42results about How to "Eliminates voltage spikes" patented technology

A passive clamping single-phase single-grade bridge type power factor correcting convertor and control method thereof belongs to the technical field of power and electron. The invention aims at solving the problems of large power frequency ripples at the output side, and slow circuit response speed of the existing single-grade power factor correcting circuit as well as the problem of generating voltage peak caused by the leakage inductance of a transformer when the transformer is employed to carry out electronic isolation on the input and output. The single-phase input rectification circuit of the invention converts an inputted single-phase alternating current into a direct current; an output bus is connected with a boost inductor, four switch pipe composition bridge structures, a diode and a clamping capacitance; the outgoing lines of the two bridge arm central points of the four switch pipe composition bridge structures are connected with a high-frequency transformer; the lateral sides thereof are connected with a single-phase output rectification circuit; the output end of the single-phase output rectification circuit is connected with an output filter capacitance and a load inparallel; in a switch period, the straight arm conducting and the aligning arm conducting of the switch pipes control alternatively. The invention is used for correcting the power factors.

The embodiment of the invention discloses a DC-DC converter filtering device. One end of the filtering device is connected to a switching node of the DC-DC converter, and the other end of the filtering device is grounded. The filtering device is used for eliminating a peak voltage generated on the switching node of the DC-DC converter. The embodiment of the invention also discloses a terminal anda DC-DC converter filtering method at the same time.

The invention provides a multi-stage SiC-MOSFET drive circuit and a control method. The multi-stage SiC-MOSFET drive circuit comprises an SiC-MOSFET, a first-stage drive circuit, a detection circuit, a second-stage drive circuit and a control circuit of the second-stage drive circuit, wherein the first-stage drive circuit is used for providing drive current to turn on the SiC-MOSFET to work; the detection circuit is used for collecting voltage dynamic waveforms in the turn-on process of the SiC-MOSFET; the control circuit comprises a waveform shaping module, a counting module and a control module which are in signal connection in sequence; the control circuit comprises a waveform shaping module, a counting module and a control module which are in signal connection in sequence. According to the invention, rapid switching-on of the SiC-MOSFET is realized through the two-stage driving circuit, the voltage peak during switching-on is eliminated, and the voltage oscillation during switching-off is reduced; and voltage dynamic parameters in the opening process are obtained, and then the secondary driving circuit is adjusted through the control module to supplement the driving current, so that stable driving voltage is provided.

The invention relates to a DC motor soft starter supplied with power by a storage battery, which has high accuracy, adjustable starting time and frequency, automatic voltage stabilization, no starting current impact, energy conservation and no phenomenon of contact sintering, and does not affect the normal work of other loads. The DC motor soft starter comprises an LCD display and keyboard module, an integrated control module and a DC motor power supply box, wherein the integrated control module is connected with the DC motor power supply box, and the LCD display and keyboard module is in two-way communication with the integrated control module; the integrated control module comprises a microcontroller module, a voltage-current signal sampling module and an IGBT driving module, wherein the voltage-current signal sampling module is used for sampling the voltage and the current of the DC motor power supply box and an absorbing circuit in real time and sending the samples into the microcontroller module; the microcontroller module is sequentially connected with a PWM auxiliary circuit, a driving circuit and the IGBT driving module, and the IGBT driving module is connected with the absorbing circuit and the DC motor power supply box; the driving circuit is connected with the absorbing circuit which is connected with the microcontroller module; and a power supply device is used forsupplying power for the modules.

The invention discloses an active clamp non-electrolytic capacitor LED driving power supply, comprising an AC input power supply, an input filter part, a rectifier part, a clamp circuit, a flyback converter, an output filter capacitor Co, a parallel absorption circuit and an LED load; The input filter part is composed of input filter inductor and input filter capacitor; the rectifier part is composed of four switch tubes; the clamping circuit is composed of switch tubes S 2 and the clamping capacitor C aux The flyback converter consists of a flyback transformer, a switch tube S 1 and diode D s Composition; the flyback transformer includes the primary winding and the secondary winding, and the primary winding includes the main inductance L m and leakage inductance L r , the primary winding is connected to the input, and the secondary winding is connected to the output; the parallel absorption loop includes the boost inductor L b , switch tube S 3 , switch tube S 4 and storage capacitor C ds . The present invention introduces an active clamp circuit to reduce the switch tube S 1 switch stress; switch tube S 1 and switch tube S 2 Both realize soft switching, reducing switching loss; at the same time, leakage inductance energy can be fed back.

This DC converter belongs to the energy converter and consists of the DC power supply (Vin), two inverter bridge arms, the resonance inductance, the isolation transformer and the rectifier / filter circuit. Its character lays on that; there is an auxiliary winding (n3) in the isolation transformer beside the primary and the secondary windings (n1, n2). One end of n3 is connected to n1 and to two clamp diodes from the joint point to form a clamping circuit. Another end of n3 is connected to the resonance inductance. This converter realizes the zero voltage switching on the rectifier. This can eliminate the voltage oscillation induced by the reverse restoration of the output rectifier. It decrease the voltage stress across the output rectifier and reduces rapidly and effectively the currents through the clamping diodes. All these raise the conversion efficiency and improve the work condition of clamping diodes during light load.

The invention discloses a parallel resonant zero-voltage switch push-pull forward converter. The main circuit of the converter includes a primary circuit and a secondary circuit; the primary circuit is provided with a resonant inductor and a parallel resonant capacitor. Through the resonance of the resonant inductance and the parallel resonant capacitor, the zero-voltage switch of the main power transistor in the primary side circuit is realized. The converter can eliminate the voltage peak of the main power tube, improve the EMC effect, increase the boosting capability and conversion efficiency. The circuit of the invention has the advantages of simple structure, convenient control and reliable operation.

A novel unipolar frequency doubling SPWM modulation method for a single-phase high-frequency chain matrix rectifier. The topology of the single-phase high-frequency chain matrix rectifier is determined by the AC input voltage U s , LC input filter, matrix converter, high-frequency transformer, post-stage uncontrolled diode, L-type filter, load R dc connected sequentially. The modulation method is to compare two positive and negative sinusoidal modulation waves with the same triangular carrier signal, modulate to generate four SPWM waves, and then perform coupling, that is, after "AND" logic synthesis with high-frequency square wave signals Vp and Vn Get eight driving waves, and then perform "or" logic synthesis to get four S ah , S al , S bh , S bl driving wave, that is, S nal and S pah Share a drive signal S ah , S nah and S pal Share a drive signal S al , S nbl and S pbh Share a drive signal S bh , S nbh and S pbl Share a drive signal S bl . The method can solve the problem that the primary voltage peak is generated because the primary current ip has no flow path due to the leakage inductance of the transformer. And it has less switching loss and better output voltage waveform quality.

The invention discloses a leakage inductance energy absorption and feedback circuit of a flyback transformer and a control method thereof. The leakage inductance energy absorption and feedback circuit is integrated together and formed by a clamper tube Sc and a clamper capacitor Cc only. The leakage inductance energy absorption and feedback circuit is simple and reliable in structure. According to the control method of the leakage inductance energy absorption and feedback circuit, the clamper tube is switched on for Tc after a flyback main tube is switched off, and Tc is half of a resonance period of leakage inductance and the clamper capacitor and far shorter than the switch-off time of the main tube. The leakage inductance energy absorbed by the clamper capacitor is released to a main power circuit by means of the resonance of the clamper capacitor and the leakage inductance, so that the switched-off voltage peak of the flyback circuit main tube is lowered effectively, and the efficiency of the flyback transformer is increased. Meanwhile, by means of non-complementary connection of the clamper tube and the main tube, the switch-on time of the clamper tube is far shorter than the switch-off time of the main tube, and therefore, the absorption and feedback circuit does not affect the switching process of the main tube and is suitable for flyback circuits in any operation modes. The circuit reliability and efficiency of a miniature photovoltaic grid-connected inverter utilizing the leakage inductance energy absorption and feedback circuit can be increased greatly.

The invention is concerned with zero-voltage-switching full bridge DC converter to clamp diode with current transformer. It belongs to DC converter and relates to DC power supply Vin, two invert bridge legs, resonant inductance, clamp circuit, transformer, rectifier and filtering circuit, current transformers, rectifier circuit of current transformers and DC power supply Vc. The clamp diode circuit eliminates voltage surge, pinnacle and the wastage arose by the inverted renew to the output rectifying tube, reduces the voltage stress of the output rectifying tube. The current transformer quickly reduces the current and improves the work condition of clamp diode.