506 results about "Phase shift control" patented technology

Disclosed is a family of new DC/DC converters and a new control method. The converter comprises two bridge inverters, two full-wave rectification circuits and a current-doubler filter. Each inverter is able to generate a symmetrical and isolated AC output voltage. Phase-shift control is employed to control the phase difference between the two bridge inverters. By shifting the phase, the converter changes the two inverters' output voltage overlapping area to regulate its output voltage. The bridge inverters always operate at 50% duty cycle, like an open loop Bus Converter, to achieve wide-range zero voltage switching and eliminate circulating current for normal operation. For low output voltage regulation and soft start, Pulse Width Modulation (PWM) control is used. The converters and the control method improve power conversion efficiency, maximize magnetic component utilization, reduce semiconductor stress and decrease EMI emission.

A switching power supply device includes a full-bridge circuit, a transformer, a rectifier circuit, a filter circuit, a first series connection of a snubber capacitor and a first diode, and a second diode. The full-bridge circuit includes switching elements which are controlled to be driven under phase-shift control. The first series connection is connected in parallel with the smoothing reactor, where one terminal is connected to a terminal on positive side of the rectifier circuit, and the other terminal is connected to an anode of the first diode. A cathode of the first diode is connected to one terminal of the smoothing capacitor which is applied with positive voltage. The second diode is provided between a terminal on negative side of the rectifier circuit and a connecting point of the snubber capacitor and the first diode. A cathode of the second diode is connected to the connecting point.

The present invention is a circuit and method for reducing switching and reverse recovery losses in the output rectifiers while creating zero voltage switching conditions for the primary switchers. There are described two output configurations, one employing a soft commutation inductor element a bridge rectifier and a output filter capacitor, the second using a soft commutation inductor element a rectification-filtering bridge composed by two capacitors and two capacitors. Both secondary circuits can be driven by three primary circuits. A first circuit is a full bridge with phase shift control, and a second circuit is a half bridge topology with an additional bydirectional switch which achieves two goals, on to get soft switching commutation across all the primary switches, the second to create the right waveforms in the secondary suitable with the claims in this invention. The third topology is a phase shifted two transistors forward. The circuits claimed in this invention can provide soft commutation across the primary switching elements and secondary rectifier means, clamping the voltage across the rectifiers to the output voltage eliminating the need for snubbers circuits both in primary and the secondary section.

A tri-phase modular multi-level converter and a fault-tolerate detecting method for an IGBT (insulated gate bipolar translator) open circuit fault in sub-modules thereof belong to the field of electronics and aim to solve the problem that the whole machine cannot work caused by the open circuit fault of the existing MMC. The invention adopts a method of connecting two hemi-bridge power units in parallel in each sub-module of the converter, and the IGBT with the open circuit can be positioned by measuring the output voltage UA of the sub-modules and simultaneously applying a certain phase shift control on the IGBTs in the two hemi-bridge power units in at most half alternating current period, and the modular multi-level converter can be continuously operated when any IGBT in any sub-module is subjected to open circuit fault, thus solving the problem of low reliability and frequent halt for repairing of the traditional modular multi-level converter. In addition, the conducting loss of the IGBT can be reduced due to the parallel connecting work mode of the power units and the converting efficiency of the electric energy of the converter is improved.

The invention provides alternating-current phasor analysis method and small signal model modeling method suitable for dual-active bridge (dual active H bridges, dual three-level half bridges or a three-level half bridge on one side and an active H bridge on the other side and the like) direct-current converters in all phase-shifting controls. The alternating-current phasor analysis method and small signal model modeling method comprise the specific steps as follows: (1) an alternating current side of each active bridge is equivalent to two square-wave voltage sources through equivalence, and square-wave voltage is decomposed into superposition of sinusoidal voltage through Fourier series decomposition to obtain phasor expressions, as shown in the specification, of (2n+1)th component voltage and inductive current; (2) phasor diagrams of control characteristics and control ranges under different phase-shifting controls are obtained according to the phasor expressions in the step 1; (3) complex power, as shown in the specification, of the (2n+1)th component is obtained according to the phasor expressions in the step 1, and active and reactive power characteristics of the dual-active bridge direct-current converters under different phase-shifting controls are analyzed; and (4) time domain Fourier series and expressions of the voltage and the current are obtained according to the phasor expressions in the step 1, so as to obtain a unified signal model suitable for all phase-shifting control methods.

The improved quadrature phase shift keying modulator has a structure such that the average light output power of phase-shift keying modulation light output from the combining unit is changed according to the phase difference between the first and the second optical signal after being combined by means of applying driving signals different in eye crossing percentage by the first modulator and the second modulator, respectively, and has a power monitor monitoring the average light output power of quadrature phase-shift keying modulated light and a phase shift controlling unit which performs feedback control of the phase shift amount in the phase shifting unit based on the average light output power monitored by the power monitor.

The invention relates to a multi-sub microgrid-contained mixed microgrid system and a control method thereof. The mixed microgrid system comprises a photovoltaic subsystem, an energy storage subsystem, a direct-current bus, a DC/AC converter and an alternating-current subsystem. The control method comprises the following steps: controlling running modes of the photovoltaic subsystem and the energy storage subsystem according a power grid instruction; controlling the running mode of the photovoltaic subsystem by using a perturbation observation method-based photovoltaic generation maximum power tracking method; and controlling the running mode of the energy storage subsystem by using a method of combination of dual-closed loop control and phase-shift control. Compared with the prior art, the provided system and the method have the advantages of electrical isolation realization, high security, and stable bus voltage and the like.

A bidirectional DC/DC converter includes first and second control circuits, and first and second bridge circuits respectively connected to first and second direct current voltage supplies. In one embodiment variant, when power is supplied from the first direct current voltage supply to the second direct current voltage supply, the first control circuit carries out PFM control of the first bridge circuit at a frequency equal to or lower than the resonance frequency of an LC resonant circuit in accordance with a control amount based on the voltage and current of the second direct current voltage supply. When power is supplied in the other direction, the second control circuit carries out fixed frequency control of the second bridge circuit, using phase shift control or the like, in accordance with a control amount based on the voltage and current of the first direct current voltage supply.

The invention relates to a multi-purpose two-way power electric test power supply system and a control method thereof. The system comprises a PWM reversible rectifier and an active clamp two-way DC/DC converter. The method comprises the steps as follows: a single-polarity SPWM control is adopted at a first stage; a first stage circuit has a power factor correcting function when power flows forwardly, and a PF value is very high; when the power reversely flows, the total harmonic distortion is low; a phase shift control or a PWM control is adopted at a second stage; when the power flows forwardly, the adjustment range of output DC voltage is wide; and after an active clamp circuit is adopted, soft switching of a switch tube of a second stage circuit is achieved, so that the multi-purpose two-way power electric test power supply system has relatively high efficiency under different load conditions. An all-digital control is adopted by a power supply; compared with a traditional electric test power supply, the multi-purpose two-way power electric test power supply system has the characteristics of being small in size, light in weight, diverse in function and the like, and is suitable for the occasions of electric operation, an inspection experiment, storage battery charging and discharging and the like.

The invention relates to a control method of a dual-active-bridge converter, and aims to provide a triple-phase-shift control method of the dual-active-bridge converter. According to the triple-phase-shift control method, an output voltage controller used for adjusting an output voltage is arranged in the dual-active-bridge DC converter of a bi-directional topological structure, an input signal ofthe output voltage controller is a difference value between a given value of a secondary side DC voltage and an actual measured value, and an output signal of the same is a control signal alpha whichis used for adjusting a duty ratio D1 of a primary side bridge arm neutral-point voltage, a duty ratio D2 of a secondary side bridge arm neutral-point voltage and a phase difference D3 of the voltages. The triple-phase-shift control method solves the problems of dual-active-bridge current stress optimal solution and control complexity, obtains the corresponding D1, D2 and D3 when the inductive current stress is minimum under each power point, solves relationships among the D1, D2, and D3, proposes the simple control method, and can realize the effect that the converter operates according to atrajectory with the minimum current stress by using just one PI controller.

The invention discloses a soft-switching welding inverter power supply, a phase-shifting control method and a soft-switching method which belong to the electronic circuit field. The soft-switching welding inverter power supply comprises a full-bridge converter and a control module; the phase-shifting control method is applied to the power supply, and comprises the steps as follows: the control module receives current signals of the full-bridge converter, and adjusts dead-zone time of phase-shifting signals based upon the current signals; the soft-switching method is applied to the power supply, and comprises the steps as follows: an auxiliary resonant network is connected with a bridge leg of the power supply in parallel so as to provide subsidiary energy to the zero voltage turning-on of a switching element; before the switching element of a lagging leg on the full-bridge converter is turned off, main power loop current flowing through the switching element is weakened, and the reversion of the main power loop current is restrained; and an absorption capacitor is connected with the switching element in parallel, and the borne rate of voltage rise is slows down when the switching element is turned off. The soft-switching welding inverter power supply, the phase-shifting control method and the soft-switching method realize the zero-voltage zero-current soft-switching in full range of loads including idle load and short circuit.

A phase shift control method for a boost converter and circuit implementation comprises a master phase and at least one slave phase. A master-phase inductor current flowing through the master phase has a master-phase charge time interval and a master-phase discharge time interval; a slave-phase inductor current flowing through the slave phase has a slave-phase charge time interval and a slave-phase discharge time interval. The method comprises: calculating an ideal switching timing whereat the slave-phase inductor current descends to a zero-current judgment value; obtaining a physical switching timing whereat the slave-phase charge time interval starts; calculating a conduction timing error between the physical switching timing and the ideal switching timing; determining the time length of the slave-phase charge time interval in the same cycle according to the conduction timing error and the master-phase charge time interval.

The invention prevents the voltage change ratio of switching devices of a power converter from exceeding a specified maximum rating, thus avoiding damage in switching devices and an increase in conduction loss. In a power converter having a plurality of switching devices, switching means for switching a control scheme for the switching devices to a phase shift control scheme or a pulse width modulation scheme is provided, whereby the control scheme for the switching devices is switched from the phase shift control scheme to the pulse width modulation scheme in a non-load or light-load state.

The invention provides an LCL type induction electric power transmission control device. The LCL type induction electric power transmission control device comprises a primary grade part and a secondary grade part, and is characterized in that the primary grade part is provided with two closed loops, namely a frequency converting control loop and a phase-shifting control loop; the frequency converting control loop adopts a frequency tracking method to control the frequency of a high-frequency inverter circuit door control signal; and the phase-shifting control loop adopts a phase-shifting control policy of an intelligent subdivision control algorithm to control a phase-shifting angle of the high-frequency inverter circuit door control signal. The LCL type induction electric power transmission control device is only used for controlling at the primary grade, and a conventional information feedback channel does not need to be used between the primary grade and the secondary grade.

The invention relates to an online projection objective wave aberration detection device and method. The detection device comprises a light source, a rotary scatterer, a first focusing lens, an optical fiber array, a second focusing lens, a scattering optical element, an object plane optical grating, an image plane optical grating, a two-dimensional photoelectric sensor, a phase-shift control module and a computer, wherein the rotary scatterer is composed of a support, an electric motor and a circular diffusion scattering optical element, and is combined with the multimode optical fiber array for converting a coherent light or partially coherent light source into incoherent light; ten interference fringe patterns with phase shifting amounts of 0, pi/6, pi/3, pi/2, 2pi/3, 5pi/6, pi, 5pi/3, 3pi/2 and 11pi/6 respectively are acquired to calculate a phase position and the influence of multilevel diffraction light interference of the optical grating on the phase position extraction precision is eliminated. The device and the method can improve the modulation effect of the object plane optical grating on the optical field spatial coherence so as to achieve a high-precision alignment effect, reduce the system error of phase position extraction in wave aberration detection and improve the wave aberration detection precision of an optical system.

The invention provides a correction policy of current zero-crossing distortion applicable to all one-way three-phase rectifiers (including three-phase VIENNA rectifiers, three-phase bridgeless rectifiers and all star-connection cascaded three-phase rectifier topologies) based on single-period control. The policy specifically includes following steps: firstly, determining related parameters of a system, then calculating a current distortion initial point, a distortion time and a boundary condition, and finally calculating a parameter introduced compensation amount based on the above parameters.According to the policy, based on the characteristic of single-period direct current control, crossed injection is performed on the feedback of current phase-shift control signals, and superpositionis performed with an original phase-shift feedback amount so that zero-crossing distortion generated by current phase shift of the energy one-way flow three-phase rectifier is corrected without increasing the complexity of the system. According to the policy, the realization is simple, the reliability is high, an effective correction method is provided for the current zero-crossing distortion problem occurring in a single-period control process, and the application range of single-period control is extended.

The invention discloses a transient state phase-shifting control method for a double-drive full-bridge DC/DC converter and belongs to the field of power and electronic technologies. The method includes the steps that at a steady state period, an AC output side of a first full-bridge of the double-drive full-bridge DC/DC converter is adjusted to be a square wave vh1 with the duty ratio being 50%, and a phase position is fixed; an AC output side of a second full-bridge of the double-drive full-bridge DC/DC converter is also adjusted to be a square wave vh2 with the duty ratio being 50%, equal phase-shifting angles are arranged between the rising edges of the square wave vh1 and the square wave vh2 and between the falling edges of the square wave vh1 and the square wave vh2 respectively; at a transient state time period, the phase-shifting angles are changed from phase-shifting angles D1 of a first switching period T1 to phase-shifting angles D2 of a second switching period T2, in the second switching period T2, the phase-shifting angle between the rising edge (or the falling edge) of the square wave vh2 and the falling edge (or the rising edge) of the square wave vh1 is adjusted to be a phase-shifting angle D20, and the phase-shifting angle between the falling edge (or the rising edge) of the square wave vh2 and the rising edge (or the falling edge) of the square wave vh1 is the phase-shifting angle D20. The transient state phase-shifting control method for the full-bridge DC/DC converter can reduce current shock and accelerate dynamic response.

The invention discloses a closed-loop control method for battery full-range charging. The method is based on an open-loop circuit of a wireless power transmission system. The open-loop circuit of the wireless power transmission system comprises a direct-current power supply, an inverter, a primary-secondary resonant network, and a rectifier, wherein the direct-current power supply, the inverter, the primary-secondary resonant network, the rectifier and a battery are connected in sequence. The method comprises the following steps: which stage the battery is in is judged, wherein the charging stages of the battery include a constant-current charging stage, a constant-power charging stage, and a constant-voltage charging stage; when the battery is in the constant-current charging stage, the inverter is controlled in a fixed-frequency phase shift control method; when the battery is in the constant-power charging stage, the inverter is controlled in the fixed-frequency phase shift control method; and when the battery is in the constant-voltage charging stage, the inverter is controlled in a frequency-hopping phase shift control method. Through the method, full-range efficient battery charging is realized. The system is of high safety and stability.

The invention provides a main and standby satellite clock time frequency signal seamless switching device and a main and standby satellite clock time frequency signal seamless switching method. The device comprises an atomic clock group comprising three atomic clocks, wherein each atomic clock is correspondingly and electrically connected to a path of AD (analog-to-digital) sampler, an input signal selection unit is connected with all AD samplers and a main control unit, first and second frequency and phase extraction units, a phase shifting control unit and first and second phase shifting units realize the frequency and phase extraction and phase shifting, main and standby frequency difference and phase difference measurement units measure the main and standby clock frequency difference and phase difference for completing the main and standby clock synchronization, a main clock and a constant temperature crystal oscillation phase difference measurement unit are connected with a main and standby clock signal selection unit and form a feedback loop through a filtering unit, a DA (digital-to-analog) output unit and a constant-temperature crystal oscillation unit, and the main clock and constant temperature crystal oscillation synchronization is realized; the main control unit realizes real-time monitoring on the main and standby clock phase difference, the frequency difference measuring value and the main clock and constant temperature crystal oscillation phase difference measuring value, and in addition, the main clock and the standby clock are switched through control signals when the two measuring values simultaneously exceed the preset threshold values.