the neutral point clamped to zero; the brushless direct-current motor end voltage is determined through the on-off state of a power tube and a fly-wheel diode during the normal conduction process and the commutation process of a three-phase full-bridge inverter, wherein a three-phase phase voltage is obtained by performing subtraction between the three-phase end voltage and the neutral point voltage; detection is performed by adopting a current sensor to obtain a three-phase phase current, and calculation is performed according to the voltage model of the stator flux linkage to obtain a three-phase stator flux linkage; the three-phase stator flux linkage is filtered by a high-pass filter through CLARK transformation; and vector synthesis is performed on the three-phase stator flux linkage filtered by the high-pass filter to obtain a brushless direct-current motor stator flux linkage. According to the invention, advantages of less required motor parameters, simple structure, less calculation amount and low hardware cost can be realized.

The invention relates to a phase shift soft switch high frequency isolation photovoltaic grid-connected inverter which comprises a main circuit, a DSP control circuit, an ARM control circuit, and an auxiliary switch power supply circuit. The invention firstly provides a full digitalization control photovoltaic grid-connected generating system, wherein a high frequency full bridge phase shift circuit combined with a high and low frequency full bridge inverter circuit is main circuit structure, and high speed embedded digital signal processor DSPTMS320F2808 is a core. Maximal power point tracking of solar cell panel output power and isolation of photovoltaic direct current and electrical network alternating current are realized, software realizes phase-locked loop control, perfect grid-connected and islanding protection functions are provided, and the whole system can operate safely and reliably.

The invention provides a high voltage direct current power supply module controlled by DPS (data processing system). The high voltage direct current power supply module comprises a main power circuit and a DSP-based control circuit, wherein the main power circuit comprises an alternating current input unit, an EMC (Electro Magnetic Compatibility) protecting unit, a rectifying and filtering unit, a BUCK converter, a controllable phase-shift full-bridge inverter, a high frequency boost converter, a dual voltage rectifying unit and a filter, and the control circuit comprises a DSP control unit, a partial voltage feedback sampling unit, a DSP auxiliary power supply and a keyboard / display unit. According to the invention, the DSP is used as a control core to guarantee good controllability for the power supply, and the high voltage direct current power supply module is easy to upgrade and maintain. A DSP chip is used for realizing all-digital control on the main circuit of the power supply, and the output voltage is adjustable at a fixed point, so that the precision and stability of the output voltage are improved.

The invention relates to a high-efficiency voltage stabilization comprehensive control method of an induction power transmission system, belonging to the technical field of radio energy transmission.The system consists of two closed-loop circuits: an optimal efficiency tracking control loop and a robust constant pressure control loop. The optimal efficiency tracking control loop calculates the efficiency expression by establishing an AC impedance model for the system circuit, obtains the optimal equivalent load, adds an impedance matching network at a secondary side, and adjusts the duty cycle of a converter so that the equivalent resistance of the rectified output reaches the optimal load value to realize optimal efficiency tracking. The robust constant voltage control loop sends a difference between a load acquisition voltage and an input reference voltage into a robust controller by establishing a parameter perturbation model of the system to obtain a constant voltage of a high-frequency full-bridge inverter of a phase-shifted angle control primary side. The optimal efficiency tracking control and closed-loop robust control of an active impedance matching network can meet the multi-performance requirements of optimal efficiency and constant output voltage.

Systems and methods relating to zero voltage switching for inverters. A full bridge inverter is used in conjunction with a passive auxiliary circuit and an output filter. A control system controls the current by way of the auxiliary circuit and injects a high quality current to a power grid. The control system adjusts the duty ratio and switching frequency of the gate pulses applied to the power semiconductors in the full-bridge inverter. As well, the control system adjusts the phase shift between gate pulses for both the leading leg and lagging leg power semiconductors to control the current passing through the auxiliary circuit.

The invention relates to a coupling inductor dual buck full-bridge inverter, belonging to an electronic inverter. The inverter is composed of two buck circuits. One buck circuit comprises a first power switching tube (S1), a second power switching tube (S2), a first flywheel diode (D1), a second flywheel diode (D2), a first coupling inductor primary winding (L1A), a first coupling inductor secondary winding (L2A), a filtering capacitor (Cf) and a load (RL); and the other buck circuit comprises a third power switching tube (S3), a fourth power switching tube (S4), a third flywheel diode (D3), a fourth flywheel diode (D4), a second coupling inductor primary winding (L1B), a second coupling inductor secondary winding (L2B), a filtering capacitor (Cf) and a load (RL). The inverter circuit adopts the coupling inductor to effectively reduce volume and loss of magnetic elements and improve inversion efficiency; and solves the direct connection of the power tube of the bridge arm of the bridge inverter, so as to improve the reliability.

The invention provides a wireless electric energy transmission system compensation topological structure, relates to the wireless electric energy transmission system compensation topological structure, and aims at solving the problems that the existing wireless electric energy transmission system compensation topological structure is high in the number of compensation devices, high in system cost and low in power density. The S / CLC compensation topology comprises a primary series compensation capacitor, a loosely coupled transformer, a secondary parallel compensation capacitor, a secondary series compensation inductor and a phase shifting capacitor. The primary series compensation capacitor is connected with a full-bridge inverter. The primary series compensation capacitor is connected with the primary self-inductor of the loosely coupled transformer. The primary self-inductor of the loosely coupled transformer is connected with the full-bridge inverter. The secondary self-inductor of the loosely coupled transformer is connected with the secondary parallel compensation capacitor and the secondary series compensation inductor. The secondary self-inductor of the loosely coupled transformer is connected with the secondary parallel compensation capacitor, the phase shifting capacitor and a full-wave rectifier. The secondary series compensation inductor is connected with the phase shifting capacitor and the full-wave rectifier. The wireless electric energy transmission system compensation topological structure is used for wireless electric energy transmission.

The AC power generated by AC utility has been successfully transferred from AC-to-DC by means of an AC-to-DC converting circuit. This disclosure provides an AC-to-DC converting circuit applicable to a power-charging module, and the AC-to-DC converting circuit comprises two parts such as a first stage being a low-frequency AC to high-frequency AC converter comprising an input full-bridge rectifier, a full-bridge inverter and an immittance conversion circuit and a second stage being an AC-to-DC converter comprising a single-phase transformer and a full-bridge rectifier, where the inverter in the first stage is switched at high frequencies so as to reduce the size of the transformer in the second stage. Additionally, the immittance conversion circuit is further characterized in voltage to current conversion so as to simplify the control mechanism of the power-charging module, reduce the number of current measuring elements and the cost thereof.

The invention discloses a grid-connected inverter control method based on a state observer. The grid-connected inverter control method comprises the steps that (1) a bridge arm current iL1 and network voltage eg are detected, and a phase angle theta is obtained through phase locking of a phase-locked loop; (2) an observation state quantity is obtained through the state observer based on an internal model; (3) a state quantity feedback signal Xfd is obtained through a state feedback matrix K; (4) grid currents of an observational network are processed, and then grid current error signals ed and eq are obtained; (5) closed-loop processing is carried out on the grid current error signals ed and eq through a PI controller, and then through coordinate inverse transformation, wave generation voltage ui1 is obtained; (6) the wave generation voltage ui1 and the state quantity feedback signal Xfd are subtracted from each other to generate a SVPWM control signal ui of an inverter bridge switching tube, output of a three-phase full bridge inverter is controlled, and therefore a distributed power generation system is controlled to be combined to the grid. Practices show that the control method obtains good dynamic and steady-state performance for a grid-connected current.

The present invention discloses an electric converter circuit topological structure and a control method thereof. The circuit topology comprises a full-bridge inverter, a primary side resonance dynamic compensation network, a primary side coil, a secondary coil, a secondary resonance dynamic compensation network, a full-bridge synchronous rectifier and a load. The primary side resonance dynamic compensation network employs a structure of connection in series of a compensation inductor and an adjustable resonance capacitor, the secondary resonance dynamic compensation network employs a structure of connection in series of a coil and the adjustable resonance capacitor, in the conditions that system parameters are changed caused by factors such as different coil coupling coefficients, different loads, the temperatures and device production manufacturing errors, the PWM duty ratio of a capacitive switching switch is regulated to generate continuously changed and adjustable equivalent resonant capacitance to perform dynamic compensation for the resonance network to achieve the soft switch of the full-bridge inverter and minimize the reactive power in the energy transmission of the system so as to maximum the electric energy transmission efficiency of the system and effectively enhance the regulation ability of the system output features in a condition of the constant working frequency of the system.

The invention discloses a grid-connected inverter for low-frequency current ripple output restraining of a fuel cell and a control device. The grid-connected inverter comprises the fuel cell FC, a boosting converter, a full bridge inverter and an LCL filter. The control device comprises a voltage sensor, a current sensor and a DSP digital controller. The boosting converter comprises an inverse-current-preventing diode, an input filtering capacitor Cin, a filtering inductor LB, an electric MOSFET and an output capacitor CDC. The full bridge inverter comprises four electric MOSFETs. The LCL filter comprises a capacitor C1 and two inductors L1 and L2. The DSP digital controller comprises a proportioner, a phase-locked loop, a subtracter, a PI adjuster, a multiplying unit, a summator, a signal generator, a comparer and a phase inverter. By establishing the boosting converter, energy decoupling on an input side and an output side is achieved, the fact that currents on the input side do not contain low-frequency ripples is guaranteed, the manufacturing cost of the grid-connected inverter is lowered, power conversion efficiency is improved, and an electric energy converting device suitable for fuel battery power generation is achieved.

The invention proposes a solid-state transformer with an alternating current-direct current fault continuous operation capability and a control method. A hybrid modular multi-level converter bridge arm consists of a half-bridge sub-module and a full-bridge sub-module; the half-bridge sub-module and the full-bridge sub-module are interconnected with input ends of isolated dual active bridge converters through a sub-module direct current capacitor; output ends of multiple isolated dual active bridge converters are connected in parallel to form a low-voltage direct current bus; and the low-voltage direct current bus is connected to a three-phase full-bridge inverter. The solid-state transformer provided by the invention can provide a medium-voltage direct current port, a medium-voltage alternating current port, a low-voltage direct current port and a low-voltage alternating current port, so that multi-voltage-grade and multi-form alternating current-direct current hybrid power distribution network interconnection can be realized; the solid-state transformer has the alternating current-direct current fault continuous operation capability, quick switching of device operation modes whena short circuit or open circuit fault occurs on a network connected to any port can be realized, and continuous operation between non-faulty ports can be ensured, thereby improving the power supply reliability of the alternating current-direct current hybrid distribution network.

The invention discloses a comprehensive control method for a high-power efficient energy consuming high-frequency switching power supply. The high-power efficient energy consuming high-frequency switching power supply comprises a three-phase current inverter and a high-frequency DC / DC (Direct Current to Direct Current) converter, wherein the high-frequency DC / DC converter consists of a single-phase full-bridge inverter, a high-frequency coupling transformer and a low-voltage rectifier which are connected in series in sequence; the input end of the three-phase current inverter is connected with a group of three-phase capacitors connected in a Y form, and is connected with a power grid through a three-phase inductor L; and the three-phase current inverter is connected with the single-phase full-bridge inverter of the high-frequency DC / DC converter. According to the method, quick response of a system is realized, change of a load is tracked quickly, efficient power consumption of the system is realized, and the voltage and current distortion factors of the system are decreased.

The invention discloses a composite control method for a grid-connected inverter based on repetitive control and a disturbance observer. The method comprises the following steps: (1) acquiring network voltage, grid-connected current and capacitance current; (2) acquiring network voltage phase angle through PLL phase locking of the network voltage, converting the grid-connected current and the capacitance current to alpha belta coordinates through transformation of coordinates; (3) adjusting the network voltage phase angle, as well as the grid-connected current and the direct current reference signal thereof both under the alpha belta coordinates through repetitive control; (4) subtracting the output value of the disturbance observer and the capacitance current under the alpha belta coordinates from the output value of the repetitive control; (5) converting the output value after final subtraction to abc coordinates through transformation of coordinates, and generating PWM (Pulse Width Modulation) impulses to control the output of a three-phase full-bridge inverter, so that the grid-connected power generation of the distributed power generation system is achieved. According to the composite control method, the dynamic property of the overall grid-connected control system is good, the steady accuracy is high and the robustness is strong; the composite control method is an accurate and efficient inverter control method, and has a bright development future.

The invention relates to an aerial three-level electric excitation motor starting control method and an aerial three-level electric excitation motor starting control device. The method comprises the following steps of: determining the controller output voltage vector in the mode of directly controlling the module value of the voltage vector and an included angle between the voltage vector and a main generator rotor, transmitting a switching signal of a three-phase full-bridge inverter in a mode of modulating a support vector machine (SVM) through a space vector, controlling the inverter to drive the main generator, and realizing the starting function of the three-level electric excitation synchronous motor. The aerial three-level electric excitation motor starting control method has the advantages that 1) the control links are fewer, a speed ring PI regulator and a current ring PI regulator are independent, and the parameters are conveniently adjusted; 2) real-time state information of the system is not required, the acquired original information of the main generator can be processed by using a complicated filtering algorithm, the information has certain robustness on transient interference, and the control performance of the system can be effectively improved; and 3) control objectives are fewer, and the comprehensive control error caused by electromagnetic interference of an exciter on the main generator can be effectively reduced.