152results about "Conversion using Cuk convertors" patented technology

A system and a method provide a photovoltaic system which regenerates the output characteristics of the photovoltaic at different ambient condition with high precision under all environmental conditions. The photovoltaic system includes a photovoltaic array, a buck / boost converter, a DC link capacitor to connect the buck / booster converter to a load / inverter, an adaptive network-based fuzzy inference maximum power point tracking controller, a voltage control loop, a proportional integral controller to maintain the output voltage of the photovoltaic array to the reference voltage by adjusting the duty ratio of buck / boost converter.

A switching power converter tracks a time-varying input voltage during each cycle of the input voltage to provide power factor correction. The switching power converter includes a switch with a frequency and duty cycle modulated control signal. The switch controls the transfer of energy between the input and output of the switching power converter. The frequency of the control signal is greater than a frequency of the input signal. The control signal frequency is modulated during each cycle of the input voltage so that energy transferred from the switching power tracks the energy supplied to the switching power converter.

A DC-to-DC converter comprising an input inductor which is connected to an input terminal, an output inductor which is connected to an output terminal, a capacitor which is connected in series with and between the inductors, a switch element which is connected via a first resistor to a common input / output conductor and to a first node that is common to the input inductor and the capacitor, and a diode which is connected via a second resistor to the common input / output conductor and to a second node that is common to the output inductor and the capacitor, the switch element being responsive to a switch control signal (Vsw) applied thereto for alternately making the switch element conducting and non-conducting such that currents flowing through the inductors flow through the switch element or through the diode during an on-interval and an off-interval of the switch control signal (Vsw), respectively, a control circuit having at least one measurement input for receiving a current measurement voltage (Vx) across the first and second resistors, a reference input for receiving a reference signal (Vref), and an output for supplying the switch control signal (Vsw).

A DC to DC converter including a zigzag transformer. The transformer operates at high frequency with integrated magnetics and does not provide isolation. The multiphase converter has gate inputs with PWM signals appropriately phase-shifted depending on the number of phases to make balanced phase voltages across the transformer windings. The switching frequency of the converter is relatively low but fast transient response can be achieved by adding an integrated zigzag transformer.

A truly Bridgeless PFC converter is provided which eliminates the four-diode bridge rectifier and operates directly from the AC line to result in high-efficiency, small size and low cost solution for Power Factor Correction applications.

A new class of Three-Phase Isolated Rectifiers with Power Factor Correction provides a high efficiency, small size and low cost due to direct conversion from three-phase input voltage to output DC voltage.

The present invention employs a resonant inductor, a resonant capacitor and a hybrid transformer using a Hybrid-switching method with three switches which results in two distinct switched-networks: one for ON-time interval and another for OFF-time interval. Resonant inductor is placed in series with the hybrid transformer primary to insure the continuity of primary and secondary currents at the switching transitions. The hybrid transformer converts both inductive and capacitive energy storage from the source to the load. The two-phase extension results in tenfold reduction of the output current ripple.Despite the presence of the resonant inductor current during the OFF-time interval, the output voltage is neither dependent on resonant component values nor on the load current but depends on duty ratio D and turns ratio n of the hybrid transformer only. Thus a simple regulation of output voltage is achieved using duty ratio D control.

An inverter circuit having a primary circuit with a first choke for periodically connecting a primary winding to a DC voltage present at an input of the inverter circuit, a secondary circuit with a secondary winding, the secondary winding arranged in series with a first capacitor and connected via a full bridge consisting of four switching elements to a AC voltage present at an output of the inverter circuit via a second choke, and a transformer, wherein the primary circuit and the secondary circuit are electrically isolated by the transformer.

A solar power charging system comprising: a voltage converter for converting a voltage level of an original voltage generated by a solar battery into generate a charging voltage and for charging a capacitor by the charging voltage; and a duty ratio control circuit electrically coupled to the voltage converter for supplying a driving clock to the voltage converter for allowing the voltage converter to operate based on the driving clock, wherein the duty ratio control circuit adjusts a duty ratio of the driving clock based on a maximum charge power which depends on the original voltage generated by the solar battery.

A non-isolated power conversion system has an input stage and an output stage. A plurality of cascaded switching power converter stages are coupled between the input stage and the output stage. Each of the plurality of switching power converter stages has at least one switch that is activated in accordance with a duty cycle associated with a switching cycle. At least one energy storage device temporarily stores energy that is proportional to the duty cycle during the switching cycle for delivery to the output stage.

A power supply comprises a pair of first and second capacitors forming a capacitive voltage divider. A source of a periodic input supply voltage is coupled to the capacitive voltage divider for producing in the second capacitor, from a portion of the periodic input supply voltage, a second supply voltage that is coupled to a load circuit. A switch is coupled to the second capacitor for selectively coupling the first capacitor to the second capacitor in a manner to regulate the second supply voltage.

A SEPIC converter with over-voltage protection includes a high-side inductor that connects a node Vw to a node Vx. The node Vx is connected, in turn to ground by a power MOSFET. The node Vx is also connected to a node Vy by a first capacitor. The node Vy is connected to ground by a low-side inductor. A rectifier diode further connects the node Vy and a node Vout and an output capacitor is connected between the node Vout and ground. A PWM control circuit is connected to drive the power MOSFET. An over-voltage protection MOSFET connects an input supply to the PWM control circuit and the node Vw. A comparator monitors the voltage of the input supply. If that voltage exceeds a predetermined value Vref the comparator output causes the over-voltage protection MOSFET to disconnect the node Vw and the PWM control circuit from the input supply.

A DC to DC converter comprising a zigzag transformer is provided. The transformer operates at higher frequency with integrated magnetics and does not provide isolation. The multiphase converter has gate inputs with PWM signals appropriately phase-shifted depending on the number of phases to make balanced phase voltages across the transformer windings. The switching frequency of the converter is slightly lower but fast transient response can be achieved by adding an integrated zigzag transformer. The disclosed converter improves overall efficiency, reduces current ripple and simplifies current control.

The invention discloses a wide-range bidirectional conversion circuit and a control method. The wide-range bidirectional conversion circuit comprises a three-stage bidirectional converter and a control unit, and the three-stage bidirectional converter is formed by sequentially connecting a non-isolated DC / DC converter, an isolated DC / DC converter and a DC / AC inverter. When the system works in theforward direction, a direct-current power supply or energy storage equipment realizes grid-connected energy feedback through the non-isolated DC / DC converter, the isolated DC / DC converter and the DC / AC inverter; and during reverse working, an alternating voltage supplies power to a direct-current load or charges an energy storage device through a rectifying circuit, the isolated DC / DC converter and the non-isolated DC / DC converter. In order to adapt to different power levels and realize higher input current ripple control, the non-isolated converter adopts a multi-phase interleaved parallel structure; and in order to further broaden the requirements of input and output ranges in practical application, the isolated converter can be controlled by adopting a full-bridge / half-bridge variable structure. The whole system has the advantages of wide input direct-current voltage range, wide output alternating-current voltage range, wide load range, small current ripple, high-frequency isolation, high efficiency, energy conservation, environmental protection and the like.

A power supply includes a supply inductor and a first capacitor coupled to form a resonant circuit to generate a resonant waveform in a resonant operation, during a first portion of an operation cycle of the power supply. A charge storage element develops an output voltage to energize a load. A rectifier is coupled to the charge storage element and to the resonant circuit and is responsive to the resonant waveform for applying the output voltage back to the resonant circuit to interrupt the resonant operation, at an end time of the operation cycle first portion, when the resonant waveform produces a first change of state in the rectifier. A first sensor senses when the first change of state in the rectifier occurs. A source of a supply current is coupled to the rectifier and rectified in the rectifier to produce a rectified current that is coupled to the charge storage element to replenish a charge therein, during a second portion of the operation cycle. A switching transistor is responsive to an output signal of the first sensor for enabling the supply current to be coupled to the rectifier, during the operation cycle second portion, and for disabling the supply current from being coupled to the rectifier, during the operation cycle first portion.

An inverter circuit having a primary circuit with a first choke for periodically connecting a primary winding to a DC voltage present at an input of the inverter circuit, a secondary circuit with a secondary winding, the secondary winding arranged in series with a first capacitor and connected via a full bridge consisting of four switching elements to a AC voltage present at an output of the inverter circuit via a second choke, and a transformer, wherein the primary circuit and the secondary circuit are electrically isolated by the transformer.

Disclosed is a low noise, non-isolated DC-DC converter for providing a non-inverted (i.e., the same polarity as an input voltage) output voltage of any desired voltage by stepping-up / down the input voltage. It comprises an input coil L1, an input capacitor C1 and a second intermediate coil Lm2 connected in series between both ends of the input voltage source, an output coil L2, an output capacitor C2 and a first intermediate coil Lm1 connected in series between both ends of a load Ro, a switching device S connected between a node a of the L1 and the C1 and a node b of the C2 and the Lm1, and a diode D connected between a node d of the C1 and the Lm2 and a node c of the C2 and the L2.

A method and an apparatus for transferring electric power to an electrical load (105); the method comprising steps of: converting a direct electric current into an electric tension wave, applying the electric tension wave in inlet to at least a couple of electric capacitors (125, 130); supplying the electrical load (105) with the electric tension in outlet from the capacitors (125, 130).

Disclosed is a protection cover allowing a handheld device to reversely discharge, which includes a bidirectional DC-DC converter and a charging / discharging controller arranged inside the protection cover so as to allow a first handheld device that is received in the protection cover to externally discharge electrical power thereof. The protection cover applies a removable external connection to electrically connect to a second handheld device so as to allow the first handheld device to reversely discharge, via the protection cover, to the second handheld device.

The invention provides a device and method of inhibiting potential induced degeneration (PID). The device is connected between the alternating current output terminal of a current transformer and a grid connected power frequency transformer, and comprises a rectification module, a non-isolated level conversion module and at least one capacitor. The input terminal of the rectification module is in connection with the output terminal of the current transformer; the rectification module rectifies the alternating current outputted by the current transformer into direct current; the non-isolated level conversion module performs level conversion on the direct current outputted by the rectification module; level conversion is boost conversion or voltage reverse conversion; or, the input terminal of the non-isolated level conversion module is in connection with the output terminal of the current transformer; the non-isolated level conversion module is used for performing level conversion on the alternating current outputted by the current transformer, and level converted is boost conversion; the rectification module rectifies the alternating current outputted by the non-isolated level conversion module into direct current; a capacitor is in parallel connection with the output terminal of direct current, and the anode or cathode of the capacitor is grounding. The device can avoid or decrease photovoltaic cell panel PID effects.

The present invention provides a power supply arrangement with a DC-to-DC converter (10) for providing at least one supply voltage to a load (20, 30, 40) from an energy source (11). The converter comprises means for inputting (4) a battery voltage from the energy source to output a voltage in a predetermined battery voltage range and a transfer circuit (8) connected to said means for inputting, to convert the battery voltage to at least one supply voltage in such a way that the supply voltage will be opposite in polarity to the battery voltage and the absolute value of the supply voltage will be the same or close to the absolute value of the battery voltage. The arrangement also comprises means for controlling (2), connected to the means for inputting, to control the supply voltage independent from the battery voltage using a single converting mode for the supply voltage range. The advantage of the arrangement is to supply continuously and ripple-free to the load the supply voltage range independent from but opposite in polarity to the battery voltage.

An electrical circuit for providing electrical power for use in powering electronic devices is described herein. The electrical circuit includes a power converter circuit that is electrically coupled to an electrical power source for receiving alternating current (AC) input power from the electrical source and delivering direct current (DC) output power to an electronic device. The power converter circuit includes a transformer and a switching device coupled to a primary side of the transformer for delivering power from the electrical power source to a primary side of the transformer. A controller is coupled to a voltage sensor and the switching device for receiving the sensed voltage level from the voltage sensor and transmitting a control signal to the switching device to adjust the voltage level of power being delivered to the electronic device.

The invention discloses an inverter for restraining the leakage current, wherein the inverter comprises a multi-level inverter bridge arm, a DC-DC converter, a first capacitor and a second capacitor.The positive input end and the negative input end of the DC-DC converter are respectively connected with the positive end and the negative end of a DC power supply. The positive input end and the negative input end of the inverter bridge arm are connected with the positive output end and the negative output end of the DC-DC converter respectively. The output end of the multi-level inverter bridgearm is connected with an AC power grid. The first capacitor and the second capacitor are connected in series and then are connected between the positive input end and the negative input end of the multi-level inverter bridge arm. The middle point of the multi-level inverter bridge arm is connected with a common point between the first capacitor and the second capacitor. The middle point of the multi-level inverter bridge arm is connected with the positive end or the negative end of the DC power supply. The N line of the AC power grid is connected with the middle point of the multi-level inverter bridge arm. Namely, the inverter for restraining the leakage current and provided by the invention is used for directly grounding the positive end or the negative end of the DC power supply. Therefore, the leakage current of the inverter is approximately zero.

The disclosure describes a charge device capable of charging electricity storage cells while eliminating a voltage variation among the electricity storage cells without a need for at least a circuit section playing a role in voltage equalization among the electricity storage cells to be designed to have a large current capacity, and describes a charge-discharge device constructed by additionally equipping a discharging function with the charge device. Provided are a charge device and a charge-discharge device each of which comprises a convertor, an input circuit, and a multi-stage voltage doubler rectifier circuit. An element in the convertor configured to be applied with a rectangular waveform voltage is connected to the multi-stage voltage doubler rectifier circuit via the input circuit to thereby realize a voltage equalization function, and an output section of the convertor is connected to the multi-stage voltage doubler rectifier circuit to thereby realize a charging-discharging function.

A DC-DC converter includes a power conversion portion including a switching element; a first resistor having one terminal electrically connected to the power conversion portion; a second resistor having one terminal electrically connected to the other terminal of the first resistor; a third resistor having one terminal electrically connected to the other terminal of the first resistor; a constant current supply electrically connected to the other terminal of the third resistor; and a control circuit electrically connected to the other terminal of the third resistor and configured to control the switching element. Resistance R1 of the first resistor, resistance R2 of the second resistor, resistance R3 of the third resistor, a reference current Iref output from the constant current supply, and an output voltage Vout output from the power conversion portion satisfy a following formula:{(1+R3R2)·R1+R3}·Iref>-Vout.

The present invention addresses the problem of providing a charger which is capable of performing charging while eliminating variations in the voltages of storage cells and which does not require that at least the circuit part responsible for equalization of the voltages of the storage cells be designed to have a large current capacity, the present invention also addressing the problem of providing a charger-discharger further equipped with a discharging function in such a charger. Provided are a charger and a charger-discharger, comprising a convertor, an input circuit, and a multi-stage voltage doubler rectifier circuit. A voltage equalization function is implemented by connecting an element in the convertor to which a rectangular wave voltage is applied to the multi-stage voltage doubler rectifier circuit via an input circuit, and a charging-discharging function is implemented by connecting the output of the convertor to the multi-stage voltage doubler rectifier circuit.

An integrated-type high step-up ratio DC-AC conversion circuit with an auxiliary step-up circuit applies to converting a low DC voltage of alternative energy into a high AC voltage. The conversion circuit uses an isolated Cuk integration unit and an auxiliary step-up unit to form a multi-phase input and uses parallel charging and cascade discharging to boost the DC voltage in the DC side with a low voltage power switches and low duty cycle and then converts the boosted DC voltage into AC voltage. The auxiliary step-up unit not only shares the entirety of power but also exempts the DC-side circuit from using high voltage power switches, whereby the cost of elements is reduced. Further, the conversion circuit can decrease the switching loss and conduction loss of the DC-side switches and promote the efficiency of the circuit.

A power supply comprises a pair of first and second capacitors forming a capacitive voltage divider. A source of a periodic input supply voltage is coupled to the capacitive voltage divider for producing in the second capacitor, from a portion of the periodic input supply voltage, a second supply voltage that is coupled to a load circuit. A switch is coupled to the second capacitor for selectively coupling the first capacitor to the second capacitor in a manner to regulate the second supply voltage.