33results about How to "Resolve reverse recovery" patented technology

The invention discloses a resonance dead-soft switching inverter circuit applied to a brushless DC motor, comprising a DC power supply, an input voltage-dividing circuit, a control circuit and an inverter bridge. The input voltage-dividing circuit comprises two concatenated capacitors; the three poles of the converter bridge are connected to the brushless DC motor. An auxiliary resonance circuit is added between the pole of the converter bridge and the midpoint of the input voltage-dividing circuit, including 3 auxiliary two-way switches and 1 inductometer. One end of each of the 3 auxiliary two-way switches is connected to one end of the inductometer; the other end of each of the 3 auxiliary two-way switches is connected to the pole of a 3-phase converter bridge respectively; the other end of the inductometer is connected to the midpoint of the input voltage-dividing circuit. The control circuit sends out signals to control the auxiliary two-way switches and the converter bridge switching parts to switch on / off. The invention is capable to operate under multiple driving modes.

The present invention relates to an AC / DC converter (1) of the type having an AC / DC conversion stage (2) and a DC / DC conversion stage (3), the AC / DC conversion stage (2) comprising an input filter stage (4), an input rectifier stage (5) and a tracking boost converter stage. The boost converter stage in turn comprises an input choke (10), a boost diode (16) and a bulk capacitor (17). The bulk capacitor (17) is arranged to store a range of voltages substantially proportional to the input voltage of the converter. The DC / DC stage (3) is arranged to receive the range of voltages from the bulk capacitor (17) and is controllable to provide a desired DC output regardless of the voltage received from the bulk capacitor (17). This is achieved through careful combination of components and use of output feedback control to control the voltage applied to an isolated transformer (41) in the DC / DC stage.

The invention discloses a high-gain isolated type direct current-direct current (DC-DC) convertor for fuel-cell power generation and belongs to the technical field of convertors. The convertor comprises an input current multiplier, a switch capacity multiplier, a clamping circuit and a transformer. The input current multiplier comprises a first input inductor, a second input inductor, a first switch tube and a second switch tube. The clamping circuit comprises a clamping capacitor Cc, a first clamping switch tube and a second clamping switch tube. The switch capacity multiplier comprises a first resonant capacitor, a second resonant capacitor, a first output capacitor C2a, a second output capacitor C2b and four rectifier tubes. The primary side of the transformer is connected with the input current multiplier and the clamping circuit respectively, and the secondary side of the transformer is connected with the switch capacity multiplier. When high-gain isolated type DC-DC convertor is applicable to the fuel-cell power generation and grid connection, the convertor needs an occasion with high gain, small input current ripple and high efficiency, and the convertor is also applicable to other types of new energy power generation including low-output-voltage power generation and the like.

The invention provides a high voltage rise DC / DC converter. The high voltage rise DC / DC converter can convert a low voltage direct current into a high voltage direct current, can achieve soft switching, and has high work efficiency. The high pressure rise DC / DC converter comprises two portions which are respectively a boost circuit unit and a voltage rise unit. The boost circuit unit is composed of two power switches S1 and S2, and a primary side L 1 of a coupling inductor. A subsidiary side L 2 of the coupling inductor, a capacitor c and a diode D form the voltage rise unit of the high voltage rise DC / DC converter. The voltage rise unit is equivalent to a controllable direct current voltage source, and voltage of the voltage rise unit is related to turn ratios N of the subsidiary side and the primary side of the coupling inductor, and the duty ratio D of a switching tube S1. Compared with an existing high voltage rise DC / DC converter, the high voltage rise DC / DC converter is high in voltage gain, low in voltage stress of devices, and high in efficiency.

This invention discloses one resonance direct flow flexible inverter circuit, which comprises one direct current power, one control circuit, one inverter bridge and drive load, wherein, the direct current power and inverter bridge are added with aid resonance circuit composed of three aid switches, six diodes, three capacitors and one inductance; when the power parts converts from status to another one, the control circuit sends control signal for reasonable aid switch V1, V2 and V3.

The invention provides a high-efficiency high-gain DC-DC (Direct Current to Direct Current) converter with a coupling inductor. A voltage-doubled output input-stage Boost converter is formed by a direct-current power supply, a switching tube, a first diode, a second diode, a fourth diode, a fifth diode, a first inductor, a second inductor, a first capacitor, a third capacitor and a fourth capacitor; an output-stage Boost converter with coupling inductor is formed by the first capacitor, the switching tube, a third diode, a second capacitor, a fifth capacitor, a sixth capacitor, the coupling inductors and a load. The input-stage Boost converter introduces the second inductor as a resonant inductor and the output-stage Boost converter adopts the coupling inductor, so that the zero current turning-on of the switching tube is realized and the zero current turning-off of each diode is realized at the same time. The converter has the advantages that the gain is extremely high and can reach 2(2+N) / (1-D)2, and the voltage stress of the switching tube is very low and is only 1 / (2+N).

The invention relates to a three-way forward voltage output single-stage bridgeless Cuk PFC converter and a control method thereof. Compared with the traditional Cuk PFC converter, this converter completely eliminates the diode rectifier bridge, only uses a single input inductor, has a high utilization rate of the inductor, and can realize reliable three-way forward voltage output, which solves the reverse voltage output of the Cuk topology problem, and there is no cross-effect of each channel. Working in DCM mode, the input current can naturally track the input voltage to achieve unity power factor. It has the characteristics of high efficiency, high power density and high reliability.

The invention relates to a coupling inductance ZVS / ZCS double tube direct current converter with a charge pump. The coupling inductance ZVS / ZCS double tube direct current converter with the charge pump comprises a direct-current power source, a first boosting circuit, a second boosting circuit, a first charge pump boosting unit, a second charge pump boosting unit, a switch circuit and a load, wherein an output voltage of the direct-current power source is output through two paths, one path of the output voltage is input into the first charge pump boosting unit after undergoing primary boosting of the first boosting circuit and input to one end of the load through the switch circuit after undergoing secondary boosting of the first charge pump boosting unit, and the other path of the output voltage is input to the second charge pump boosting unit after undergoing primary boosting of the second boosting circuit and input to the other end of the load after undergoing secondary boosting of the second charge pump boosting unit. The circuits are small in size and high in conversion efficiency, voltage stress of power switch tubes is low, current stress of the power switch tubes is small, and conduction loss of the power switch tubes is small; zero voltage switching can be achieved, and switching loss is small; all power diodes can be switched off naturally with zero current, the reverse recovery problem does not exist, and EMI of the circuits is small.

The invention provides a DC-DC (Direct Current to Direct Current) converter with high efficiency, high gain and low voltage and current stresses. In the DC-DC converter, a direct-current power supply, a switch tube, a first diode, a second diode, a fourth diode, a fifth diode, a first inductor, a third inductor, a first capacitor, a third capacitor and a fourth capacitor construct an input-grade Boost converter; the first capacitor, the switch tube, a third diode, a sixth diode, a seven diode, an eighth diode, a ninth diode, a second inductor, a fourth inductor, a fifth capacitor, a sixth capacitor, a seventh capacitor, an eighth capacitor, a second capacitor and a load construct an output grade Boost converter. The input Boost converter and the output Boost converter are connected to the second inductor and the fourth inductor to serve as resonant inductors, so that the zero current turning-on of the switch tube is realized; meanwhile, the zero current turning-off of each diode is realized. The gain of the converter is 6 / (1-D)2, and the voltage stress of the switch tube is one third that of the output voltage.

The invention provides a high-efficiency high-gain DC-DC converter with double coupling inductors. The high-efficiency high-gain DC-DC converter with the double-coupling inductors comprises an input level Boost converter with a first coupling inductor and an output level Boost converter with a second coupling inductor. The input level Boost converter is composed of a direct-current power supply, a switching tube, a first diode, a second diode, a fourth diode, a fifth diode, the first coupling inductor, a first capacitor, a second capacitor and a fifth capacitor. The output level Boost converter is composed of a second capacitor, a switching tube, a third diode, a sixth diode, a seventh diode, a third capacitor, a fourth capacitor, a sixth capacitor, the second coupling inductor and loads. The inductors are adopted in the input level Boost converter and the output level Boost converter. Zero-current switching-on of the switching tubes is achieved, and meanwhile zero-current switching-off of each diode tube is achieved. The converter is high in gain which can reach (2+N1)(2+N2) / (1-D)2, and the voltage stress of the switching tubes is low and is only 1 / (2+N2) of the output voltage.

The invention provides a zero-current zero-voltage soft-switching Buck converter. Two buffer capacitors Cr1 and Cr2, a small inductor Lr and an auxiliary fly-wheel diode D2 are introduced into a traditional buck converter. The two buffer capacitors are connected to a main switch tube S1 and a main fly-wheel diode D1 in parallel respectively, and the small inductor Lr is coupled to the main inductor, and the diode D2 is connected to the middle of the coupling inductor. The zero-current soft-switching on and the zero-voltage soft-switching off of the main switch tube S1 can be realized. Meanwhile, the zero-current off of the main fly-wheel diode D1 and the zero-current on and off of the auxiliary fly-wheel diode D2 can be realized. By virtue of the zero-current off of the diodes D1 and D2, the reverse recovery problem of the diodes is solved. According to the converter, the relatively high efficiency of the buck converter in the full load range can be realized, so that the converter is suitable for being applied to DC-DC voltage reduction of various load ranges.

The invention discloses a PWM control method for a three-level LLC resonant converter. The LLC resonant converter at least comprises a first bridge arm which is connected with a plurality of switch tubes in series and coupled at the primary side of a transformer; the switch tubes comprise two outer tubes close to both ends of the first bridge arm and two inner tubes between the outer tubes; in the PWM mode, the duty ratio of the inner tube is maintained to be no less than the minimum duty ratio when the width modulation of duty ratio is carried out on the inner tube and the outer tube according to the gain demand; the minimum duty ratio is determined according to the requirement that the duration of delaying the turn-off of the inner tube can avoid the reverse resonance of resonance current after the outer tube is turned off. By maintaining the duty ratio of the inner tube to be no less than the minimum duty ratio, the resonance process of current of the primary side of the converter is changed, thereby avoiding generating the problem of the backward recovery of a body diode.

The invention discloses a soft switching inverting circuit and a control method thereof. The soft switching inverting circuit comprises a control circuit, a direct current power source, a partial pressure circuit and an inverting bridge, wherein a resonance auxiliary circuit is connected between the partial pressure circuit and the inverting bridge, the resonance auxiliary circuit comprises two auxiliary switches V and Tr, a single-phase inverting bridge, a capacitor Cr, a diode D and an inducer Lr, the single-phase inverting bridge consists of diodes Dr1, Dr2, Dr3 and Dr4, and the resonance auxiliary circuit is connected with the control circuit and is used for controlling the switching on and off of the auxiliary switches V and Tr according to signals dV and dTr transmitted by the control circuit; and the soft switching inverting circuit has the control method that the control circuit transmits a control signal to reasonably control the switching on and off of the auxiliary switchesV and Tr when a power device of the inverting bridge needs to be switched into another switching status from one switching status. After the invention is used, the defects that the additional cost ishigh, the control is complex, the power density of the inverter is low and the like in the prior art are overcome, the power density of the inverter is improved, the electromagnetic interference is reduced, and the control method is simple and easy to realize.

The invention provides a high-efficiency high-gain DC-DC (Direct Current to Direct Current) converter with a coupling inductor. A voltage-doubled output input-stage Boost converter is formed by a direct-current power supply, a switching tube, a first diode, a second diode, a fourth diode, a fifth diode, a first inductor, a second inductor, a first capacitor, a third capacitor and a fourth capacitor; an output-stage Boost converter with coupling inductor is formed by the first capacitor, the switching tube, a third diode, a second capacitor, a fifth capacitor, a sixth capacitor, the coupling inductors and a load. The input-stage Boost converter introduces the second inductor as a resonant inductor and the output-stage Boost converter adopts the coupling inductor, so that the zero current turning-on of the switching tube is realized and the zero current turning-off of each diode is realized at the same time. The converter has the advantages that the gain is extremely high and can reach 2(2+N) / (1-D)2, and the voltage stress of the switching tube is very low and is only 1 / (2+N).

A transfer DC-DC inverter of zero-voltage and zero-current type is prepared as forming booting DC-DC inverter by master switch tube A, power diode D and energy storage inductance L, realizing zero-voltage and zero-current on-off state of master switch tube A and realizing zero-current soft switch of auxiliary switch tubes B and C by utilizing auxiliary switch tube B to control auxiliary resonant network A and utilizing auxiliary switch tube C to control auxiliary resonant network B.

The invention discloses a high gain and high power density converter and commutation method for high and low voltage sides thereof. The high gain and high power density converter comprises a first setof coupled inductors, a second set of coupled inductors, a low voltage side circuit of the converter, and a high voltage side circuit of the converter. The high gain and high power density convertercan achieve zero voltage turning-off and zero current turning-on of all power switch tubes, which is similar to zero voltage turning-on. During the high-voltage side forward and reverse charging and discharging, a secondary side winding is shared, controllable power switch tube are used instead of forward and reverse charging diodes, and the output voltage is flexibly controlled by controlling a duty ratio of the controllable power switch tube, thereby broadening the control range and flexibility of the load output voltage; reducing circuit components, simplifying the structure, improving thepower density and reliability, and reducing costs.

The invention discloses a phase-shifting full-bridge conversion circuit, which includes a transformer; the leading bridge arm is composed of a MOS tube 1 and a MOS tube 2 connected in series, and the connection point of the two MOS tubes is connected to the primary side of the transformer through a capacitor and a resonant inductance in sequence. The capacitor and the resonant inductor are connected in series; the lagging bridge arm is composed of three MOS tubes and four MOS tubes connected in series, the connection point of these two MOS tubes is connected to the other end of the primary side of the transformer, and the input DC voltage is added between the connection point of MOS tube one and MOS tube three and the connection point of MOS tube two and MOS tube four; the output circuit is composed of four rectifier diodes and an output capacitor; the two ends of the output capacitor are output the DC voltage. The invention also discloses a control method for the phase-shifting full-bridge conversion circuit. The invention realizes the full-bridge soft switch of the phase-shifting full-bridge conversion circuit, reduces switching loss and improves the efficiency of the whole machine.