59 results about "Ripple cancellation" patented technology

Systems, methods and devices for power generation systems are described. In particular, embodiments of the invention relate to the architecture of power conditioning systems for use with fuel cells and methods used therein. More particularly, embodiments of the present invention relate to methods and systems usable to reduce ripple currents in fuel cells.

an amount of charge transferred by a power converter is estimated by developing a signal that is a combination of signals representing an output voltage of a power converter and an inductor current of the power converter, charging a capacitor with a current proportional to that signal and comparing a voltage developed across the capacitor due to that charging to develop a signal for initiating a pulse to control input of power from a voltage source to the power converter. By using a signal developed in this way, response to both step-up and step-down transients can be improved and, in multi-phase embodiments, ripple cancellation problems such as noise susceptibility and loss of pulse generation can be entirely avoided.

Hydraulic pumps / motors are used to convert between rotational motion / power and fluid motion / power. Pressure differential is achieved across the pump / motor by applying torque to either aid or impede rotation which generally results in either a pressure rise or pressure drop respectively across the unit. This torque is often supplied by an electric motor / generator. Especially in positive displacement pumps / motors this pressure differential is not a smooth value but rather it contains high frequency fluctuations known as pressure ripple that are largely undesirable. With thorough analysis it can be discovered that these fluctuations occur in a predictable manner with respect to the position (angular or linear) of the pump / motor. Using a model that contains this information, a feed-forward method of high-frequency motor torque control is implemented directly on the hydraulic pump / motor by adding to the nominal torque, a model-based torque signal that is linked to rotor position. This high-frequency signal acts directly on the hydraulic pump / motor to reduce or cancel the pressure / flow ripple of the pump / motor itself without the need for any secondary flow generating devices.

The invention discloses a ripple elimination loop for a capacitance coupled chopper amplifier. An output voltage ripple of a chopper amplifier is converted to an AC signal, the AC signal is modulated to a DC signal, the DC signal is integrated by an integral module to obtain an integral voltage, and the integral voltage is converted to a compensating current through a transconductance module to compensate the offset voltage of the chopper amplifier and suppress the output voltage ripple of the chopper amplifier. In addition, according to the ripple elimination loop disclosed by the invention, the offset voltage of the integral module can be greatly suppressed by using the combination of a high-frequency chopping technology and a Ping-Pong self-zeroing technology in the ripple elimination loop, and thus the accurate integral voltage can be obtained, the accurate compensating current can be formed to suppress the offset current of a main amplifier in the chopper amplifier, and a good effect of suppressing the output voltage ripple of the chopper amplifier can be achieved.

A power converter includes an isolated or a nonisolated current-doubler rectification circuit including two magnetic circuit elements, each magnetic circuit element formed with a primary winding and a voltage-sensing winding. The primary windings are coupled in series. The voltage-sensing windings are also coupled in series but with a coupling sense opposite from that of the primary windings. A properly sized inductor and capacitor are coupled in series with the voltage-sensing windings to produce a ripple-cancellation current with slope opposite to a net slope error of currents produced in the two magnetic circuit elements. The current-doubler rectification circuit is preferably coupled to a rectangular ac input waveform. By sensing a scaled voltage difference between two magnetic circuit elements, a very low level of output ripple is produced by the circuit with very low power losses over a range of operating conditions.

An inverter device has an active ripple cancellation boost circuit being configured to a DC source from a plurality of solar cells and configured to filter an AC current ripple back to the DC source and boost the DC voltage to an intermediary 12-15 voltage range. The device has a wave shaper circuit comprising a phase shift zero voltage switching full bridge circuit and a rectifier energy recovery circuit, the phase shift zero voltage switching full bridge circuit configured to shape the DC source to a half wave rectified 120V to 240V waveform. The device has an analog mixed signal controller module configured to generate a PWM waveform and synchronize the rectified waveform to a grid voltage.

A low-ripple power supply includes a storage capacitor coupled across load terminals, and an inductor connected to a source of voltage including a varying or pulsatory component and a direct component, for causing a flow of current to said capacitor through the inductor. The varying component of the inductor current flowing in the capacitor results in ripple across the load. A winding is coupled to the inductor for generating a surrogate of the varying inductor current. The surrogate current is added to the inductor current to cancel or reduce the magnitude of the varying current component. This cancellation effectively reduces the varying current component flowing in the storage capacitor, which in turn reduces the ripple appearing across the load terminals.(121)

Systems, methods and devices for power generation systems are described. In particular, embodiments of the invention relate to the architecture of power conditioning systems for use with fuel cells and methods used therein. More particularly, embodiments of the present invention relate to methods and systems usable to reduce ripple currents in fuel cells.

An AC-DC power supply circuit utilizing an output stage configuration designed to achieve no output ripple at the power line frequency. To eliminate the ripple formed, each separate processing output stage corresponding to a respective ac voltage source phase which provides a 120 Hz ripple, is stacked, in a series connection, and due to their respective ripple phase shifts of 120° degrees, achieves ripple cancellation at the output.

The present invention provides a three-port converter with magnetic integration and current ripple cancellation. With magnetic integration technology, the number of magnetic rings is reduced, and the number of driving coupling transformers is also reduced, thereby greatly reducing the size and weight of the whole converter; and with a current ripple cancellation branch, the amount of current ripples flowing through the three ports is very low and close to zero. The three-port converter of the present invention reduces the influence of electromagnetic interference and simultaneously saves the filter cost so that the busbar current and battery current are smoother.

The invention relates to the technical field of power supply chips, and discloses an RBCOT-BUCK circuit for improving transient response and high stability. The RBCOT-BUCK circuit comprises an RBCOT internal loop and an RBCOT external output circuit, and further comprises a ripple cancellation circuit, wherein the ripple cancellation circuit is arranged in the RBCOT internal loop and used for generating a compensation ripple signal with the amplitude being identical or close to that of an output feedback voltage ripple signal of the RBCOT and the phase being opposite to that of the output feedback voltage ripple signal of the RBCOT, and an output signal of the ripple cancellation circuit is superimposed with the output feedback voltage ripple signal of the RBCOT and then connected to the RBCOT internal loop. According to the technical scheme of the invention, the compensation ripple signal is generated in the RBCOT internal loop, and the stability of the RBCOT loop is greatly improvedthrough cancelling the feedback voltage ripple; and meanwhile, the load transient response performance of the RBCOT structure is enhanced, and the mutual restriction between the transient response performance of the RBCOT and the stability of the loop is effectively eliminated. The load transient performance of the circuit is can be pushed to the limit, the design difficulty is greatly reduced, and the performance of the RBCOT structure is improved.

Methods of extending runtime with battery ripple cancellation in a CPU based system by providing a CPU that includes an input pin capable of throttling the power consumed by the CPU responsive to the input of a throttling signal, sensing a ripple in the form of a decrease in voltage or an increase in current responsive to a load on a CPU power supply, and when the ripple exceeds a predetermined limit, providing a throttling signal to the input pin to throttle the CPU to reduce the ripple.

A multi-module DC-DC converter provides synchronization between modules based on identification of a module within a chain. A resistor network can be used for the chain so that each module obtains a particular voltage based on its position within the chain. A master module provides a source current to drive the chain so that each module can determine its relative position in the chain based on voltage readings. With this configuration, a master module can determine how many modules are in the chain, and each slave module can determine its relative position in the chain. The module information contributes to synchronization between the modules for use in current ripple cancellation, for example, in the multi-module DC-DC converter.

The invention discloses a symmetric rectifying circuit capable of counteracting output current ripples, which comprises a power transformer with four secondary side windings, two flying and balancing capacitors and two rectifier diodes. The symmetric rectifying circuit can effectively counteract the output current ripples by using the symmetric secondary side windings of the transformer and the flying and balancing capacitors without any additional active auxiliary element, so as to greatly reduce the capacitance value and volume of an output filter capacitor; and the symmetric rectifying circuit suppresses the voltage parasitic oscillation on a secondary side rectifying tube output junction capacitor, clamps the voltage stress of a rectifying tube at double output voltage, reduces the level of the withstand voltage of the rectifying tube and reduces the on-state loss of the rectifying tube. In addition, the effective reduction of the current in the secondary side windings of the transformer reduces the loss of the secondary side windings. Therefore, the symmetric rectifying circuit can effectively improve the overall conversion efficiency and the power density of the transformer while taking production cost into consideration.

Provided are circuits and methods for use with a power supply that provides a main output including a main DC voltage having a first AC voltage ripple, or a main DC current having a first AC current ripple. A ripple cancellation converter provides a second AC voltage ripple connected in series with the main output, such that the first AC voltage ripple is substantially cancelled; or a second AC current ripple connected in parallel with the main output, such that the first AC current ripple is substantially cancelled. As a result, substantially ripple-free DC output power is provided.

Described herein are methods and circuits for improving the performance of an AC to DC power supply. The methods and circuits achieve high power factor (PF) at the AC side and at the same time, reduce or substantially eliminate ripple in the DC output power. The methods and circuits provide an isolated topology including primary side voltage and current sensing and primary side ripple cancellation control. The methods and circuits may be used in any application where high power factor and / or low output ripple are required. In particular, the methods and circuits may be used in DC lighting applications, such as in light emitting diode (LED) lighting, wherein suppression of low frequency ripple in the output power eliminates visible flickering.

The invention discloses a ripple suppression circuit of output current. The ripple suppression circuit of the output current comprises an inductive circuit, a ripple cancellation circuit and a blocking circuit, wherein a primary-side dotted terminal of the inductive circuit is connected to an input end of an output filter inductor of a DC-DC switching power supply circuit as the input end; a secondary-side dotted terminal of the inductive circuit is connected to an output end of the blocking circuit as the input end; a primary-side non-dotted terminal of the inductive circuit is connected to the output end of the output filter inductor of the DC-DC switching power supply circuit as the output end; a secondary-side non-dotted terminal of the inductive circuit is connected to the input end of the ripple cancellation circuit as the output end; the input end of the blocking circuit is connected to a cathode of the DC-DC switching power supply circuit; and the output end of the ripple cancellation circuit is connected to an anode of the DC-DC switching power supply circuit. According to the ripple suppression circuit of the output current disclosed by the invention, an AC component in the output current of a DC-DC switching power supply can be cancelled to obtain a good ripple suppression effect; and the ripple suppression circuit also has the advantages of few components, low cost, high efficiency and small volume.

The invention discloses a reference voltage control circuit and control method and a ripple elimination circuit of using the reference voltage control circuit. The reference voltage control circuit comprises a voltage generation circuit and a reference generation circuit, wherein the voltage generation circuit receives an input voltage signal; the input voltage signal generates a voltage drop on afirst resistor to obtain initial voltage; when the initial voltage reaches first threshold voltage or after the initial voltage reaches second threshold voltage for a period of time, the voltage generation circuit outputs a first voltage signal; and the reference generation circuit receives the first voltage signal and outputs a reference voltage signal according to the first voltage signal. According to the reference voltage control circuit and control method and the ripple elimination circuit, the output efficiency of LED load and the ripple elimination effect can be optimized.

Methods and apparatus for reducing electromagnetic interference (EMI) in power conversion stage line filter are provided herein. The method, for example, includes determining an estimated ripple voltage or estimated ripple current using a predictive model, generating a ripple cancellation signal of opposite polarity to the estimated ripple voltage or ripple current, while compensating for at least one of magnitude or phase distortions in a signal path, and injecting the ripple cancellation signal into a power supply's line filter to reduce a ripple voltage.

A primary controller applied to a primary side of a power converter includes a ripple cancellation circuit, a compensation voltage generation circuit, and a gate control signal generation circuit. The ripple cancellation circuit generates an adjustment according to a current flowing through a feedback pin of the primary controller during turning-on of a power switch of the primary side of the power converter. The compensation voltage generation circuit generates a compensation voltage of a compensation pin of the primary controller according to the adjustment, a reference voltage, and a feedback voltage of the feedback pin. The gate control signal generation circuit generates a gate control signal to the power switch to reduce an output voltage of a secondary side of the power converter according to the compensation voltage and a detection voltage.

The invention relates to a novel interleaving BUCK converter and a ripple elimination method thereof. The converter comprises (2n + 2) IGBTs, (n + 1) inductors and two capacitors, wherein n is a natural number; the two IGBTs and the inductor form a phase bridge arm, and the converter is provided with (n + 1) phase bridge arms, wherein the second-phase bridge arm to the (n + 1)-th-phase bridge arm are connected in parallel, the parallel-connected bridge arms are directly connected with the capacitor CP in parallel, and the capacitor CS is connected between the inductor LS of the first-phase bridge arm and the capacitor CP in series; the first-phase bridge arm serves as an output ripple compensation bridge arm, and the second-phase bridge arm to the (n + 1)-th-phase bridge arm serve as power bridge arms and are used for power transmission. According to the invention, the switching loss, the cost and the volume of the interleaved BUCK converter can be reduced.

The invention provides a DC-DC converter output ripple elimination technology. According to the technology, a copy of a switch part is introduced as an auxiliary power stage in a DC-DC converter circuit; a pulse width modulation signal of which the logic polarity is opposite to that in a main circuit is adopted and a ripple of which the polarity is opposite to that of a primary circuit is generated; and the output ripple is finally eliminated at an output point of the main circuit through capacitive coupling.

A method that includes deriving a first power spectral density function of a signal input to a ripple cancellation filter; deriving a second power spectral density function of a signal concurrently output from the ripple cancellation filter; frequency shaping the first power spectral density according to a spectral rejection image of the ripple cancellation filter to obtain a test power spectral density; and indicating a degraded performance of the ripple cancellation filter in the event that the test and second power spectral density functions fail to match within pre-determined criteria.

The invention discloses a ripple elimination device for a power supply of a communication system. The ripple elimination device comprises a control module and a virtual load module, wherein the control module is used for obtaining and recording the current communication power of a communication system, obtaining a current virtual load corresponding to the current communication power according to apreset power-load comparison table, generating a corresponding load control signal according to the current virtual load, and sending the load control signal to the virtual load module, and the virtual load module is used for adjusting the size of a virtual load according to the received load control signal so as to carry out load compensation on the power supply of the communication system according to the adjusted virtual load. By adopting the technical scheme of the invention, dynamic ripples of the power supply of the communication system can be eliminated, and the radio frequency signalquality and the data throughput are improved.