38results about How to "Suppress reverse recovery issues" patented technology

The converter includes six pieces of three phase bridge arm including full controlled main switch with diode connected in inverted parallel, input inductance connected between power source and middle point of each phase bridge arm, and output capacitance connected to output end of three phase bridge arm. Characters are that capacitance is connected to six main switches respectively. Resonant inductance is connected to DC bus of three-phase bridge arm and output capacitance. Cascaded circuit of auxiliary switch and clamping capacitance is cross-connected on two ends of resonant inductance. Two ends of the auxiliary switch are connected to diode in inverted parallel as well as connected to capacitance. Features of the converter are simple structure, restraining backward recovery of diode connected in inverted parallel, realization of soft switch and high efficiency of circuit.

The invention discloses a three-phase four-wire zero-voltage switch rectifier circuit with a balancing bridge arm, and a modulation method for the three-phase four-wire zero-voltage switch rectifier circuit. The circuit comprises a DC side load of the rectifier circuit, a DC side series capacitor, an AC side filter inductor, a balancing bridge arm inductor, and four groups of bridge arms which are composed of two full-control main switches with anti-parallel diodes. An auxiliary switch comprising an anti-parallel diode, and a resonant branch circuit composed of the clamping capacitor and a resonant inductor are connected between a DC side bus capacitor and a bus of the four groups of bridge arms. Two ends of the main switch and the auxiliary switch are in parallel connection with capacitors. According to the invention, the circuit achieves the synchronization of the pulse signals of the auxiliary switch and the main switch, can achieve the zero-voltage connection of all switches in each switching period, effectively inhibits the reverse recovery current of the anti-parallel diode of the main switch, is small in switching loss, is high in circuit efficiency, facilitates the improvement of the switching frequency, and improves the system power density.

The invention discloses a minimum-voltage, active-clamp and three-phase grid-connected inverter, which comprises a DC inverter power supply, an AC filter inductor and a three-phase bridge arm. The three-phase bridge arm consists of 6 full-control master switches with anti-parallel diodes, an auxiliary switch with an anti-parallel diode is connected between the DC inverter power supply and the DC bus of the three-phase bridge arm, the two ends of the master switches and the auxiliary switch are all connected with a capacitor in parallel, and the two ends of the auxiliary switch are bridged with a resonance branch formed by serial connection of a resonance inductor and a clamp capacitor. The inverter of the invention has simple structure and adopts an improved space vector modulation method. When the power-factor angle of the grid-connected current of the inverter is between minus 30 degrees and plus 30 degrees , the zero-voltage switching-on of all the master switches can be realized through one action of the auxiliary switch in each switching period, the reverse recovery current of the anti-parallel diodes of the master switches are inhibited, and the switch voltage stress is equal to the voltage of the DC inverter power supply. Moreover, due to the low switching loss and high circuit efficiency, the invention facilitates the improvement of the operating frequency, thereby enhancing the power density.

The invention discloses a circuit with an active power decoupling single-phase no-voltage switch inverter and a modulation method thereof. The circuit comprises a direct-current power supply, three groups of bridge arms, a filter inductor of the inverter and a power grid, a filter inductor and an energy-storage capacitor decoupled by active power, an auxiliary switch comprising an anti-parallel diode connected between the direct-current power supply and a bus of the three groups of bridge arms, a resonance branch circuit consisting of a clamping resistor and a resonance inductor, and a capacitor, wherein the three groups of bridge arms comprise two groups of full-bridge single-phase inverters and an active power decoupling group, and each group of bridge arms is composed of two full control type switches with anti-parallel diodes; and the main switch is connected with two ends of the auxiliary switch in parallel. According to the modulation method, pulse signals of the auxiliary switchand the main switch are synchronized, no-voltage switching-on of all switches can be realized in each switching period, the reverse recovery current of the anti-parallel diode of the main switch is effectively inhibited, the switching loss is little, the circuit efficiency is high, the switching efficiency is improved, and the system power density is improved.

The invention discloses a low-additional-voltage zero-voltage switch energy storage bridge type inverter and a modulation method. The low-additional-voltage zero-voltage switch energy storage bridge type inverter comprises a direct-current side storage battery, a direct-current capacitor, an alternating-current filter inductor and a single-phase bridge arm, wherein the single phase bridge arm is formed by four full-control master switches with anti-parallel diodes, a series branch of an auxiliary switch with an anti-parallel diode and a clamping capacitor is connected between the direct-current side storage battery and a direct-current bus of the single-phase bridge arm, two ends of the branch are connected with resonance inductors, and two ends of the master switches and the auxiliary switch are in parallel connection with the capacitor. The low-additional-voltage zero-voltage switch energy storage bridge type inverter can independently run with load or runs in a grid-connection mode and is simple in structure, power can flow bidirectionally to charge and discharge the storage battery, the master switch uses a sine wave pulse width modulation method, and modulation signals of the master switches are synchronous with the auxiliary switch. In one switching period, the auxiliary switch only works once to enable all master switches to achieve zero-voltage switching. Reverse recovery current of the anti-parallel diodes of the master switches can be restrained so as to be small in switching loss, high in circuit efficiency and favorable for improving efficiency to improve power density.

The invention discloses a three-phase four-wire system zero voltage switching back-to-back converter circuit and a modulation method thereof. The circuit comprises converter circuit inverter side loads, filter capacitors, filter inductors, rectifier side filter inductors, six sets of bridge arms formed by two full control main switches equipped with anti-parallel diodes, a resonance branch formedby an auxiliary switch including the anti-parallel diode and connecting between the DC bus capacitor and the six sets of bridge arms, a clamping capacitor and a resonance inductor, and resonance capacitors connected in parallel on the two ends of the main switch and the auxiliary switch. The pulse signals of the auxiliary switch and the main switch are synchronized so that zero voltage switching of all the switches can be realized in each switching period, the reverse recovery current of the main switch anti-parallel diodes can be effectively suppressed, the switching loss is low, the circuitefficiency is high, the switching frequency can be enhanced and the system power density can be enhanced.

The invention provides an additional-voltage-free zero voltage switch bridge-free power factor corrector and a modulation method. The corrector comprises a power factor corrector direct current side load, a direct current side capacitor, an alternating current filtering capacitor, a bridge arm formed by two full control main switches with antiparallel diodes and a bridge arm formed by connecting two diodes in series. An antiparallel diode auxiliary switch is connected between bridge arm side direct current buses formed by directly connecting the direct current side capacitor and the diodes. Capacitors are arranged at two ends of the main switches and the auxiliary switch in parallel, capacitors are connected at two ends of the diodes on the bridge arm in parallel, and resonant branches formed by connecting resonant inductors and clamping capacitors are in bridge joint with two ends of the auxiliary switch. The main switches adopt the sine wave pulse width modulation method, and demodulation signals of the auxiliary switch are synchronous with those of the main switches. The corrector is simple in structure, and the direct current output can serve as a direct current power supply in use. The corrector is small in switch consumption, high in circuit efficiency and favorable for improving working efficiency and further improves power accuracy.

The converter includes rectification circuit, inductance, diode and main switch. Main structure of the converter is as following: main switch is connected to first capacitance in parallel, and diode is connected to second capacitance. One end of inductance is connected to output end of rectification circuit, and the other end of inductance is connected positive end of the diode. Cascaded circuit of main switch and resonant inductance is connected between connection point of inductance and diode and another output end of rectification circuit. Cascaded auxiliary switch and clamping capacitance is cross connected on two ends of resonant inductance. Two ends of the said auxiliary switch are connected to third capacitance etc. Features are: simple structure, restraining backward recovery of diode connected in inverted parallel, realization of soft switch and high efficiency of circuit. The converter is applicable to preceding stage of rectifier unit in distribution power source.

The invention provides an energy-storage half-bridge type inverter of a low-additional-voltage zero-voltage switch and a modulating method. The energy-storage half-bridge type inverter comprises a direct-current side storage battery, direct-current side partial-pressure capacitors, an alternating-current side filter inductor and a single-phase bridge arm, wherein the single-phase bridge arm comprises two full-control main switches with anti-parallel diodes. A serially connected branch circuit of an auxiliary switch with an anti-parallel diode and a clamping capacitor is connected among the direct-current side partial pressure capacitors and a direct-current bus of the single-phase bridge arm, a resonance inductor is connectively crossed at two ends of the branch circuit, and two ends of the main switches and the auxiliary switch are connected with the capacitors in parallel. The energy-storage half-bridge type inverter runs with load independently or in a grid connection manner, the main switches adopt a sine wave pulse width modulation method, and modulation signals of the auxiliary switch are synchronous with those of the main switches. The auxiliary switch only acts once in each switch period so that zero-voltage conducting of all the main switches can be realized, reverse restoration current of the anti-parallel diodes of the main switches is suppressed, voltage stress of the switches is equal to the voltage of the direct-current side of the inverter, the loss of the switches is low, circuit efficiency is high, work frequency is improved and power density is improved.

The invention discloses a bidirectional zero-voltage switch modulation method of a single-phase DC-AC converter. The modulation method comprises the steps of judging a current converter working mode according to a product of a voltage and a current of a power grid; inputting a modulation wave subjected to sine pulse width modulation after full-wave rectification to a forward or reverse zero-voltage pulse module by a selective switch; selecting a forward zero-voltage pulse module when the converter works in an inversion mode; selecting a reverse zero-voltage pulse module when the converter works in a rectification mode; inputting the modulation wave to the forward or reverse zero-voltage pulse module and then generating a bridge arm short-circuit signal and an auxiliary switch signal; and acting the short-circuit signal onto a main switch during conversion period of the converter, and providing a freewheeling loop for magnetization of a resonant inductor so as to provide enough resonantenergy. The converter is simple in structure, zero-voltage connection of all switch devices in inversion and rectification modes are achieved, the switch loss is low, the circuit efficiency is high,a diode can be prevented from being reversely recovered, and the electromagnetic interference is reduced.

The invention discloses a two-stage three-phase soft-switching current transformer which comprises a front-stage DC/DC transformer and a rear-stage three-phase DC/AC transformer. A resonant branch composed of an auxiliary switching tube having an anti-parallel diode, a clamp capacitor and a resonant inductor is connected between a positive common bus of the front and rear stages and an intermediate DC-side capacitor. A resonant capacitor is connected in parallel with main switching tubes and the auxiliary switching tube. The auxiliary switching tube is synchronized with the driving pulse signals of the main switching tubes in the current transformers in the front and rear stages, so as to realize zero-voltage turning-on of all the switching tubes in each switching period, and suppress thereverse recovery current of the anti-parallel diodes of the main switching tubes. The two-stage three-phase soft-switching current transformer is low in switching loss, high in circuit efficiency, andcontributes to increasing the switching frequency and increasing the system power density.

The invention discloses a unified power quality regulator based on a soft switching circuit. At an input side, three half-bridge arms form a three-phase current converter circuit, which is connected in series with a three-phase power grid through an LC filter and a transformer. At an output side, the other three half-bridge arms form a three-phase current converter, which is connected to a power grid at a load end through an output filter inductor. Each half-bridge arm is composed of two main switch transistors connected in series in the vertical direction. A resonant branch consisting of an auxiliary switch transistor, a clamping capacitor, and a resonant inductor is connected between the positive and negative common buses of the six half-bridge arms. Resonant capacitors are connected inparallel with the main switch transistors and the auxiliary switch transistor. The driving pulse signal of the auxiliary switching transistor is synchronized with the driving pulse signal of the mainswitching transistor. The unified power quality regulator can realize zero-voltage turning on of all switching transistors in each switching period, suppresses the reverse recovery current of the mainswitch anti-parallel diode, is low in switching loss and high in circuit efficiency, contributes to increasing the switching frequency and increases system power density.

The invention provides a single-phase power input circuit based on a three-phase Vienna PFC topology and a control method. Through the adjustment of the duty ratio of a corresponding switching tube suspended in the three-phase Vienna PFC topology, the reverse recovery problem of a low-frequency device in the bidirectional switch is suppressed, the reverse recovery loss of the low-frequency devicein a bidirectional switch of the three-phase Vienna PFC topology is reduced, the heating of the three-phase Vienna PFC topology is reduced, and a solution is provided for the reliable operation of thethree-phase Vienna PFC topology during single-phase power or direct-current input.

The converter includes rectification circuit, inductance, diode and main switch. One end of inductance is connected to output end of rectification circuit, and the other end of inductance is connected positive end of the diode. Cascaded circuit of main switch and resonant inductance is connected between connection point of inductance and diode and another output end of rectification circuit. Cascaded circuit of resonant inductance and clamping capacitance is cross connected on two ends of resonant inductance. Two ends of the said auxiliary switch are connected to third capacitance etc. Output capacitance is connected between negative diode and other output end of the rectification circuit. Features are: simple structure, restraining backward recovery of diode connected in inverted parallel, realization of soft switch and high efficiency of circuit. The converter is applicable to preceding stage of rectifier unit in distribution power source/

The invention relates to a boost conversion circuit, which comprises a three-winding coupling inductance boost unit and an output unit, and is characterized in that the three-winding coupling inductance boost unit is used for controlling a controllable switch unit in the three-winding coupling inductance boost unit to act according to a boost control signal so as to boost the voltage of a standby power supply of a power grid to a first voltage of a preset voltage value; and the output unit is connected with the three-winding coupling inductance boosting unit and is used for generating stable second voltage according to the first voltage. According to the boost conversion circuit, the three-winding coupling inductor is arranged, the parameter turn ratio is introduced for the boost conversion circuit, high gain can be achieved by adjusting the turn ratio, meanwhile, the limit duty ratio is avoided, in addition, the leakage inductance of the three-winding coupling inductor can restrain the reverse recovery problem of the output diode, and the output voltage of the boost conversion circuit is improved. In addition, in the boost conversion circuit, the controllable switch unit can realize zero-voltage switching, so that the switching loss of the switch tube is reduced, and the efficiency of the conversion circuit is improved.