4236results about "Apparatus with intermediate ac conversion" patented technology

A power subsystem is actively optimized to improve total subsystem efficiency in a way that is responsive to changes in load requirements, power supply variations, and subsystem temperature variations. Detailed, multidimensional power loss models are developed for constituent devices which are then combined into a power subsystem containing a controller and circuity for measuring device operating parameters such as input and output voltage, output current, and temperature. Operating parameters are continually monitored, and set points are correspondingly changed based on the detailed power loss models to achieve maximum overall efficiency for the instantaneous operating state of the system.

A system, method and apparatus for contact-less charging of battery operated devices, including a host charger with a power converter and resonant tank circuit and a portable device where the battery is located, with a battery charging control IC, wherein the method obviates the need for a voltage controller in each of both the host and the portable stages. The charging of the battery in the portable device is controlled by a charging controller therein, which is in continual electric communication with the host, whose output power the control IC dynamically monitors and controls. In one embodiment, component count is minimized but battery charging is not optimized when the battery voltage is very low. In the other embodiment, charging efficiency is maximized regardless of the output voltage of the battery.

The present invention provides methods and apparatus for reducing power consumption. One method includes detecting the presence of an object, identifying whether the object is a valid device and restricting power if its not a valid device. Another method includes temporarily applying a low amount of power to the primary unit to detect a load, supplying more power to determine if its a valid secondary device, and restricting power if its not. An apparatus for reducing power consumption includes two power inputs, where the lower power input powers a sense circuit. A switch selectively decouples the higher power input from the primary subcircuit during detection mode and couples the higher power input to the primary subcircuit during power supply mode.

A power transmission device includes: a transmission means including at least an oscillation means and a resonant means and for transmitting power to a power reception device by using a magnetic resonance-type power transmission technique; and a control means for controlling the reception power of the power reception device so as to be at a maximum by changing at least one of an oscillation frequency of the oscillation means and a resonant frequency of the resonant means.

Disclosed is a noncontact electric power transmission system having a power transmitter circuit section 10 and a power receiver circuit section 30 which are adapted to be coupled to transmit electric power from a transmitter coil Lp provided in the power transmitter circuit section 10 to a receiver coil Ls provided in the power receiver circuit section 30, in a noncontact manner by means of electromagnetic induction. The noncontact electric power transmission system comprises: a separately-excited or self-excited switching circuit 2 provided in the power transmitter circuit section 10; a control IC 3 operable to drive the switching circuit 2; an LC series resonant circuit including a capacitor Cp connected in series to the transmitter coil Lp or an LC parallel resonant circuit including a capacitor Cp connected in parallel to the transmitter coil Lp; and an LC parallel resonant circuit including a capacitor Cs connected in parallel to the receiver coil Ls, wherein an oscillating frequency (Fosc) of the control IC 3, a resonant frequency (Fpr) of the LC series resonant circuit or the LC parallel resonant circuit in the power transmitter circuit section 10, and a resonant frequency (Fsr) of the LC parallel resonant circuit in the power receiver circuit section 30, have the following relationship: Fpr<Fosc<Fsr.

Apparatuses and methods include a photovoltaic energy production unit to generate electricity. A local management unit is coupled between the photovoltaic energy production unit and a connection of energy production units forming a string bus. The local management unit includes a controller and switching circuitry. The controller provide a control for the switching circuitry to deliver electrical energy to the string bus. A communication transmission modulator is associated with the local management unit. The communication transmission modulator modulates the control with data to be transmitted from the local management unit over the string bus.

An electrical DC-to-AC power conversion apparatus is disclosed that is primarily intended for use with solar photovoltaic sources in electric utility grid-interactive applications. The invention improves the conversion efficiency and lowers the cost of DC-to-AC inverters. The enabling technology is a novel inverter circuit topology, where throughput power, from DC source to AC utility, is processed a maximum of 1½ times instead of 2 times as in prior-art inverters. The AC inverter output configuration can be either single-phase, split-phase or poly-phase.

An AC controller which provides programmable switching of AC power flow, together with producing a source of DC power for operating the AC controller. The AC controller is connected in series with only one side of the AC power source and the AC load. The AC controller utilizes a thyristor for AC power control switching. During the operation, the AC controller steals a small portion of each half-cycle of the AC power to provide DC power to the AC controller. The AC controller enables the flow of AC current by providing a gate current pulse at any predetermined time during the half cycle. Once the thyristor is ON, the AC current flows through the thyristor until the AC cycle is at or near zero. To provide an OFF state, the AC controller does not provide a gate current pulse. The AC controller uses an microcontroller for the programmable capability. The AC controller can be programmed to provide a flashing light function, a time delay off mode, an automatic fade mode, a dimming function, a burglar deterrent function, and a time delay dim function. With a three-position switch which can replace existing types of wall switches, three modes of operation are achieved: ON, OFF, and MODE. The mode position initiates operation of the special function of the controller.

A bidirectional active power conditioner includes a DC side, a bidirectional DC / DC power converter, a DC / AC inverter and an AC side. The DC side electrically connects with a DC source while the AC side electrically connects with a load and an AC source. The bidirectional DC / DC power converter is controlled via high-frequency pulse width modulation (PWM) switching so as to generate a predetermined DC voltage or DC current while the DC / AC inverter is controlled to convert the predetermined DC voltage or DC current into a predetermined AC voltage or AC current.

A power supply including a regulation circuit that maintains an approximately constant load current with line voltage. An example circuit includes a switch including first, second and third terminals. The first terminal is coupled or decoupled to the second terminal in response to a control signal received at the third terminal. Voltage sense circuitry is included and is coupled to sense a voltage drop across the switch. The voltage drop is representative of a current in the switch during an on time of the switch. The voltage sense circuitry has a variable current limit threshold that increases between a first level and a second level during the on time of the switch. The control signal is responsive to the variable current limit threshold to regulate a power supply with an output characteristic having an approximately constant output voltage below an output current threshold and an approximately constant output current below an output voltage threshold.

A DC power supply device includes transformers that operate with an enhanced efficiency and can reduce the factors that generate ripples in the output voltage to make it possible to downsize the transformers and the smoothing filters of the device, reduce the loss attributable to the switching elements during its constant power output operation and also downsize the heat sink fins so that the overall dimensions of the power supply device may be reduced. The DC power supply device also comprises a pair of switching changers, two output transformers and two rectifying / smoothing sections for rectifying the respective outputs of the switching changers. Each of the two switching changers has the same switching cycle period and the striking phases of the switching elements of one of the switching changers and those of the switching elements of the other switching changer are made variable. Then, a constant power output level is achieved by utilizing the difference of the striking phases of the two switching changers in order to isolate the switching changers from each other for operation and connect them in series or in parallel for operation.

A vertical winding structure for planar integrated magnetics used in switched-mode power converters maintains close coupling between the different windings but reduces the eddy current losses, lowers the DC winding resistance and reduces the number of layers of the PCB. Vertical and horizontal windings can be used together without sacrificing these performance advantages and further minimizing the capacitive coupling between the outer-leg windings and the center-leg winding. This winding structure can be used in a wide range of magnetic structures including isolated and non-isolated CDRs, interleaved CDRs, and buck and boost converters.

Apparatuses and methods include a photovoltaic energy production unit to generate electricity. A local management unit is coupled between the photovoltaic energy production unit and a connection of energy production units forming a string bus. The local management unit includes a controller and switching circuitry. The controller provide a control for the switching circuitry to deliver electrical energy to the string bus. A communication transmission modulator is associated with the local management unit. The communication transmission modulator modulates the control with data to be transmitted from the local management unit over the string bus.

A DC-DC converter apparatus comprising half or full bridge, two-stage resonant converter, which may include series resonant (inductor, capacitor) devices. An isolated transformer having primary and secondary winding supplies current to full-wave secondary stage-bridge through the use of primary winding resonant devices employing primary stage-bridge. The magnetizing of said devices employs zero-current, zero-voltage resonant-transition switching technology, which reduces switching losses at all switching frequencies to almost zero. The regulation of output voltage at all loads and input voltages achieved by the control of the switching frequency and the phase between signals for primary and secondary stages. The proper intermittent of the frequency and the phase allows achieving the value of efficiency up to 97%.

A method and apparatus for anti-islanding of distributed power generation systems having an inverter comprising a phase locked loop (PLL), a phase shift generator for injecting a phase shift into the PLL during at least one sample period, and a phase error signature monitor for monitoring at least one phase error response of the PLL during the at least one sample period.

An electric arc welder with a variable AC voltage input of up to 600 VAC and a rectifier to provide a DC link, a driven high frequency boost stage with first and second leads connected to the DC link. The boost stage comprises an inductor, a first series output branch with a first primary winding connected to the first lead and a first capacitor connected to the second lead, a second series output branch with a second primary winding connected to the second lead and a second capacitor connected to the first lead and a high frequency operated switch between the leads and having an opened condition charging said capacitors by current through the primary windings in a first direction and discharging the inductor and a closed condition charging the inductor through the primary windings by current in a second direction and discharging the inductor to charge the capacitors. The switch is operated by a power factor control circuit at a frequency greater than about 18 kHz. The boost stage has an AC output stage comprising the secondary winding network of a transformer powered by current flow in the first and second primary windings. An output rectifier converts said AC output to a first DC voltage. At the final portion of the welder an output converter converts the first DC voltage to a second DC voltage connected across the arc of a welding station and having a controlled weld current or voltage.

The present invention provides methods and apparatus for reducing power consumption. One method includes detecting the presence of an object, identifying whether the object is a valid device and restricting power if its not a valid device. Another method includes temporarily applying a low amount of power to the primary unit to detect a load, supplying more power to determine if its a valid secondary device, and restricting power if its not. An apparatus for reducing power consumption includes two power inputs, where the lower power input powers a sense circuit. A switch selectively decouples the higher power input from the primary subcircuit during detection mode and couples the higher power input to the primary subcircuit during power supply mode.

A circuit that utilizes most of the energy stored in the bulk capacitor of an AC to DC or DC to DC converter power supply by providing an intermediate converter between a first stage boost converter and a DC-DC converter. When the bulk voltage starts to fall during the hold-up time, the intermediate converter boosts the falling voltage to maintain the regulated DC input to the DC to DC converter while reducing the operating range and increasing the operating duty cycle, so as to increase efficiency, reduce peak current and voltage stresses. The circuit also reduces the size of the output filter components and reduces the size of the bulk capacitance by up to half.

A single-stage input-current-shaping (S<2>ICS) flyback converter achieves substantially reduced conduction losses in the primary side of the S<2>ICS flyback converter by connecting a bypass diode between the positive terminal of a full-bridge rectifier and the positive terminal of an energy-storage capacitor. An effective current interleaving between an energy-storage inductor and the bypass diode is thus obtained in the S<2>ICS flyback converter around the peak of the rectified line voltage, resulting in a significantly reduced input-current ripple and reduced current stress on the switch. Further, by rearranging the rectifiers in the ICS part of the S<2>ICS flyback converter in such a way that the energy-storage capacitor and the ICS inductor are connected to the ac line voltage through only two rectifiers, one diode forward-voltage drop is eliminated, which results in a substantially reduced conduction loss in the primary-side rectifiers.

A regulated power factor corrected power supply apparatus is provided. The apparatus includes an input rectifier circuit for receiving an input AC voltage and outputting a full-wave rectified DC voltage. A single-stage isolated buck-type converter is coupled with the input circuit. The converter circuit comprises an isolated buck-type converter circuit including an isolation transformer. An output rectifier and semiconductor tap switch are coupled to a secondary winding of the isolation transformer. The tap switch couples a larger portion of the secondary winding to an output bulk capacitor during the portions of the input sinewave half-cycle, which are low in amplitude. The tap switch enables the single-stage isolation buck-type converter to operate over a much larger portion of the input sinewave, but also allows the converter to operate at high-efficiency over the majority of the input sinewave.

The configurations of a parallel-connected resonant converter circuit and a controlling method thereof are provided in the present invention. The proposed circuit includes a plurality of resonant converters, each of which has two input terminals and two output terminals, wherein all the two input terminals of the plurality of resonant converters are electrically series-connected, and all the two output terminals of the plurality of resonant converters are electrically parallel-connected.

The present invention relates to a switch mode power supply and a driving method for reducing switching loss and audible noise in the burst mode. The switch mode power supply includes a main switch, a power supply, an output unit, and a switch controller. The power supply includes a transformer having a primary coil connected to the main switch, and supplies power to a secondary coil of the transformer according to the operation of the main switch. The output unit is connected to the secondary coil of the transformer and outputs power supplied to the secondary coil of the transformer. The switch controller receives a feedback signal corresponding to the output voltage of the output unit, a sense signal corresponding to the current flowing to the main switch, and a sync signal corresponding to the voltage difference at the main switch, controls the on / off of the main switch, and determines whether to start the burst mode by using the feedback signal, and maintains the switching operation forcibly off period in the burst mode so that the reference frequency of burst switching may be less than a predetermined value.

The invention relates to a series resonance DC / DC converter of a photovoltaic system, which comprises a single-pole converter (40), a series resonance circuit (50), a high-frequency isolation transformer (16) and a rapid uncontrollable rectifier (20), wherein the single-pole converter (40) is used for converting a direct voltage (26) of a photovoltaic array (10) into a single-pole pulse voltage; the series resonance circuit (50) is used for converting the single-pole pulse voltage into a sine voltage with a fixed frequency; the high-frequency isolation transformer (16) is used for boosting and isolating as well as protecting; and the rapid uncontrollable rectifier (20) is used for rectifying the high-frequency sine voltage into a stable direct current voltage (28). The converter (100) is only provided with two switching elements, has the advantages of simple control mode and no switching loss, and can be used for boosting and stabilizing the larger photovoltaic array so as to be convenient for synchronizing through a three-phase converter or charging a storage battery.

A power converter is installed for each solar cell, and electric power having a low voltage and a relatively large electric current is input to the power converter, thereby reducing as much as possible the wiring work which greatly raises the cost of an electric power generator. For this purpose, a power converter which has a high operating efficiency and by which a low-cost electric power generator can be constructed when an unstable power source such as a solar cell is used is desired. As this power converter, a DC / DC converter is provided which supplies DC power supplied from the solar cell to a transformer by switching the DC power, thereby boosting the output voltage from the solar cell by a few tens of times to a few hundred times. The number of turns of the primary winding of the transformer is set to 2 or 3.

A power-receiving-side control circuit of a power reception device performs intermittent load modulation by causing an NMOS transistor to be turned ON / OFF during normal power transmission. A power-transmission-side control circuit included in a power transmission control device of a power transmission device monitors, an intermittent change in the load of the power reception device during normal power transmission. The power-transmission-side control circuit determines that a foreign object has been inserted between a primary coil and a secondary coil and stops power transmission when an intermittent change in load cannot be detected. The amount of power supplied to the load may be compulsorily reduced when the load state of the load is heavy.

A current resonant DC-DC converter of multi-output type is provided which comprises an output-regulatory MOS-FET 40 connected between a secondary winding 5c of a transformer 5 and a smoothing capacitor 16 in a second rectifying smoother 17, and an output control circuit 41 for controlling the on-off operation of output-regulatory MOS-FET 40 based on voltage VO2 from smoothing capacitor 16 in second rectifying smoother 17. By turning the on-off operation of output-regulatory MOS-FET 40 in synchronization with switching frequency of first or second MOS-FETs 1, 2, an ideal cross regulation among respective DC outputs can be obtained, providing the inexpensive converter with simple circuit alteration capable of producing highly stable DC outputs with high power conversion efficiency, high accuracy and less power conversion loss.

A power factor corrected boost converter circuit includes a rectifier connectable to an ac input and having a rectified dc output provided across a dc bus, an inductor having first and second terminals connected in one leg of the dc bus, an integrated circuit comprising a control circuit for controlling a switch, the integrated circuit including a housing enclosing the control circuit, the integrated circuit having a power terminal, a ground terminal, a first control input terminal coupled to an output of the converter circuit, and a second control input terminal coupled to a sensor for sensing current in the dc bus and further having an output terminal connected to the switch, a boost rectifier diode having a first terminal, the diode coupled to the inductor, and a storage capacitor connected to the diode. The control circuit comprises a one cycle control circuit having an integrator reset by a clock signal for each cycle of the clock signal. The circuit further includes any or all of an inrush current limiting circuit for limiting the current through the inductor to a value below a predetermined level, a fan motor speed controller and a housekeeping power supply controller.

A vertical winding structure for planar integrated magnetics used in switched-mode power converters maintains close coupling between the different windings but reduces the eddy current losses, lowers the DC winding resistance and reduces the number of layers of the PCB. Vertical and horizontal windings can be used together without sacrificing these performance advantages and further minimizing the capacitive coupling between the outer-leg windings and the center-leg winding. This winding structure can be used in a wide range of magnetic structures including isolated and non-isolated CDRs, interleaved CDRs, and buck and boost converters.