Abstract: 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.

Abstract: An inverter for converting an input direct current (DC) waveform from a DC source to an output alternating current (AC) waveform for delivery to an AC grid includes an input converter, an output converter, and an active filter, each of which is electrically coupled to a bus. The bus may be a DC bus or an AC bus. The input converter is configured to convert the input DC waveform to a DC or AC bus waveform. The output converter is configured to convert the bus waveform to the output AC waveform at a grid frequency. The active filter is configured to reduce a double-frequency ripple power of the bus waveform by supplying power to and absorbing power from the power bus.

Abstract: A method for selecting the optimum number of phases for a converter is provided, which selects a duty range using an input voltage and an output voltage, obtains ripple values for multiple phases in the duty range, and selects the optimum number of phases using the corresponding ripple values. The method for selecting the optimum number of phases for a converter includes a duty range selection step of selecting a duty range using an input voltage and an output voltage, a ripple value calculation step of obtaining ripple values for multiple phases within the selected duty range, a range ripple selection step of selecting one or more phases in the duty range, and a rated ripple selection step of selecting the phases having the minimum ripple value in a rated duty among the phases selected in the range ripple selection step.

Abstract: A power converter includes a small-sized inductor connected to an AC voltage input line for power factor correction and a filter for suppressing conduction noise. The inductor is connected to a rectifier and comprises first and second windings and that are wound on a common magnetic core and loosely coupled with each other. A leakage inductance component of the inductor functions as an energy storage element in a main conversion operation and an excitation inductance component of the inductor functions as a noise reduction element for suppressing an conduction noise caused by on-off operation of a switching element.

Abstract: Equipment for vehicle in accordance with the present invention includes: a vehicle-mounted unit which runs with respect to a vehicle body ground on a side of a negative electrode of a battery; an impedance component having an end connected to the vehicle body ground, and another end connected to a circuit ground; a circuit to be controlled which runs with respect to the circuit ground; a control unit which runs with respect to the circuit ground, for controlling the circuit to be controlled and for outputting a communication signal in a digital form which is to be transmitted to the vehicle-mounted unit; and a communication interface circuit which runs with respect to both the vehicle body ground and the circuit ground, for cancelling a potential difference between the vehicle body ground and the circuit ground, and for carrying out bidirectional communications between the vehicle-mounted unit and the control unit.

Abstract: A variable speed drive for an electric motor has an inverter for receiving pulse width modulation controls. The inverter communicates power signals to a poly-phase electrical motor. A resolver communicates signals from the poly-phase motor back to a motor control. The motor control includes a speed control, a field-oriented control, and a pulse width modulation drive for driving the inverter. The resolver is connected to the speed control and to the field-oriented control, and further communicates with a synchronous compensator. The synchronous compensator is configured to drive the harmonic content at a target frequency or frequencies in a selected signal towards zero over time.

Abstract: An active rectification system includes a three-level active rectifier and a pulse with modulation (PWM) control portion. The three-level active rectifier includes at least three switches, the at least three switches are selectively switchable between an upper state, a center state, and a lower state. The PWM control portion is in communication with the at least three switches, the PWM control portion is configured and disposed to create an upper carrier signal and a lower carrier signal, and the PWM control portion is configured and disposed to selectively switch the at least three switches between the upper state, the center state, and the lower state in response to a phase disposition of the upper carrier signal and the lower carrier signal.

Abstract: A method, device, and plurality of circuit enhancements for a rectifier system that enable reduction in lower order and higher order harmonics, without substantially reducing the rectifier's direct current output voltage. The rectifier system comprises a phase shifting primary transformer subsystem and a multi-pulse rectifier. At least one series impedance path is coupled to one of three input terminals/leads of the transformer subsystem and conducts one phase of three phase currents from a power supply to the transformer subsystem. The series impedance path provides low impedance to the 1st harmonic and substantially higher, inductive impedance to higher harmonics of the power supply frequency.

Abstract: A power factor correction circuit responsive to an input power supply signal at an input supply voltage is described. The circuit includes rectifier circuitry for largely performing full-wave rectification on the input supply signal to produce a full-wave rectified supply signal at a full-wave rectified voltage and a full-wave rectified current susceptible of having at least one overtone of the fundamental supply frequency. The circuit also includes a regulator for regulating the full-wave rectified voltage to produce a regulated power supply voltage with reduced voltage ripple, the regulator operating in buck-boost mode, and control circuitry for measuring at least one such overtone in the full-wave rectified current. The control circuitry also provides the regulator with a primary control signal that causes at least one such overtone to be largely removed from the full-wave rectified current.

Abstract: Methods and apparatus are provided for operation of a voltage source inverter. A method of operating a voltage source inverter having an output with multiple voltage phases having a DC voltage level, the method comprising sensing a low output frequency condition; determining a DC voltage offset responsive to the low output frequency condition; and applying the DC voltage offset when operating the voltage source inverter resulting in a change to the DC voltage level of the multiple voltage phases.

Abstract: The present invention is a polyphase, resonant switching power converter which includes a transformer structure configured for minimizing converter-frequency ripple at both an input and output of the power converter. The power converter is further configured for maximizing frequency response of an output signal provided by the power converter. The power converter further provides an electrically efficient system for providing a modulated supply voltage/power signal (ex.—the output signal) to power amplifiers which utilize EER or other techniques requiring modulated supply voltage.

Abstract: A method for providing a switching order signal to a cell of a cascaded two-level converter is provided. The cell includes a capacitor parallel-connected with two series-connected semiconductor devices. The cascaded two-level converter includes two or more of the cells cascade connected and arranged in a phase, divided into two phase arms, between a first pole and a second pole of a direct voltage side. The method includes measuring voltages of the capacitor of the cell; calculating a compensated voltage reference based on a voltage reference and the measured voltages of the capacitors, wherein the voltage reference corresponds to a desired ac current to be output on an ac-side; using the compensated voltage reference to calculate a switching order signal, and providing the switching order signal to the cells.

Abstract: Exemplary embodiments of the present disclosure provide a method and controller for damping multimode electromagnetic oscillations in electric power systems which interconnect a plurality of generators and consumers. The controller for damping such oscillations includes a phasor measurement unit (PMU) and a power oscillation damper (POD) controller. Each oscillating mode signal is damped and then superposed to derive a control signal. A feedback controller is used to feedback the control signal to a power flow control device in the power system.

Abstract: A system for moving an aircraft thrust reverser component includes a power drive unit, a thrust reverser actuator assembly, and a tertiary lock system. The power drive unit is operable to rotate and supply a rotational drive force. The thrust reverser actuator assembly receives the rotational drive force from the power drive unit and moves the thrust reverser component between a stowed position and a deployed position. The tertiary lock system selectively engages and disengages the thrust reverser component and includes a tertiary lock power unit, an electromechanical tertiary lock assembly, and a voltage limiting circuit. The voltage limiting circuit limits the voltage magnitude of a control signal supplied to the tertiary lock assembly to a predetermined value.

Abstract: A power factor correction circuit (42/44) responsive to an input power supply signal at an input supply voltage (VAC) that varies largely sinusoidally with time at a fundamental supply frequency contains regulator/control circuitry (60, 62, and 64) for measuring and removing overtones (ILDm or IFWRm) in the input supply current (ILD) or in a rectified form (IFWR) of the input supply current. Each overtone is expressible as the product of an amplitude component (Im) and a sinusoidal function (Im sin [(m+1)?ACt]) that varies with time at an integer multiple of the fundamental supply frequency. The regulator/control circuitry measures an overtone by determining the overtone's amplitude component. After generating an adjustment factor (SADJ) largely as the product of that overtone's amplitude component and an associated sinusoidal function, the regulator/control circuitry adjusts the input supply current or its rectified form by an amount corresponding to the adjustment factor for each measured overtone.

Abstract: A power converter is provided with a rectifying circuit, an inverter circuit, and a common mode filter including a common mode choke coil and a capacitor. The switching frequency of a PWM rectifying circuit is set at three times the switching frequency of a PWM inverter. Alternatively, the resonance frequency of the common mode filter is set at twice the carrier frequency of the rectifying circuit or the PWM inverter circuit or more.

Abstract: 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.

Abstract: A rotating electrical machine control device includes an inverter; a resolver; a unit; a three-phase/two-phase modulation switching unit; and a motor control unit that switches to a two-phase modulation in a specific region where an electric noise given to the resolver by a rotating electrical machine is large, even in a region where the modulation ratio is smaller than the three-phase/two-phase modulation switching boundary.

Abstract: An active electromagnetic interference (EMI) filtering may reduce the requirements for high current differential mode inductors. The active EMI filtering of the present invention may be useful in power devices that use switching power converters. Conventional EMI differential mode filtering devices may occupy up to 30% of the total weight and volume of the power electronics. Conventional differential mode filtering inductors tend to be large and heavy, especially so for high current input power lines. The present invention may replace the large conventional differential mode filtering inductors with a smaller set of coupled inductors.

Abstract: A switch-mode converter. One embodiment provides an inductive energy storage element. A rectifier arrangement is coupled to the inductive energy storage element for providing an output voltage. A switching arrangement regulates the inductive energy storage element on the basis of a control signal. A controller arrangement is configured to generate the control signal on the basis of the output voltage. The controller arrangement has a discrete-time band rejection filter and a frequency measuring arrangement.

Abstract: 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.

Abstract: A driver circuit included in a power supply having a rectifier coupled to a single phase AC input voltage is disclosed. An example driver circuit includes a drive signal generator to generate a drive signal to be coupled to a variable impedance element. A voltage sensor is coupled to the drive signal generator and is to be coupled to sense a voltage across a high voltage capacitance. The driver circuit is to be coupled to control the variable impedance element in response to the voltage sensor. A low voltage capacitance is allowed to receive current from the input if the sensed voltage is less than a second threshold value. The low voltage capacitance is prevented from receiving current from the input if the sensed voltage is greater than a first threshold value.

Abstract: In a power converter having m=two or more channels of power factor correction (PFC) circuits connected in parallel and an electromagnetic interference (EMI) filter connected in series therewith, phase shifts in switching between the respective PFC channels can allow increase of EMI filter corner frequency allowing reduction of size and cost of the EMI filter at some switching frequencies. Asymmetrical phase shifts (other than 360°/m) such as 360°/2m and other phase shifts and variations in m allow increase of EMI filter corner frequency at switching frequencies where symmetrical, 360°/m phase shifts provide no benefit to EMI filter design by providing cancellation or partial cancellation of different harmonics of the switching noise; which cancellation may be arranged to be complementary to the EMI filter function at more than one peak of the noise spectrum. (Such asymmetrical phase shifts do not significantly increase ripple and consequent switching noise).

Abstract: A power factor correction circuit (42/44) responsive to an input power supply signal at an input supply voltage (VAC) that varies largely sinusoidally with time at a fundamental supply frequency contains regulator/control circuitry (60, 62, and 64) for measuring and removing overtones (ILDm or IFWRm) in the input supply current (ILD) or in a rectified form (IFWR) of the input supply current. Each overtone is expressible as the product of an amplitude component (Im) and a sinusoidal function (Im sin [(m+1)?ACt]) that varies with time at an integer multiple of the fundamental supply frequency. The regulator/control circuitry measures an overtone by determining the overtone's amplitude component. After generating an adjustment factor (SADJ) largely as the product of that overtone's amplitude component and an associated sinusoidal function, the regulator/control circuitry adjusts the input supply current or its rectified form by an amount corresponding to the adjustment factor for each measured overtone.

Abstract: A ripple voltage suppression apparatus includes a DC/DC converter and a control circuit. The DC/DC converter has a power electronic switch. The control circuit has a voltage detector detecting a DC output voltage of the DC/DC converter, a ripple voltage suppression circuit receiving the detected DC output voltage to generate an AC control signal for controlling an AC component of a duty ratio of the power electronic switch, an output voltage regulation circuit receiving the detected DC output voltage to generate a DC control signal for controlling an DC component of a duty ratio, an adder adding the AC and DC control signals to form a combined control signal, and a PWM circuit converting the combined control signal into a PWM signal to control the power electronic switch. Only the DC output voltage of the DC/DC converter has to be detected for the control circuit.

Abstract: A power converter includes an output filter circuit including first and second inductive elements; a voltage source coupled to the output filter circuit, the voltage source for generating a voltage across the output filter circuit, the voltage including an alternating voltage component, the alternating voltage component causing the application of an alternating current to the first inductive element of the output filter circuit; and an attenuation filtering circuit.

Abstract: A power factor correction (PFC) circuit includes an inductor, a diode, a storage capacitor, a switch and a control unit. The input power has a voltage fluctuation V1. The storage component absorbs a first voltage fluctuation and a switch regulation circuit absorbs a second voltage fluctuation V2. Thus output voltage from the PFC circuit is not a conventional constant voltage but a voltage of a great ripple. The PFC circuit further has a harmonic regulation unit. The harmonic regulation unit generates a voltage signal containing 3rd harmonic. The control unit receives a feedback signal and the voltage signal containing 3rd harmonic to generate a reference to the inductor current. Therefore, the inductor current contains 3rd harmonic. Thus power fluctuation absorbed and released by the capacitor is smaller. As a result energy storage capacitance can be reduced significantly.

Abstract: Resonant transformer systems and methods of use are described. One aspect may include a primary winding, a secondary winding, and at least one output winding. In further aspects, a transformer may be coupled to the secondary winding. In one aspect, the output winding is coupled to rectifying circuitry, which may be coupled to one or more capacitors.

Abstract: A power circuit, in certain embodiments, includes an inductor to limit current through a capacitor, wherein the capacitor is configured to smooth ripple for a constant voltage welding system. More specifically, the power circuit may include a rectifier configured to convert AC power to DC power. The rectifier may be coupled to a DC bus configured to transmit the DC power. A capacitive circuit having the capacitor may be coupled across the DC bus to smooth ripple in the DC power. The inductor, e.g., coupled between the DC bus and the capacitive circuit, limits the rate of current flow between the capacitive circuit and the DC bus during a welding operation, thereby reducing heating in the output capacitive circuit. A further inductor may be coupled to one side of the DC bus to stabilize the rate of current flow from the power circuit to a load.

Abstract: One system of the present application includes an electric power generation device structured to provide an AC electric power output at a target frequency. This device includes: an electric power generator; a sensing arrangement structured to provide samples corresponding to magnitude of the AC electric power output; and a controller including operational logic responsive to the sensing arrangement to calculate a peak amplitude as a function of a waveform period corresponding to the target frequency and two of the samples separated in time by a target duration of 20 to 30 percent of the waveform period and determine a zero crossing of the output from the peak amplitude and the target frequency. The operating logic is further structured to control operation of the device in accordance with the zero crossing.

Abstract: 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.

Abstract: A frequency converter in which the inductance is reduced by enlarging the forms of bus bars which connect a P phase, an N phase of an inverter part and a positive electrode or a negative electrode of smoothing capacitors and the form of a wiring bus bar which connects an intermediate layer of capacitors which are connected in series to enlarge areas where they overlap each other, and by making currents flow in the opposite directions to each other.

Abstract: The configurations of an interleaved flyback converter and a controlling method thereof are provided. The proposed two-phase interleaved flyback converter includes a transformer including a first primary winding having a first terminal, a first secondary winding having a first terminal, a second primary winding having a second terminal, a second secondary winding having a second terminal and a magnetic coupled core device, wherein the first primary, the first secondary, the second primary and the second secondary windings are wound therein, and the first terminal of the first primary winding has a polarity the same as that of any of the first terminal of the first secondary winding, the second terminal of the second primary winding and the second terminal of the second secondary winding so as to eliminate a ripple of a channel current of the converter.

Abstract: A capacitive power supply circuit, comprising a power storage element between two output terminals for providing a rectified output voltage; in series between a first input terminal for applying an A.C. voltage and a first of the output terminals, at least one capacitor and a first diode; a switch controllable by application of a signal on a triggering terminal; and means for controlling said switch to the on state when the output voltage is in a predetermined range of values.

Abstract: A galvanic isolated DC-DC and DC-AC power conversion system is coupled to a plurality of DC sources which are derived from a combination of a plurality of single-phase and three-phase AC-DC converters. The DC-DC and DC-AC power conversion system in one embodiment is configured to provide mixed type outputs (mixed frequency, e.g. DC with 50 or 60 Hz, with 400 Hz; mixed voltage levels).

Abstract: In a multi-phase power converter, efficiency is increased and ripple reduced while maintaining transient response and dynamic performance improved by electrically coupling secondary windings of transformers or provided for inductors of respective phases such that current to a load is induced in each phase by current in another phase. Magnetic coupling can also be provided between phases using a multi-aperture core of a configuration which minimizes primary winding length and copper losses. Efficiency at light load is enhanced by controlling current in the series connection of secondary windings in either binary or analog fashion.

Abstract: A power factor controller for a switching power supply, that in one embodiment couples a power factor control circuit between an AC input and an output wherein a digital controller computes circuit currents for regulating the power supply without direct current measurements.

Abstract: Power supply circuit for LCD backlight and method thereof are disclosed in the present invention. The power supply circuit includes a power bus, a boost converter, a buck converter and a controller. The power bus supplies power to a load. The boost converter and buck converter are coupled to the power bus respectively for storing the power from the power line and restoring the power to the load. A controller is further coupled to the buck and boost converter for enable them alternatively according to a pulse width modulation (PWM) signal.

Abstract: The invention recognizes that filter size can be reduced substantially as power factor is permitted to deviate below unity in systematic ways. Preferred methods of the invention provide specific, computable waveforms that permit use of a minimum filter size given a desired target power factor.

Abstract: An unregulated isolated DC/DC converter is configured to receive an input signal and to provide an output signal. A ripple control circuit is coupled to the unregulated isolated DC/DC converter, wherein the ripple control circuit is configured to reduce an amount of low frequency ripple transferred to the output signal from the input signal.

Abstract: The invention relates to a method for power control of an electric motor, in particular a motor for driving the suction fan of a vacuum cleaner connected to an AC mains power supply. The power control is effected by varying the phase angle of the electric alternating quantity supplied to the motor by the use of semiconductor switches. AC power supplied to the motor is switched by using different delay times for the switching in each half-period of a full AC period to suppress odd harmonics, particularly the third harmonic of the mains power line frequency. Half-periods of a full period are mirrored in the next consecutive full period in order to suppress even harmonics, particularly the second harmonic of the mains power line frequency. A set of delay times t1 and t2 are defined and selected to be used in further avoiding critical delay time areas for harmonics and minimize the generation of vibrations.

Abstract: A rectifier system, in particular a rectifier bridge for a three-phase generator, includes a plurality of rectifier elements, specifiable rectifier elements being different from the other rectifier elements in at least one property. The rectifier elements are, for example, diodes which differ from one another with regard to the following properties: switching time or the reverse recovery switching time and/or current density and/or chip area and/or chip thickness and/or the breakdown voltage and/or internal resistance and/or path resistance and/or with regard to another property which is suited for reducing ripple.

Abstract: A polygon connected autotransformer in conjunction with zero sequence blocking inductor(s) enables multipulse AC to DC converters to use lower kVA parts rating by using appropriate phase-shifted voltage sets in conjunction with inductors that extend the conduction period and reduce rms current. Also, lower harmonic voltages in the transformer facilitate use of lower performance magnetic steel. Designs for 12, 18, and 24-pulse use the same conceptual approach. Very efficient high power ratings are feasible. Means are given to limit the maximum no-load DC output voltage. A technique is disclosed that reduces the size of polygon transformers supplying loads with substantial third harmonic.

Abstract: According to one embodiment, the switching power supply device comprises a DC-DC converter, an alternating current driver circuit, a smoothing capacitor and control circuitry. The control circuitry operates for adjusting a phase of an oscillation signal from the alternating current driver circuit to coincide start time points of current conducting periods between the output stage of the DC-DC converter and an input stage of the alternating current driver circuit.

Abstract: An engine diagnostic system is provided that enables a service technician to evaluate engine cylinder contribution to output power. The service technician couples one or more signal leads to the vehicle's battery, alternator, or accessory receptacle (e.g., cigarette lighter receptacle) to provide an alternator output signal to a signal analyzer. The signal analyzer processes the alternator output signal to generate an engine signature, which represents engine cylinder contribution to engine output power.

Abstract: A system and method are provided to increase the horsepower of an induction motor. One technique for increasing the horsepower of a motor is to connect the motor to a variable speed drive that is providing an output voltage and frequency greater than the standard line voltage and frequency. The connection of the variable speed drive to the induction motor enables the motor to be operated in constant flux or constant volts/Hz mode and provide a greater output horsepower. Another technique for increasing the horsepower of a motor is to use a dual voltage motor configured for lower voltage operation and then provide the motor with the corresponding voltage and frequency for higher voltage operation. The higher voltage and higher frequency can be provided by a variable speed drive with or without voltage boost. A variable speed drive without voltage boost, but with frequency boost, can be used in situations where the standard main voltage is greater than the lower voltage rating.

Abstract: A motor drive system control provides global closed loop feedback to cooperatively operate system components to adaptively reduce noise and provide noise cancellation feedback. An active EMI filter reduces differential and common mode noise on an input and provides a noise level indication to a system controller. Power switches in both a power converter and power inverter are cooperatively controlled with dynamic dv/dt control to reduce switching noise according to a profile specified by the controller. The dv/dt control is provided as an analog signal to a high voltage IC and codified as a pulse width for a level shifting circuit supplying control signals to the high voltage gate drive. A noise extraction circuit and technique obtain fast noise sampling to permit noise cancellation and adaptive noise reduction.

Abstract: A circuit that includes a filter and a DC bus is provided that reduces the potential for failure of a second capacitor of the filter in the event a first capacitor shorts. The filter is electrically connected across the DC bus and includes serially connected capacitors and a capacitor fuse electrically connected in series with the capacitors. The capacitor fuse is adapted to open in the event a first capacitor of the series shorts in order to prevent failure of a second capacitor of the series. In one embodiment of the invention, a static power converter includes a pair of serially connected capacitors having a DC bus fuse serially connected therewith. In another embodiment of the invention, a filter connected across a DC bus includes a plurality of capacitor legs that each include a capacitor fuse serially connected to a plurality of serially connected capacitors.

Abstract: A SEPIC type voltage converter (101) comprises a transformer (40) having a primary winding (41) and a storage capacitor (33) connected in series, and a controllable switch (51) coupled in parallel with said series combination. The transformer has a first secondary winding (421) and a first rectifying diode (431) connected in series, and a first capacitor (441) coupled in parallel with said series combination, one terminal of said first capacitor (441) being coupled to an output terminal (451). The voltage converter also comprises feedback means (50; 53, 52) coupled to said output terminal (451) and controlling said controllable switch (51). The transformer further has a second secondary winding (62) and a second rectifying diode (63) connected in series, wherein this series combination is also coupled to said output terminal (451) in order to limit the voltage across the storage capacitor.

Abstract: This invention provides a power supply device capable of widening a conduction period of an input current by a simple control to improve a power factor, and reducing a harmonic distortion of the input current The power supply device comprises a rectifier circuit, a reactor, a power factor correction circuit having switching elements, capacitors and a reverse-current blocking rectifier elements, a smoothing capacitor for smoothing an output voltage of the power factor correction circuit to obtain a DC voltage, a pulse signal controller generating and outputting a pulse signal for turning on and off the switching elements, and a driver for receiving the pulse signal to drive a switching elements of the power factor correction circuit.