529 results about "Soft switching" patented technology

The invention relates to the technical field of flexible direct-current power transmission, in particular to a centralized local energy storage modular multilevel converter MMC-CLES topology which comprises three phase units, each phase unit comprises an upper bridge arm and a lower bridge arm, and each upper bridge arm and each lower bridge arm comprise a bridge arm reactor arranged at one end, close to a power grid, of the bridge arm; a plurality of identical sub-modules SM which are connected to a power grid through a bridge arm reactor; the upper bridge arm and the lower bridge arm form a symmetrical structure; an energy storage sub-module is arranged at the position where the three-phase unit is directly connected with the direct-current bus. According to the invention, the control system is simplified, and the hardware cost and the control complexity are reduced. Voltage stress and current stress are smaller, higher power can be borne, and the high-power capacitor is suitable for being applied to high-power occasions. And moreover, due to the symmetrical layout, the control method is relatively simple, soft switching can be realized, and the power divider can be used as a multi-port component unit.

The invention discloses a multi-objective optimization method and system for dual active bridge circuit expansion phase shift modulation, and the method comprises the steps: calculating a voltage matching ratio, and determining an external phase shift angle ratio based on a difference value between an output voltage and an output voltage reference value; according to the voltage matching ratio and the external phase shift angle ratio, obtaining an internal phase shift angle ratio of the primary side full bridge through an offline lookup table; calculating the maximum transmission power of the dual-active bridge converter, and determining a current working mode from the six preset working modes based on the size relationship between the inner phase shift angle ratio and the outer phase shift angle ratio; generating an optimal modulation strategy through a multi-objective optimization algorithm by taking the current effective value and the current peak value as optimization objectives and combining the voltage matching ratio and the periodic parameters of the current working mode; and generating a trigger signal of each switch tube of the dual-active bridge converter. Through six-mode working area division, complete differential algorithm boundary constraint and off-line-on-line collaborative optimization, the contradiction between the current stress and the soft switching range of the converter under extended phase shift modulation is solved.

The invention discloses a soft switching modulation method and system for minimum current stress in a full power range. The system comprises an expansion phase shift optimization unit, an in-loop direct power control unit and a cooperative control unit. The in-loop direct power control unit is used for obtaining dynamic correction power, the expansion phase shift optimization unit is used for generating a phase shift ratio combination [D1, D2] which simultaneously meets the minimum current stress and the ZVS condition, and the cooperative control unit generates a PWM driving signal according to the generated phase shift ratio combination [D1, D2] to achieve soft switching control. According to the invention, the problem of current stress minimization in a wide voltage range can be effectively solved, the problem of ZVS loss in a light-load working condition can be prevented, and a load / voltage sudden change condition can be coped with in time; through the design of the ZVS boundary guarantee, the method is especially suitable for scenes needing wide voltage range efficient energy transmission, such as new energy grid connection and electric vehicle charging.

The invention discloses a soft switching HERIC non-isolated inverter and a modulation method thereof, and belongs to the technical field of inverters, the inverter comprises a bridge arm circuit, a clamping circuit, a resonance circuit, a voltage stabilizing circuit and a filter circuit, the resonant circuit comprises a first auxiliary switch tube, a second auxiliary switch tube, a third auxiliary switch tube, a fourth auxiliary switch tube, a first resonant inductor, a second resonant inductor, a first resonant capacitor and a second resonant capacitor; all high-frequency switches realize zero-current turn-on and turn-off at the same-direction stage of the voltage and the current of the power grid through the resonance circuit; all the high-frequency switches also realize zero-current switching on and switching off in the voltage and current reverse phase of the power grid; according to the modulation method, unipolar PWM modulation is adopted, the grid-connected current harmonic distortion rate is reduced, the grid-connected electric energy quality is improved, and the application value and prospect are huge.

The invention relates to an external phase shift angle determination method and system, a frequency conversion phase shift control method and a chip, and the method comprises the steps: obtaining an external phase shift angle based on a general solution of a time domain differential equation of a resonant inductor current and a resonant capacitor voltage of a DBSRC equivalent circuit and the symmetry of the DBSRC equivalent circuit; determining a first current value of the resonant inductor at the first moment and a second current value of the resonant inductor at the second moment; based on the first current value when the primary bridge circuit meets the ZVS soft switching requirement, obtaining a first relational expression of the external phase shift angle about the input voltage and the output voltage of the DBSRC and the switching frequency of the switching tube; based on a second current value when the secondary-side bridge circuit meets the ZVS soft switching requirement, obtaining a second relational expression of the external phase shift angle with respect to the input voltage, the output voltage and the switching frequency; according to the first relational expression, the second relational expression and the steady-state voltage value of the output end of the DBSRC, the expression of the external phase shift angle about the switching frequency, the steady-state voltage value and the input voltage is determined; the scheme is simple, the accuracy is high, and the portability is high.

The invention provides a simulation method and system with controllable split-phase voltage drop time difference, and relates to the technical field of electric power testing, and the method comprises the steps: adjusting voltage through a three-phase voltage regulator, employing a bidirectional silicon controlled rectifier and IGBT hybrid switch structure to achieve voltage drop, collecting and processing a three-phase voltage signal through a digital signal processor, and extracting zero crossing point information; and a control pulse signal with phase compensation is generated, the conduction time sequence of the switch element is controlled to realize soft switching, and the industrial computer receives and processes the signal and displays a voltage drop waveform. The split-phase voltage drop time difference can be accurately controlled, and the simulation precision and the system reliability are improved.

The invention discloses a multi-motor dynamic synchronous regulation and control method based on virtual line shaft state feedback, and the method comprises the steps: constructing a multi-motor virtual line shaft control model, setting an expected traction torque value through the output of a virtual main shaft, and setting each physical motor as a following motor; according to the collected state data of each motor, performing joint probability modeling on the state and disturbance of each motor by adopting a preset modeling method, and generating an estimated mean value and a covariance of each motor state; designing a nonsingular terminal sliding mode surface and calculating a control signal; setting a soft saturation buffer area range, constructing a soft switching function, carrying out buffer correction on the control signal, and outputting a corrected control signal; and synchronous control of multi-motor traction output is realized according to the correction control signal. According to the multi-motor dynamic synchronous regulation and control method, the synchronous stability, the anti-interference capability and the output smoothness in a complex dynamic environment can be improved.

The present invention discloses a method for siting and sizing a flexible soft switch of a distribution network based on mixed second-order cone programming, including: acquiring interconnected flexible distribution system data; establishing and optimizing, based on the interconnected flexible distribution system data and an interconnected flexible distribution system constraint, a flexible soft switch siting and sizing model with a minimal daily comprehensive operation cost as an objective; and acquiring an optimal flexible soft switch siting and sizing solution by using combination of an improved sparrow algorithm and second-order cone programming to solve. The present invention is both reliable and economic.

The present application provides an on-board charger and a control method thereof. Since the transformer side of the AC / AC conversion circuit is connected to the AC side of the AC / DC conversion circuit via a transformer, the on-board charger has a single-stage structure. Furthermore, since the instantaneous sampling value of the grid-side current is equal to its instantaneous reference value when stable, and the instantaneous reference value of the grid-side current is determined by the phase of the instantaneous sampling value of the grid-side voltage and the reference peak value of the grid-side current, the on-board charger has a PFC function. Furthermore, since the battery-side charging power can be indirectly controlled by controlling the grid-side current, the on-board charger has a battery-side voltage and current control function. Furthermore, since phase shift control is performed on the two conversion circuits, and the phase shift control enables soft switching of the power devices in the two conversion circuits, and the single-stage structure reduces the current flowing through the devices, efficiency is improved. Therefore, the single-stage structure efficiently implements the PFC and battery-side voltage and current control functions of the two-stage isolated on-board charger.

The invention belongs to the technical field of power electronics, and discloses a global efficiency optimization-based four-switch Buck-Boost + LLC integrated topology modulation method, which comprises the following steps of: determining an optimal working point under a specified working condition point through three constraint conditions of gain, soft switching and loss according to three degrees of freedom, namely two duty ratios d1 and d2 and a phase shift angle phi; and pulse width modulation and phase shift modulation are carried out on the integrated topology. Correspondingly, the invention provides a controller which is used for executing the specific steps of the modulation method of the four-switch Buck-Boost + LLC integrated topology based on global efficiency optimization in the invention. According to the modulation strategy provided by the invention, the loss of the four-switch Buck-Boost + LLC integrated topology in a wide input range can be reduced while soft switching in a full-load range is ensured, and an external circuit does not need to be additionally arranged, so that the integrated topology has high power density and high efficiency.

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 invention discloses an intelligent soft switching and multilayer electro-hydrogen hybrid energy storage two-stage space-time decoupling configuration method and system. The method comprises the following steps: inputting basic data and initializing network basic parameters; in the first stage of constructing the two-stage MEH-SOP model, the power / capacity of each device of the MEH is optimally configured on the basis of annual 8760h time sequence operation simulation considering time-of-use electricity price; constructing a second stage of the two-stage MEH-SOP model, extracting typical scenes of MEH full-year high-power charging / discharging and power distribution network full-year voltage serious out-of-limit, and optimally configuring SOP multi-port capacity; and solving the constructed two-stage MEH-SOP model, and outputting an optimal configuration result. According to the invention, a multi-level energy storage system covering from the day to the week is constructed, and the multi-port SOP direct current side is connected in a modularized manner, so that the structural flexibility and the operation flexibility of the power distribution network are remarkably enhanced.

The application discloses a single-stage bidirectional power conversion topology structure capable of realizing wide-range soft switching and a control method thereof. The bridge-in and bridge-between phase shift control of a double half-bridge circuit and a high-frequency switch matrix provides a basis for realizing soft switching of all power tubes. The soft switching of a wide voltage variation range is realized by real-time adjustment of a switching frequency according to the size of a port voltage. The bridge arm current connected with the primary side of a second transformer is the sum of the primary side current of the second transformer and the inductance current connected with the primary side of the second transformer in parallel. By designing the inductance value of the parallel inductance connected with the primary side of the second transformer, the bridge arm current connected with the primary side of the second transformer can be effectively changed, so that the soft switching realization range of the switching tube of the bridge arm connected with the primary side of the second transformer under the wide power transmission range can be expanded.

The invention provides a bypass switch switching control method suitable for the charging and discharging process of a series battery pack system, and the method comprises the steps: obtaining the voltage and current information of each battery unit, and judging the charging and discharging states of the battery units; for a battery unit in a charging or discharging state, if the voltage of the battery unit reaches a preset charging cut-off voltage, a switch A connected in series with the battery unit is controlled to be switched off step by step, and meanwhile, a switch B connected in parallel with the battery unit is controlled to be switched on step by step, so that bypass of the battery unit is realized; in the process of controlling the switching of the switch A and the switch B, the on-resistance of the switch A and the switch B is adjusted, so that the current flowing through the switch-off switch is gradually reduced to zero, the current flowing through the switch-on switch is gradually increased, the total current of the switch A and the switch B is kept constant, the total current is the charging current of the system, and the soft switching of the bypass switch is realized; the charging and discharging process of the battery pack is kept continuous, so that the working stability of the whole system is realized.

The invention discloses an OLTC topological structure of an electronic soft switching technology and a driving method. In the topological structure, a power supply is connected with a first transformer, the first transformer is connected with a second transformer, and the second transformer is connected with a load; a low-voltage winding of the first transformer is connected with a plurality of taps; the fixed end of the low-voltage winding of the first transformer and each tap are connected with one end of an independent mechanical switch; according to an interval connection mode, the other ends of all the mechanical switches are connected to form two series switch loops, and each series switch loop is connected with an independent electronic change-over switch to form two series circuits; the two electronic change-over switches are connected in parallel, and the second transformer is connected into a series circuit controlled by the two electronic change-over switches respectively. The mechanical switch and the electronic change-over switch are jointly used, so that short-circuit current and surge voltage cannot be generated when the electronic change-over switch performs state switching, and the quality of output voltage waveforms is improved.

The invention discloses a control method for improving the heavy load efficiency of an asynchronous parallel soft switching inverter, and the method comprises the following steps: S1, constructing a topological structure of the asynchronous parallel inverter, generating a DPWM modulation wave through zero-sequence component injection in a QCM mode, and enabling a power tube not to act in a specific interval in a fundamental wave period; s2, adjusting a clamping interval of a DPWM1 strategy by correcting the injected zero-sequence component; s3, calculating a phase shift angle, and generating carrier waves of a leading bridge arm and a lagging bridge arm; s4, when the power tube enters or exits from the non-action interval, transition interval control is carried out, so that the differential mode inductance circulating current is reduced to 0; and S5, generating a driving signal of a hybrid control strategy based on DPWM modulation, and controlling a switching tube to act according to the optimized clamping interval and transition logic. According to the method, the current stress and on-state loss of the power tube of the asynchronous parallel inverter under the heavy load are reduced, and the current stress minimization of the power tube and the efficiency maximization of the inverter are realized.

The invention relates to a dual-active bridge converter backflow power and soft switching range coordinated optimization control method, which widens the soft switching range of a dual-active bridge under full power on the premise of keeping the lowest backflow power, thereby improving the converter efficiency under a high switching frequency scene. According to the scheme, an optimization mapping relation of combination of different optimization input parameters k and output shift phases is given, so that control and implementation are facilitated.

The invention relates to an intelligent energy storage soft switching configuration method considering refined photovoltaic power generation potential evaluation. The method comprises the following steps: constructing a photovoltaic power generation potential evaluation model based on a physical model chain; constructing an intelligent energy storage soft switch model; and configuring the obtained intelligent energy storage soft switch model. An energy storage device is integrated to a direct current port of an SOP, an intelligent energy storage soft switching device model is constructed, a power distribution network has space-time flexible adjustment potential, an intelligent energy storage soft switching configuration method considering photovoltaic power generation potential evaluation is provided, a space power transfer-time energy scheduling two-dimensional cooperation mechanism of an E-SOP is utilized, and the power distribution network is optimized. And the energy production and elimination among the regions are balanced, so that the random fluctuation of the source and load sides of the power distribution network can be better relieved.

The present invention proposes a method for implementing continuous current soft switching of a switched inductor battery balancer. The method is divided into three cases according to the voltage of the battery cells being balanced, namely, no balancing is required between the battery cells, battery cell B1 transfers energy to battery cell B2, and battery cell B2 transfers energy to battery cell B1. The signal is modulated according to the modulation ratio to obtain a PWM signal for controlling the first switch tube S1 and the second switch tube S2. The method of the present invention can realize soft switching of all the switch tubes in the balancer, reduce the loss of the balancer, and improve the efficiency. In addition, the control of the balancer does not require the participation of the current feedback signal, eliminates the current sensor, saves the cost of the balancer, and thus greatly improves the market competitiveness of the switched inductor lithium-ion battery balancer.

The invention discloses a leakage current suppression method and circuit for a soft switching grid-connected inverter, and belongs to the technical field of power electronic converters, and the method comprises the steps: building a space voltage vector according to a three-phase voltage, building a three-level vector space in a complex plane, and dividing sectors; defining boundary conditions, and dividing each sub-sector into six small sectors according to the boundary conditions; determining a small sector where the reference voltage vector is located according to the boundary condition and the reference vector; determining a five-segment basic vector action sequence according to the small sector where the reference voltage vector is located; according to the basic vector action sequence, boundary switching frequencies in the non-clamping two phases are obtained, and the minimum value of the boundary switching frequencies in the non-clamping two phases is selected as a unified switching frequency; and modulating the three-phase modulation wave, the unified switching frequency and the DC voltage sampling value, and outputting a pulse width control signal of each power switch tube. According to the invention, a low common-mode voltage change rate and wide-range soft switching of the power switch tube are realized, and leakage current can be effectively suppressed.

A method for optimizing an inverter for soft switching according to at least some example embodiments includes calculating efficiency values of the inverter based on a plurality of possible resonant inductance values and a plurality of possible resonant capacitance values, calculating change of voltage over time values of the inverter based on the plurality of possible resonant inductance values and the plurality of possible resonant capacitance values, and selecting a resonant inductance value of the plurality of possible resonant inductance values and a resonant capacitance value of the plurality of possible resonant capacitance values based on the calculated efficiency values of the inverter and the calculated change of voltage over time values.

The invention relates to the technical field of power electronics, in particular to a power converter and a control method thereof. The power converter comprises a primary side bridge arm, a secondary side bridge arm, a resonance circuit connected between the primary side bridge arm and the secondary side bridge arm, and a controller connected with the primary side bridge arm and the secondary side bridge arm. The controller is used for controlling an absolute value of a current angle of the resonant cavity to be smaller than or equal to an absolute value of a first phase shift angle between the primary side bridge arm and the secondary side bridge arm so as to realize soft switching of switching tubes in the primary side bridge arm and the secondary side bridge arm; the resonant cavity current angle is the phase difference between the resonant cavity current and the bridge arm output voltage of the primary side bridge arm, and the polarity of the resonant cavity current angle is the same as that of the first phase shift angle. The soft switching of the switching tubes in the primary side bridge arm and the secondary side bridge arm can be ensured, and the power converter can work in the optimal state under different working conditions.

The invention provides a fixed-frequency inductive-current-sensor-free four-switch buck-boost soft switching control method, which comprises the following steps of: generating a regulating variable based on a deviation between an output voltage and a reference value, and determining a time sequence parameter of each stage of the period; charging and discharging in opposite directions are carried out on output junction capacitors of two switch elements of the same bridge arm by utilizing inductive current in a commutation dead zone; when it is detected that the duration of the free circulation stage of the current period does not exceed a preset lower limit, adjusting the time sequence of at least one stage to execute power expansion under a fixed switching frequency, and meanwhile, keeping on under a zero voltage condition; identifying a bias component of the inductive current based on indirect characterization of the output current to the inductive current, and performing correction by adjusting a timing sequence of at least one stage; and combining the outputs of the time sequence generation, the power expansion and the offset correction obtained in the previous steps into a time sequence parameter of the current period. According to the method, the microgrid conversion requirements of a wide voltage adaptation scene on high efficiency, high power density and high robustness are effectively met.

The invention discloses a trapezoidal wave current soft switching method of an interleaving DC-DC converter, which is used for a two-phase interleaving bidirectional DC-DC converter based on a coupling inductor and a multi-phase interleaving converter thereof, and is characterized in that an inductive current adopts a trapezoidal wave mode, so that the converter works in an approximate critical conduction mode; a fixed switching frequency control or hybrid control method is adopted, so that the device can work in a Buck mode and can also work in a Boost mode. The method for realizing the soft switching is characterized in that the parasitic capacitance or the external resonant capacitor of the switching tube is discharged to be zero under the resonance action of the inductor and the capacitor in the dead zone time when the upper bridge arm switch and the lower bridge arm switch are alternately switched on, so that the zero-voltage switching-on of all the switching tubes is realized. And each phase current sharing control is adopted in the multi-phase interleaving parallel topological structure. According to the invention, the problems of large current peak value and high turn-off loss of a traditional triangular wave current mode are solved, the output ripple current is reduced, a soft switching method is provided, the switching loss is reduced, and the conversion efficiency of the converter is improved.

The invention discloses a power modulation method, system and device for an isolated single-phase DC-AC converter and a medium, and the method comprises the steps: firstly, carrying out the sampling of input and output voltage and current, and obtaining the size of transmission power; then determining the soft switching current of the primary and secondary side switching tubes; determining inner and outer phase shift angles according to the soft switching threshold current; calculating a switching frequency based on the transmission power; determining dead zone time of a primary side bridge arm and a secondary side bridge arm according to the phase shift angle, the switching frequency and a soft switching constraint condition; and finally generating a PWM driving signal. According to the invention, ZVS soft switching of all switching tubes on the DC side and the AC side can be realized, loss caused by operation of the switching tubes in the fourth quadrant in the dead zone time is optimized, the working operation efficiency of the converter is improved, the power control strategy is simple, and the method has high practical application value.

The invention discloses a bilateral variable duty ratio phase shift modulation method for a dual-active bridge converter, and belongs to the technical field of converter phase shift modulation. The invention aims to solve the problem that an existing asymmetric duty ratio phase shift modulation strategy is difficult to consider current performance and soft switching range optimization at the same time. Comprising the steps that variable duty ratio modulation is adopted for all switching tubes of the dual-active bridge converter, and trigger signals of the switching tubes on the same bridge arm are complementary; according to the unequal relation among D0, D1 and D2, selecting a mode 1 to a mode 3 with the duty ratio of Q1, Q3, Q5 and Q7 being less than 50% for modulation; determining a per-unit value expression of a current peak-to-peak value of the inductor L based on the D0, the D1 and the D2, and optimizing the current peak-to-peak value by taking the per-unit value of the current peak-to-peak value as an optimization target and combining the per-unit value of the transmission power and constraint conditions of the D0, the D1 and the D2; and obtaining optimal solutions of D0, D1 and D2, and carrying out phase shift modulation on the dual-active bridge converter based on the optimal solutions. The method is used for phase shift modulation of the dual-active bridge converter.

The invention discloses a gallium nitride soft switching high-voltage Buck voltage converter, belongs to the technical field of switching power supplies, and solves the problems of large device switching loss, high thermal stress, large voltage peak and high-frequency oscillation caused by a switching capacitor link in a traditional high-voltage Buck switched capacitor voltage converter by introducing an auxiliary soft switching link. The efficiency and the reliability of the system are improved; furthermore, by introducing a double-phase interleaving parallel structure, the current output capability of the power supply is improved, and the application in a higher power scene can be realized; meanwhile, by adopting the gallium nitride transistor, compared with the traditional scheme, the switching frequency is improved, the size of a passive element is reduced, the integration level of a PCB is improved, the parasitic parameters of the system are reduced, the dead time and the duty ratio loss are reduced, and the system efficiency and the power density are further improved.

The application provides a driving method of an inverter bridge, a driving circuit, a servo driver and a motor device. In the driving method of the inverter bridge, voltage vector output time and dead time are set, so that a power switch tube of a jth bridge arm is kept in a conduction state in two adjacent voltage vector output times before switching, the power switch tubes kept in the conduction state are changed in turn and staggeredly, in each dead time, two other power switch tubes kept in the conduction state in a previous voltage vector output time are switched off, the corresponding switching bridge arm and winding complete resonance work, the end voltage of the power switch tube to be turned on is clamped to zero potential, zero voltage conduction is realized, a soft switching mode is formed, and the switching loss is reduced and the power conversion efficiency is improved.

The invention relates to a streaming voice service concurrent processing method based on soft switching, and the method comprises the steps: building and maintaining a global voice recognition channel with an ASR server, continuously forwarding a user voice stream to the ASR server during a whole session period, and receiving a recognition result; processing the recognition result by adopting a finite-state machine and a large language model to generate a response text for multiple rounds of dialogues; and concurrently executing TTS processing while the global speech recognition channel is continuously operated: segmenting a response text into a plurality of segments according to semantics to perform streaming speech synthesis, and immediately sending a pseudo response after receiving first speech data so as to trigger a soft switch system to pre-load a playing buffer area in advance. Through global reception and concurrent processing, smooth multi-round dialogues which can be interrupted at any time are realized, and the interaction delay is reduced from a second level to a millisecond level by using a text fragmentation and early media triggering technology, so that the user experience and the interaction efficiency of an intelligent call center are remarkably improved.

The invention provides an X-ray machine power supply output current adjusting method and device, and relates to the field of medical power supplies. The method comprises the following steps of: controlling a switching tube to complete inversion by using symmetrical PWM (Pulse Width Modulation), and obtaining stable DC (Direct Current) output by completing DC / DC (Direct Current / Direct Current) conversion; compared with a traditional half-bridge circuit, a symmetrical PWM control mode is adopted; a branch composed of a diode and an auxiliary switch tube is added to the circuit. The main switch not only can well realize soft switching, but also works in a symmetrical state; the auxiliary switch tube realizes ZVS and ZCS conduction; according to the invention, soft switching of the power device is realized, and the device is small in stress and high in reliability.