58results about How to "Improve ripple" patented technology

The invention is intended to provide a control device for a vehicular AC motor, which has higher efficiency of voltage utilization in a power running mode and has higher efficiency of electricity generation in an electricity generation mode. The motor control device comprises rectifying devices and switching devices for three phases, which are connected between a DC power source and armature coils of an AC motor operatively coupled to an internal combustion engine. The motor control device has the inverter function of converting a DC power from the DC power source into an AC power and supplying the AC power to the armature coils, and the converter function of converting an AC power generated by the AC motor into a DC power and supplying the DC power to the DC power source. Rectangular-wave driving control of applying rectangular wave voltages to the armature coils of the AC motor is performed when the AC motor is operated for power running, and synchronous rectification control for making synchronous rectification of the AC power generated by the AC motor is performed when the AC motor is operated for electricity generation.

The invention relates to a system and method for determining direct current system fault branch circuits needing to be in in-series connection with alternating currents. The system comprises an on-line monitoring device, wherein the input of the on-line monitoring device is connected with the positive electrode and the negative electrode of a direct current bus and the ground; a plurality of fault locating devices are arranged in various direct current branch circuits respectively, and the on-line monitoring device is connected with each fault locating device through a communication bus. The method comprises the steps that 1) positive electrode voltage to ground U+, negative electrode voltage to ground U- and in-series connected alternating voltage Uac of the direct current bus are detected, and when the Uac is greater than a set value Uaca, the situation that a direct current system has alternating current in-series connection faults is determined; 2) when the U- is less than or equal to delta U, the situation that the alternating currents are connected to the direct current system in series through the positive electrode is determined; when the U+ is less than or equal to the delta U, the situation that the alternating currents are connected to the direct current system in series through the positive electrode is determined; 3) leak currents of all the branch circuits of the direct current system are detected and ordered, the branch circuit having the maximal leak current value is the branch circuit needing to be in in-series connection with the alternating currents. According to the system and method, an alternating current sensor does not need to be additionally arranged, and system cost is saved. Meanwhile, according to the scheme, signal injection does not exist, and therefore increase of ripples of the direct current system will not be caused, the problems that a relay mistakenly moves and a breaker mistakenly trips are solved, and reliability is higher.

In a power supply apparatus, a charge-pump type step-up circuit is adapted to charge a step-up capacitor by a power supply voltage, step up a charged voltage of the step-up capacitor using a charge-pump operation, and discharge a stepped-up voltage to a smoothing capacitor. A regulator has a first comparator adapted to compare a voltage corresponding to an output voltage of the step-up circuit with a reference voltage to generate a comparison output signal and skip a clock signal in accordance with the comparison output signal, so that the output voltage of the step-up circuit is brought close to a target voltage. Discharging of the smoothing capacitor is carried out through a resistor with a predetermined time constant when the output voltage of the step-up circuit is between the target voltage and a voltage lower than the target voltage by a predetermined value.

A two-switch Flyback power converter is disclosed. The two-switch Flyback power converter comprises a transformer, a first switch, a second switch, and a control circuit. The transformer includes a primary-winding and a secondary-winding. The primary-winding has a first winding and a second winding. The first switch is coupled to switch the first winding. The second switch is coupled to switch the first winding and the second winding. The control circuit generates a first-drive signal and a second-drive signal to control the first switch and the second switch for switching the transformer and regulating an output of the two-switch Flyback power converter. The two-switch Flyback power converter with less capacitance of the bulk capacitor or bulk capacitor-less can reduce the voltage ripples at the output voltage for cost saving.

The invention discloses a voltage-sharing and power-sharing control method of a single-phase multi-module cascading solid-state transformer. A power main circuit part of the single-phase solid-state transformer is composed of an AC / DC rectifying input stage, a DC / DC middle stage and a DC / AC output stage. The rectifying stage and the middle stage serve as a system for controlling and designing, a common duty ratio control strategy based on single-phase d-q vector control is adopted in the input stage, the output direct voltage of the middle stage serves as feedback quantity of an outer voltage loop, the stability of the output direct voltage of the middle stage is achieved, and a unity power factor of an input end of a power grid is achieved; a control strategy based on voltage feed-forward and voltage feed-backward is introduced into all modules in the middle stage at the same time, the voltage feed-forward serves the benchmark of the voltage feed-backward, and errors of the voltage feed-forward and voltage feed-backward serve as the benchmark of a module current inner loop after being output by a voltage PI regulator. The front stage control strategy is interacted with the middle stage control strategy, and therefore the purposes that voltage and the power of modules of an SST are balanced, the power grid side unity power factor is achieved, the power grid current sine degree is high, the voltage stress of a switch tube is low, and the ripple of the output direct voltage of the middle stage is low.

A high precision DC / DC resonant converter with a wide load range includes a first switch leg having one end connected to an anode terminal of a DC power source and the other connected to a cathode terminal of the DC power source to independently operate at a switching frequency used in an application of an output voltage for no load or a light load equal to or less than a rated load; and one or more second switch legs having one end connected to the anode terminal of the DC power source and the other end connected to the cathode terminal of the DC power source to operate at a switching frequency for the rated load or a frequency equal to or less than the switching frequency used in the application of the output voltage for no load or the light load that the first switch leg takes charge of.

A semiconductor device includes a boosting circuit that boosts an internal power supply voltage in a boosting range according to an external power supply voltage, an external voltage-level comparison circuit that compares the external power supply voltage and a predetermined reference voltage, and a variable resistor circuit that includes a variable resistor connected to an output terminal of the boosting circuit. The variable resistor circuit controls a resistance value of the variable resistor based on a comparison result of the external voltage-level comparison circuit.

The embodiment of the invention discloses a supporting plate and a folding display screen, the supporting plate comprises at least one bending area, at least one sliding and rolling area and non-bending areas, the bending area is used for bending, the sliding and rolling area is close to the edge of the supporting plate, and the sliding and rolling area is used for sliding and rolling. The non-bending areas are located on the two opposite sides of each bending area and located between the bending area and the sliding and rolling area. The bending area and the sliding and rolling area each comprise a plurality of first open holes arranged in an array mode. The supporting plate is designed to be of a structure with the bending area and the sliding and rolling area at the same time, and the first open holes in the array are formed in the bending area and the sliding and rolling area, so that the effect of supporting the flexible display panel can be achieved, the flatness of the flexible display panel is improved, and the supporting plate in the bending area has good extension performance and deformation recovery capability, so that the phenomena of corrugation and crease generated by the bending part of the flexible display panel in the prior art can be improved.

The invention relates to an intelligent scheduling high-efficiency power manager and a control method thereof. The intelligent scheduling high-efficiency power manager comprises a starting module, a switch capacitive type voltage stabilizer module and an LDO (low dropout regulator) module which are mutually connected; the starting module comprises a counter, a power-on reset circuit, a low-voltageoscillator, and a finite state machine; the finite state machine and the switch capacitive type voltage stabilizer module are connected with the LDO module; the switch capacitive type voltage stabilizer module comprises a clock control circuit, a voltage detection circuit, a mode switching circuit and a switch capacitive array circuit, the clock control circuit is connected with the mode switching circuit and the switch capacitive array circuit respectively, the voltage detection circuit is connected with the mode switching circuit and the switch capacitive array circuit respectively, the mode switching circuit is further connected with the switch capacitive array circuit; the mode switching circuit is further connected to the LDO module; and the LDO module is a master-slave structure LDO. The optimal working mode is automatically selected and switched to according to the input voltage, the efficiency of a power management chip is optimized, and the intelligent scheduling high-efficiency power manager is suitable for various applications with low power consumption.

Provided is a sheet conveying apparatus which can improve rippling of a sheet. The sheet conveying apparatus which conveys the sheet includes an electromagnetic hysteresis brake 131 which is configured to apply a tension force in a conveying direction of the sheet and a controller 500C which performs control on the electromagnetic hysteresis brake 131 to vary a load. The controller 500C performs control on the load of the electromagnetic hysteresis brake 131 according to information relating to the sheet.

The invention belongs to the field of analog integrated circuits, and specifically provides a frequency compensation scheme for an LDO regulator to drive large current loads. In the scheme, two-stage operational amplifiers having approximate monopole points, a buffer stage and an output stage. Capacitor compensation is introduced innovatively, so that a two-stage error amplifier originally having two low frequency pole points becomes an approximate monopole point system, and the position of the pole point can be manually controlled. According to the scheme, the pole point is set as a secondary pole point high in frequency, and after an output capacitance and parasitic resistor (ESR) is introduced in a parasitic zero point, the pole point is appropriately compensated. The output pole points changing with loads are still main pole points, and by reasonably selecting filtering capacitance of an output end, the generated zero point is located at the maximum loop gain GBW frequency. The inside parasitic zero point is located at high frequency due to the specific circuit structure. Finally, the whole low-pressure-difference linear voltage stabilizer achieves frequency stability in the full current load change range, and the phase margin is more than 50 degrees.

The invention belongs to the technical field of direct-current converters, particularly relates to a three-phase CLLC bidirectional direct-current converter and a control method thereof, and aims at solving the problems that the existing high voltage side series-low voltage side parallel structure based on modularization is large in number of modules, the reliability is poor, and the existing converter based on a multi-level technology is complex in circuit topology, uneven in capacitance voltage division and high in clamping tube voltage stress. The three-phase CLLC bidirectional direct-current converter comprises a high-voltage side voltage-dividing capacitor module, a three-phase half-bridge series / parallel module, a three-phase primary side / secondary side resonance module, a three-phase isolation transformer and a low-voltage side capacitor module, wherein the high-voltage side voltage-dividing capacitor module comprises three voltage-dividing capacitors; the three-phase half-bridge series / parallel module comprises three bridge arms which are connected in series / parallel, and each bridge arm comprises two switching tubes which are connected in series; the three-phase primary side / secondary side resonance module comprises an a-phase primary side / secondary side resonance cavity, a b-phase primary side / secondary side resonance cavity and a c-phase primary side / secondary side resonance cavity; and the three-phase isolation transformer comprises a single-phase transformer a, a single-phase transformer b and a single-phase transformer c. High-voltage side voltage division iscarried out through the voltage-dividing capacitor, the voltage stress of a clamping tube is reduced, the switching loss is reduced through the high-frequency soft switching technology, and the efficiency and the power density of the converter are improved.

The invention discloses an electric energy conversion device and a method for determining the optimal parallel connection number of direct-current circuits of the electric energy conversion device. The electric energy conversion device comprises a power supply module, N interleaving direct-current conversion circuits and an MPPT core control module, wherein the N interleaving direct-current conversion circuits are connected with the power supply module, and the MPPT core control module is connected with a control end of the N interleaving direct-current conversion circuits. The N interleaving direct-current conversion circuits comprise a voltage conversion circuit and an input filter capacitor, wherein the voltage conversion circuit serves as a voltage reduction unit or a boost unit or a boost / voltage reduction unit. The method for determining the optimal parallel connection number of the direct-current circuits of the electric energy conversion device comprises the steps that the range of the duty ratio of the direct-current conversion circuits is calculated, a graph of the relation between the duty ratio and electric current normalization ripple amplitudes is drawn, and finally the optimal parallel connection number is obtained according to the graph and the range of the duty ratio. According to the electric energy conversion device and the method for determining the optimal parallel connection number of the direct-current circuits of the electric energy conversion device, power supply reliability is improved, the maximum power output of a whole system is ensured, efficiency of the system is improved, the system can have the optimal output current ripple characteristic, the capacity of a filter is reduced, and the output power of the system is improved.

The invention discloses a TEC temperature control driving circuit which is characterized in that the circuit comprises a linear regulator LDO, a current absorbing circuit and a switching power supply SW circuit. The output end of the linear regulator LDO is connected with the LDO terminal of a TEC to provide input voltage V-LDO. The output end of the switching power supply SW circuit is connected with the SW end of the TEC to provide input voltage V-SW. According to the current absorbing circuit, when V-LDO is greater than V-SW, disconnection is carried out, and current flows from the linear regulator LDO into the TEC; when V-LDO is less than V-SW, breakover is carried out, and current flows from the TEC to the current absorbing circuit. According to the invention, a new LDO+SW topology circuit structure is designed, and the advantages of small LDO ripple and high SW efficiency are combined; the current absorbing circuit is added on the LDO terminal, so that the LDO terminal can output current and absorb current; and the same circuit is used to drive the TEC to carry out heating or refrigeration.

The invention discloses a wide-range voltage and high-current output method and a power system. Voltage and current are provided for a first MOS (metal oxide semiconductor) tube by a standard buck circuit; conduction impedance of the first MOS tube is adjusted according to a comparison result of an output feedback voltage VFB of the first MOS tube and a preset target voltage Vset, operation of thefirst MOS tube in a transverse flow area is realized, and accordingly wide-range voltage and high-current stable output of the power system is realized, and the problem of a narrow adjustable range of current non-isolated module output voltage is solved. In addition, the problem of high output voltage fluctuation under the condition of large-range dynamic changes of output current is solved, andripple and precision indexes of wide-range output power sources are optimized.

The invention provides a prestressed plastic corrugated pipe and a manufacturing method thereof. The prestressed plastic corrugated pipe comprises 30 parts to 50 parts of recycled regenerated plastic, 30 parts to 60 parts of recycled regenerated plastic, 30 parts to 50 parts of pure regenerated plastic, 2 parts to 8 parts of antiseptic agent, 1 part to 4 parts of antiaging agent, 1 part to 6 parts of adhesive and 0.1 part to 3 parts of pigment. The manufacturing method comprises the steps: adding formula materials into an extruding machine to carry out high-speed melting and kneading milling for 10 minutes to 30 minutes; extruding the formula materials into an extruding mould by the extruding machine; extruding, plasticizing and moulding the formula materials in a moulding machine at the temperature of 170 DEG C to 185 DEG C; reprocessing a circular degree by a reheating and moulding device; then, cooling and forming the formula materials by a cooling device; drawing tubing to increase the stretching stress; and finally, cutting as needed. The prestressed plastic corrugated pipe is mainly used for the departments of civicism, water conservancy, post, telecommunications, and the like, can be used as a drain pipeline and is arranged on the water transmission position of a highway overpass, a viaduct and a railway bridge.

The invention relates to the technical field of electronic circuits, in particular to a self adaptive voltage adjuster based on a PSM (pulse slope modulation) mode. The self adaptive voltage adjuster based on the PSM mode is used for self adaptive online adjustments of power voltage of a digital load. The self adaptive voltage adjuster based on the PSM mode uses a delay line to obtain a fitting critical path of the digital load, uses a work clock signal of the digital load as a delay test signal, uses a delay detection module to detect whether the transmission speed of the delay test signal in the delay line meets the requirement or not so as to obtain a self adaptive voltage adjustment signal, keeps conduction capacity constant by changing reference voltage of a power converter and the duty ratio of a PSM signal, and adjusts output voltage in self adaptive mode so as to achieve the purpose that work voltage of the load is minimum under given frequency. The self adaptive voltage adjuster based on the PSM mode has the effects that the PSM mode is adopted in the power converter, output voltage ripples are improved, the work voltage of the load is minimum, power dissipation of the load is effectively reduced, the area of a chip is saved, and integration is facilitated. According to the self adaptive voltage adjuster based on the PSM mode, the PSM mode is particularly suitable for various self adaptive voltage adjusters.

The invention discloses a film bulk acoustic resonator, which comprises a transfer substrate, a bonding layer, a filling layer, a bottom electrode, a piezoelectric film and a top electrode which are sequentially distributed from bottom to top, a sandwich structure is formed by the piezoelectric film, a bottom electrode and a first layer of the top electrode, and a groove is formed in the transfersubstrate, so that an air cavity is formed among the bottom electrode, the bonding layer and the transfer substrate; and bulk sound waves generated by the piezoelectric film can be totally reflected on the surface of the bottom electrode through the air cavity, so that the bulk sound waves are limited between the first layer of the top electrode and the bottom electrode, and the resonator functionis achieved. And meanwhile, the top electrode second layer and the top electrode third layer are arranged on the top electrode first layer and are respectively used for optimizing a series resonancepoint and a parallel resonance point of the thin film acoustic wave resonator, so that the parasitic effect is eliminated, and the quality factor is improved. The invention also discloses a preparation method of the film bulk acoustic resonator.

The invention is suitable for the technical field of a power supply, providing a filtering method for DC voltage output by a switching power supply and a filter device. The filter device comprises a switching control unit, a comparator and a sampling feedback unit, wherein the sampling feedback unit is used for sampling ripple voltage from the output end of the switching control unit and outputs the sampled ripple voltage to the comparator; the comparator is used for comparing the sampled ripple voltage with a set reference value and transmitting the comparison result to the switching control unit; the input end of the switching control unit inputs DC ripple voltage which is output by the switching power supply; and according to the comparison result, the DC ripple voltage which is output by the switching power supply, is controlled to be switched on and off.

The invention discloses a cover plate and a display device. The cover plate comprises a flexible layer and a transparent layer, at least one part of the transparent layer is arranged on the two sides of the flexible layer, and the rigidity of the transparent layer is larger than that of the flexible layer. The cover plate and the display device are used for solving the problem that ripples are generated when the cover plate is folded.

The invention discloses a double-Buck inverter improvement modulation method based on an auxiliary power supply. The method comprises the following steps of S1, designing a scheme: adopting two groupsof Buck circuits and adopting a time-sharing control mode; S2, adding the auxiliary power supply and an auxiliary switch, wherein S5 and S6 are auxiliary switches which are alternately conducted in positive and negative half periods, and Ub is the auxiliary power supply; S3, carrying out sine output calculation; and S4, carrying out working mode analysis, and dividing into a power frequency positive half period and a power frequency negative half period. By using the improvement modulation method of the invention, conduction losses of a switch tube can be effectively reduced, and a voltage stress and a current stress of the switch tube are obviously decreased; an inductive current fundamental wave, a ripple wave and an inductive voltage are all improved, and copper losses and iron lossesof a magnetic element are reduced; an electrolytic capacitor adopts the electrolytic capacitor with lower cost so that circuit cost and a volume can be effectively reduced; and in a modulation mode, differential output is performed through a group of Buck converters and the auxiliary power supply, accuracy is improved, and errors are reduced.

The embodiment of the invention provides an inductive device and an interleaved parallel direct current converter. The inductive device occupies a small volume and / or area of a substrate, thereby facilitating the miniaturization and low cost requirements of the inductive device. The inductive device comprises a first inductive unit and a second inductive unit, wherein the first inductive unit comprises a first conductive connection member and a first conductive layer, the first conductive connection member is connected with the first conductive layer, and first through holes are formed in the first conductive layer; the second inductive unit comprises a second conductive layer and a second conductive connection member, and the second conductive layer is connected with the second conductive connection member; and the second conductive connecting member is embedded and inserted into the first conductive connecting member through the first through holes to form a coaxial structure, and the projection of the first conductive layer of the first inductive unit and the projection of the second conductive layer of the second inductive unit on the first plane are at least partially overlapped.

The invention discloses an energy storage current transformer based on a multilevel DC / DC converter. The energy storage current transformer comprises three parts including application of the multilevel DC / DC converter, grid-connected mode control and off-grid mode control. The energy storage current transformer adopts a two-stage multi-DC / DC parallel topology. Each DC / DC module adopts a multileveldesign, and optimizes current ripples and harmonics. The inversion part adopts a three-phase voltage type PWM rectifier which has simple principle and is easy to implement. Through the study of functions of the energy storage current transformer under grid-connected / off-grid operating conditions, corresponding control strategies are formulated, and droop control and SOC feedback control are introduced into the control. The designed energy storage current transformer has excellent operating features while performing normal functions.