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

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 for supplying power for the modules.

The invention relates to a bridge-type soft shutdown circuit, the input terminal is connected to an external shutdown control signal, and the output terminal is connected to the error signal terminal of the external control chip, including: a triode, the emitter of which is electrically connected to the error signal of the control chip terminal, the collector is grounded; a charging and discharging circuit, which outputs a high voltage to the base of the transistor during normal operation and outputs a low voltage to the base of the transistor according to the external shutdown control signal. The circuit cooperates with the full-bridge synchronous rectification main circuit and the secondary side drive circuit, which eliminates the voltage spike on the synchronous rectifier tube on the secondary side of the full-bridge synchronous rectification main circuit during shutdown, and enhances the reliability of the system.

The DC convertor is composed of DC power supply, first inversion bridge arm, second bridge arm, resonant inductance, isolating transformer, rectifying and filtering circuit, current transformer, and clipper circuit. The added current transformer and clipper circuit eliminates voltage surge and voltage pike caused by backward recovery of rectifying tube, reduces voltage stress of rectifying tube, and eliminates waste caused by backward recovery of rectifying tube. Since voltage stress of clamp diode is smaller, tube with good capability can be selected to eliminate influence on circuit caused by stray parameter of clamp diode. Moreover, Comparing with mode that a clamp diode is placed at primary side of transformer to clip voltage at primary side, the clipper circuit clips voltage at secondary side of transformer in the invention can eliminate voltage surge and voltage pike of rectifier diode caused by leakage inductance of transformer.

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 in parallel; 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 invention discloses a parallel resonant zero voltage switch push-pull forward converter. The main circuit of the converter comprises a primary circuit and a secondary circuit. The primary circuit is internally provided with a resonant inductor and a parallel resonant capacitor. Through the resonance of the resonant inductor and the parallel resonant capacitor, the zero voltage switching of a main power tube in the primary circuit is realized. According to the converter, the voltage spike of the main power tube can be reduced, an EMC effect is improved, and the voltage boost ability and conversion efficiency are improved. The parallel resonant zero voltage switch push-pull forward converter has the advantages of a simple circuit structure, convenient control and reliable working.

The invention provides a single battery being capable of resisting overloading and high-spinning and being high in capacity. A preparation method includes the steps of: successively tightly laminatinga nickel square-mesh net, a graphite sheet, positive powder, insulation powder, a negative pole sheet and a current collector; surrounding and compacting the outer rings of the insulation powder andthe negative pole sheet by a current blocking ring which is produced by mixing and pulping MgO and asbestos according to mass ratio of 2:1 and punching the mixture into a ring; the insulation powder is a mixture of LiCl-LiBr-LiF ternary eutectic substance and MgO according to the mass ratio of 1:1-1:1.5, wherein the mixture is compressed to form an insulation layer being 0.4-0.6 mm in thickness; the positive powder is a CoS2 / FeS2 mixture according to the mass ratio of 1:1, wherein the positive powder also contains insulation powder accounting for 15-18% by mass of the positive powder and lithium oxide accounting for 2-5% by mass of the positive powder. The single battery has strong anti-severe environment capability, can output stable voltage and is high in specific energy, and also satisfies the demand of resisting overloading and high-spinning and being long in service life.

A leakage inductance energy absorption circuit for Flyback converters, which is disclosed by the invention, can effectively absorb the energy accumulated in parasitic inducers and clamp switching voltage, consequently, surge current can be inhibited, the effect of eliminating the voltage peak of a main switch can be effectively realized, the efficiency of a system can be greatly increased as well while the temperature rise of the main switch can be decreased, and moreover, a stable output voltage can be obtained by means of the leakage inductance energy absorption circuit. The invention as the leakage inductance energy absorption circuit for Flyback converters can be widely applied in power supply products.

The invention discloses a flyback converter leakage inductor absorption and feedback circuit, and belongs to the technical field of an integrated circuit. The circuit combines leakage inductor energy absorption and a feedback circuit together, is composed of a clamping capacitor C1 and a clamping switch tube S2, and is simple and reliable in structure and convenient to control. Compared to a conventional RCD absorption mode, the capacitor C1 only functions to absorb leakage inductor energy and release the leakage inductor energy to a main circuit when the switch tube is conducted, realizes absorption and feedback of the leakage inductor energy and effectively improves the efficiency of a flyback converter. At the same time, since the conduction time sequence of the switch tube S2 and the conduction time sequence of a switch tube S1 are the same, the requirements for the time sequence driving design of the S2 are greatly simplified, and such a control mode is also applied to flyback transformation circuits of any modes. The circuit structure provided by the invention has an advantage in a small-power flyback converter.

The invention discloses a two-level cascaded multilevel inverter which is formed by the series connection of a front level unit and a back level unit. The front level unit is formed by n switch-diode units and a peak elimination switch, wherein the DC power supply negative end of an ith switch-diode unit is connected to the connection point of the switch and diode in an (i+1)th switch-diode unit, the peak elimination switch is connected across the connection point of the switch and diode in a second switch-diode unit and the negative end of the DC power supply of an nth switch-diode unit, a back level unit input side end point A is introduced from the connection point of the switch and diode in a first switch-diode unit, an end point B of the back level unit is introduced from the DC power supply negative end of a last switch-diode unit, and the back level unit is an H bridge inverter circuit. According to the two-level cascaded multilevel inverter, the voltage peak problem of a traditional cascaded switch-diode inverter output voltage base is solved, and the two-level cascaded multilevel inverter has the advantages of low cost and high reliability.

The invention discloses an active clamping LED driving power supply without an electrolytic capacitor. The active clamping LED driving power supply comprises an AC input power supply, an input filtering part, a rectification part, a clamping circuit, a flyback converter, an output filtering capacitor Co, a parallel absorption loop and an LED load. The input filtering part is composed of an input filtering inductor and an input filtering capacitor. The rectification part is composed of four switch tubes. The clamping circuit is composed of a switching tube S2 and a clamping capacitor Caux; theflyback converter is composed of a flyback transformer, a switching tube S1 and a diode Ds. The flyback transformer comprises a primary side winding and a secondary side winding, the primary side winding comprises a main inductor Lm and a leakage inductor Lr, the primary side winding is connected with the input, and the secondary side winding is connected with the output; the parallel absorption circuit comprises a boost inductor Lb, a switching tube S3, a switching tube S4 and an energy storage capacitor Cds. According to the invention, the active clamping circuit is introduced, so that the switching stress of the switching tube S1 is reduced; both the switching tube S1 and the switching tube S2 realize soft switching, so that the switching loss is reduced; meanwhile, leakage inductance energy can be fed back.

The present invention relates to an accelerator power supply apparatus of electron beam microfabrication equipment and a control method thereof. The apparatus includes an incoming line filter, a low-voltage rectifier bridge, an invert unit, a high-voltage unit and a regulator. The input end of the incoming line filter connects an external power grid. The output end of the incoming line filter, the low-voltage rectifier bridge, the invert unit and the input end of the high-voltage unit are connected in series orderly. The high-voltage output end of the high-voltage unit outputs high voltage, a high-voltage feedback signal U outputted by the signal end of the high-voltage unit is transmitted to the second input end of the regulator, the first input end of the regulator inputs a high-voltage setting signal U*, and the output end of the regulator connects the signal end of the invert unit. Compared to the prior art, the acceleration power supply apparatus of electron beam microfabrication equipment and the control method thereof solve a problem that the output end of an accelerator power supply occurs a spike voltage caused by a PWM converter working in a discontinuous current mode.

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 discloses a full-bridge converter with a freewheeling path. The full-bridge converter comprises a full-bridge bridge arm 1, a DC blocking capacitor 2, an energy transfer transformer 3, an energy main output path 4 and an energy freewheeling path 5. The full-bridge bridge arm is composed of four power switching devices. The DC blocking capacitor 2 and the primary winding of the energytransfer transformer 3 are connected in series and connected with the center of the leading arm and the lagging arm of the full-bridge bridge arm respectively. The energy main output path 4 is composed of a main secondary winding of the transformer 3, four rectifier diodes and a main filtering inductor. The energy freewheeling path 5 is composed of an auxiliary secondary winding of the transformer 3, four rectifier diodes, a pi-type filter, a resonant capacitor and a freewheeling clamping diode. The energy main output path 4 and the energy freewheeling path 5 are connected in parallel. According to the full-bridge converter with freewheeling path, the defects of large voltage stress, loss of duty ratio, large circulation loss and the like of a rectifier diode existing in a traditional full-bridge converter are overcome; and the wide range of the output voltage from zero to the maximum gain can be realized.

The invention discloses a switch control circuit, which comprises a PNP (Positive Negative Positive) type triode, an insulated gate field effect tube, a first diode, a second diode, a first resistor, a second resistor, a third resistor and a first capacitor, wherein the base of the PNP type triode is connected with the anode of the first diode; the emitter of the PNP type triode is connected with the cathode of the first diode; the gate of the insulated gate filed effect tube is connected with the cathode of the first diode; and the drain of the insulated gate filed effect tube is connected with the anode of the second diode. The starting speed of the switch control circuit is lowered through the first resistor and the first diode tube, and the shut-down speed of the switch control circuit is increased by using the PNP type triode.

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 a switching method applied to a charging module transformer winding switching device. A high-frequency transformer, a switching tube, a controller, a driving circuit and a high-frequency inverter circuit are included. Three taps are arranged on the secondary side of the high-high frequency transformer, two taps are connected with switching tubes which are connected in series reversely, and the controller controls the high-frequency inverter circuit and the switching tubes through a driving circuit; and the controller adjusts the control quantity of the high-frequency inverter circuit according to the winding switching proportion, executes a four-step current conversion method at the same time, and controls the switch-on or switch-off of the switching tube, and the winding is switched from high voltage to low voltage or from low voltage to high voltage. According to the invention, flexible seamless switching between windings is realized, peak voltage is eliminated, and the service life of a switching tube is prolonged; the controller judges the directions of the secondary winding currents is1 and is2 according to the control quantity of the high-frequency inverter circuit, the current direction does not need to be judged through a detection circuit, and the circuit structure is simplified; the converter realizes continuous high-power output in different output stages, and the efficiency of the converter is improved.

The invention provides a protection circuit and a battery management system with the same. One end of the protection circuit is electrically connected to a power supply module, the other end of the protection circuit is electrically connected to a battery, and the protection circuit at least comprises a primary filtering unit, a first voltage dividing unit and a secondary filtering unit which are electrically connected in sequence. The protection circuit provided by the invention is better in surge impact prevention effect and higher in stability, and meets protection requirements.

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.

The invention provides a preparation method of a wet process and dry process thermal battery composite positive electrode. The advantages of a wet process FeS2 positive electrode and a dry process CoS2 positive electrode are absorbed, the self capacity is improved, the test is carried out under the same electrical property condition, the wet process and dry process positive electrode has no voltage peak at the initial discharge stage, the working time can be prolonged by 10-30%, and meanwhile, the composite positive electrode is suitable for the discharge of a high-power thermal battery.

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.

The invention belongs to the field of direct-current converters, particularly relates to an isolated direct-current boost converter of a two-phase parallel boost circuit and a control method of the isolated direct-current boost converter, and aims to solve the problem that an existing isolated direct-current converter cannot adapt to a wide voltage range and high gain and cannot realize high-efficiency conversion in a whole load range. According to the invention, a two-phase input inductor and two bridge arms of a full-bridge unit form a two-phase parallel Boost circuit for boosting and stabilizing an input DC voltage; the DC bus capacitor carries out voltage filtering after voltage boosting and voltage stabilization; the series resonance circuit resonates and realizes power transmission from the primary side to the secondary side through the high-frequency transformer; and the output rectifying and filtering circuit performs high-frequency rectifying and filtering on the output voltage of the high-frequency transformer to obtain output direct-current voltage. The high-frequency series resonance with the leakage inductance is introduced to eliminate the voltage peak caused by the leakage inductance, the high-frequency resonance is combined with the PWM modulation to realize the soft switching of the switching tube in a wide voltage range, and the loss is reduced while the gain and the efficiency are improved.

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 ZCS-PWM Superbuck converter with low electrical stress, comprising a main switch circuit and an auxiliary circuit, the main switch circuit includes a main switch tube and a diode anti-parallel with the main switch tube, the auxiliary circuit includes an auxiliary switch tube, and the auxiliary switch An auxiliary diode is connected between the emitter of the tube and the emitter of the main switching tube, and a resonant branch is connected to the emitter of the auxiliary switching tube. A clamping diode is connected, an energy storage capacitor is connected between the anode of the clamping diode and the collector of the auxiliary switching tube, and a freewheeling current is connected between the emitter of the main switching tube and the connection node of the resonant capacitor and the resonant inductance in the resonant branch. diode. The converter combines the soft switching technology and the Suerbuck converter, so that it has the advantages of low electrical stress, small volume and weight, high efficiency, long life, and little pollution to the power grid.

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 provides a multi-level SiC-MOSFET driving circuit and a control method, including a SiC-MOSFET, a first-level driving circuit for providing a driving current to turn on the SiC-MOSFET, and a voltage dynamic waveform for collecting the voltage dynamic waveform during the turning-on process of the SIC-MOSFET The detection circuit, the secondary driving circuit for supplementing the driving current, and the control circuit for the secondary driving circuit; the control circuit comprises a waveform shaping module, a counting module and a control module which are sequentially signal-connected; the control circuit comprises waveforms which are sequentially signal-connected Shaping module, counting module and control module. The invention realizes the rapid turn-on of the SiC-MOSFET through the two-stage driving circuit, eliminates the voltage peak when turning on, and reduces the voltage oscillation when turning off; and obtains the voltage dynamic parameters during the turning-on process, and then adjusts the secondary driving circuit through the control module to supplement the The size of the drive current to provide a stable drive voltage.

The invention relates to a control method of a direct alternating current-alternating current conversion circuit and a power regulation method, the control method is applied to the direct alternating current-alternating current conversion circuit, and the direct alternating current-alternating current conversion circuit is controlled to work in a working mode by receiving an input alternating current voltage signal according to the input alternating current voltage signal. Switching state information is obtained, the target half-bridge unit and the continuous duration of the working state of the target half-bridge unit are determined according to the switching state information, and finally the target half-bridge unit is controlled to maintain the continuous duration of the working state so as to control the conversion circuit to switch from one working mode to another working mode. The load connected with the conversion circuit is provided with the follow current path, so that the voltage spike can be eliminated only by continuing the working state of at least one of the first half-bridge unit and the second half-bridge unit in the conversion circuit for a period of time, additional elements do not need to be added in the direct alternating current-alternating current conversion circuit, the element cost is reduced, and the control method is easy to implement.