10446results about "Ac-dc conversion without reversal" patented technology

A synchronous bi-directional active power conditioning system (11) suitable for wide variable frequency systems or active loads such as adjustable speed drives which require variable voltage variable frequency power management systems is disclosed. Common power electronics building blocks (100, 200) (both hardware and software modular blocks) are presented which can be used for AC-DC, DC-AC individually or cascaded together for AC-DC-AC power conversion suitable for variable voltage and / or wide variable frequency power management systems. A common control software building block (2, 5) includes a digital control strategy / algorithm and digital phase lock loop method and apparatus which are developed and implemented in a digital environment to provide gating patterns for the switching elements (3, 6) of the common power-pass modular power electronics building blocks (100, 200).

This invention relates to a power module for a plug-in hybrid electric vehicle including an integrated converter having a rectifier changing AC to DC, a DC / DC converter changing from a first voltage to a second voltage, and a battery storing electrical energy. The integrated converter operates in three modes 1) AC plug-in charging mode, 2) boost mode supplying power from the battery to the electrical bus and 3) buck mode supplying power from the electrical bus to the battery. The integrated converter utilizes the same single inductor during each of the three operating modes to reduce cost and weight of the system.

The present invention relates to synchronized vibration devices that can provide haptic feedback to a user. A wide variety of actuator types may be employed to provide synchronized vibration, including linear actuators, rotary actuators, rotating eccentric mass actuators, and rocking mass actuators. A controller may send signals to one or more driver circuits for directing operation of the actuators. The controller may provide direction and amplitude control, vibration control, and frequency control to direct the haptic experience. Parameters such as frequency, phase, amplitude, duration, and direction can be programmed or input as different patterns suitable for use in gaming, virtual reality and real-world situations.

An active rectifier and a wireless power reception apparatus using the same are disclosed herein. The active rectifier includes first and fourth switches, second and third switches, and a synchronization control unit. The first and fourth switches are turned on while the voltage of an alternating current (AC) input is negative, and apply the current of the AC input to a rectifying capacitor. The second and third switches are turned on while a voltage of the AC input is positive, and apply the current of the AC input to the rectifying capacitor. The synchronization control unit compensates for the delay time of the comparator for detecting zero-crossing of the AC input so as to switch the first to fourth switches.

It is an object of the present invention to provide a rectifier circuit that can suppress deterioration or dielectric breakdown of a semiconductor element due to excessive current. A rectifier circuit of the present invention includes at least a first capacitor, a second capacitor, and a diode which are sequentially connected in series in a path which connects an input terminal and one of two output terminals, and a transistor. The second capacitor is connected between one of a source region and a drain region and a gate electrode of the transistor. Further, the other one of the source region and the drain region and the other one of two output terminals are connected each other.

A novel integrated rectifier and boost converter circuit architecture is disclosed. The rectifier architecture includes a plurality of identical half-bridge rectifiers connected to receiving antennas to convert wireless AC power into DC power. The integrated rectifier may be coupled in series with a charging inductor in a boost converter. The inductor may discharge upon operation of two micro-controller-driven switching transistors using predetermined threshold and timing scheme to turn on / off. The rectifier architecture may provide high power densities, improve efficiency at larger load currents, and may be enabled in an integrated circuit with eight RF signal inputs, eight half-bridge rectifiers, and eight DC outputs ganged together as single feed into the boost converter. The rectifier circuit topology may include a comparator driven by the boost controller with a proprietary algorithm which suits control for a maximum power point tracking functionality, and an external micro-controller for additional control of the boost converter.

The AC output from a source is rectified and applied to a resistor / Zener diode circuit connection which determines the magnitude of the rectified voltage applied via a circuit to a first MOSFET device. The inverted output of the first MOSFET device is applied to the gate electrode of a second MOSFET device in a manner such that the second MOSFET device is ON even when the AC output passes through zero. The output of the second MOSFET device is connected to a resistor which determines the magnitude of the load applied to the dimmer.

Reliability enhanced systems are shown where an short-lived electrolytic capacitor can be replaced by a much smaller, perhaps film type, longer-lived capacitor to be implemented in circuits for power factor correction, solar power conversion, or otherwise to achieve DC voltage smoothing with circuitry that has solar photovoltaic source (1) a DC photovoltaic input (2) internal to a device (3) and uses an enhanced DC-DC power converter (4) to provide a smoothed DC output (6) with capacitor substitution circuitry (14) that may include interim signal circuitry (28) that creates a large voltage variation for a replaced capacitor (16). Switchmode designs may include first and second switch elements (17) and (18) and an alternative path controller (21) that operates a boost controller (22) and a buck controller (23) perhaps with a switch duty cycle controller (32).

A power scavenging device attaches to an overhead power cable and a support pole. The power scavenging device includes a non-conducting outer body and a first capacitor and a second capacitor that are connected in series forming a voltage divider. A voltage source converter is electrically connected to the output of the power scavenging device. The voltage source converter outputs a regulated power.

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).

A control circuit for a switching DC / DC Converter comprising: an input for an indicator signal indicative of an output current level from said converter; a peak detector for detecting and storing a maximum value of said indicator signal; a comparator element for comparing an instantaneous value of said indicator signal with said stored maximum value, and for generating a switching signal when said instantaneous value becomes less than a predetermined fraction of said stored value; reinitializer means for reinitializing said peak detector in response to said switching signal; and means for generating a control signal that switches between a state in which it increases over time and a state in which it decreases over time in response to said switching signal. A control module for photovoltaic generator, the module including such a control circuit, and a photovoltaic generator system comprising a plurality of such modules, each controlling a respective photovoltaic generator.

Synchronous rectifier circuit topologies for a wireless power receiver receiving a supply of power from a wireless transmitter are disclosed. The synchronous rectifier circuit topologies include a half-bridge diode-FET transistor rectifier for rectifying the wireless power into power including a DC waveform, using a control scheme that may be provided by a delay-locked loop clock, or phase shifters, or wavelength links to control conduction of FET transistors in the synchronous rectifier circuit topology, and maintaining a constant switching frequency to have the diodes, coupled to FET transistors, to allow current to flow through each one respectively at the appropriate timing, focusing on high conduction times. The synchronous rectifier circuit topologies may enable power transfer of high-frequency signals at enhanced efficiency due to significant reduction of forward voltage drop and lossless switching.

An object of the present invention is to provide a photovoltaic power generation system which is capable of achieving system linkage of a plurality of solar cell strings having different output voltages to a commercial electric power system with ease, and which enables efficient use of the maximum output electric power. It is a photovoltaic power generation system characterized by disposing voltage regulating means that regulates a DC voltage outputted from non-standard solar cell string between a standard solar cell string and electric power converting means, and regulating an output voltage of the non-standard solar cell string to the side of an output voltage of the standard solar cell string by the use of the voltage regulating means.

A system supplies electrical power to a remote electrical device. The system includes an AC / DC voltage converter coupled to the AC voltage source for converting an AC voltage from the AC voltage source to a high DC voltage output at a first location. The AC / DC voltage converter comprises a plurality of AC / DC voltage converter components which, on the input side thereof, are connected in parallel with the AC voltage source and which, on the output side thereof, are connected serially to an electric conductor. The electric conductor extends to a plurality of voltage converters at a remote location having inputs connected serially to the electrical conductor and having outputs providing an appropriate voltage to the electrical device, the plurality of voltage converters converting the high DC voltage to either a lower DC voltage or an alternating voyage without a cooling mechanism that would otherwise be needed when less than the plurality of voltage converters are implemented to convert the high DC voltage to the lower DC voltage or alternating voltage.

An AC-to-DC power converter that is capable of generating a regulated, isolated DC voltage output from a power factor corrected AC voltage input with improved efficiency. The AC-to-DC power converter is a two-stage power converter including a PFC stage connected in series to a power conversion stage. The PFC stage performs power factor correction using a zero current switching technique, and the power conversion stage includes a zero voltage switched half-bridge converter. The power conversion stage includes a transformer for providing the isolated DC voltage output. The AC-to-DC power converter includes a single feedback control loop for transferring error information from the DC voltage output to the PFC stage, thereby obtaining regulation of the DC voltage output.

The present invention provides_a power converter that can be used to interface a generator (4) that provides variable voltage at variable frequency to a supply network operating at nominally fixed voltage and nominally fixed frequency and including features that allow the power converter to remain connected to the supply network and retain control during supply network fault and transient conditions. The power converter includes a generator bridge (10) electrically connected to the stator of the generator (4) and a network bridge (14). A dc link (12) is connected between the generator bridge (10) and the network bridge (14). A filter (16) having network terminals is connected between the network bridge (14) and the supply network. A first controller (18) is provided for controlling the operation of the semiconductor power switching devices of the generator bridge (14). Similarly, a second controller (46) is provided for controlling the operation of the semiconductor power switching devices of the network bridge (14). The first controller (18) uses a dc link voltage demand signal (VDC13 GEN*) indicative of a desired dc link voltage to control the semiconductor power switching devices of the network bridge (10) to achieve the desired level of dc link voltage that corresponds to the dc link voltage demand signal (VDC13 GEN*). The second controller (46) uses a power demand signal (P*) indicative of the level of power to be transferred from the dc link to the supply network through the network bridge (14), and a voltage demand signal (VTURB*) indicative of the voltage to be achieved at the network terminals of the filter (16) to control the semiconductor power switching devices of the network bridge (14) to achieve the desired levels of power and voltage that correspond to the power and voltage demand signals (P* and VTURB*).

A two-wire load control device (such as, a dimmer switch) is operable to control the amount of power delivered from an AC power source to an electrical load (such as, a high-efficiency lighting load) and has substantially no minimum load requirement. The dimmer switch includes a bidirectional semiconductor switch, which is operable to be rendered conductive each half-cycle and to remain conductive independent of the magnitude of a load current conducted through semiconductor switch. The dimmer switch comprises a control circuit that conducts a control current through the load in order to generate a gate drive signal for rendering the bidirectional semiconductor switch conductive and non-conductive each half-cycle. The control circuit may provide a constant gate drive to the bidirectional semiconductor switch after the bidirectional semiconductor switch is rendered conductive each half-cycle. The bidirectional semiconductor switch may comprise, for example, a triac or two field-effect transistors coupled in anti-series connection.

In a power factor corrected AC-to-DC power supply system, a DC-to-DC power converter is coupled to the output of an AC-to-DC power converter in order to produce a regulated DC output signal from a rectified AC input signal. The AC-to-DC power converter and the DC-to-DC power converter each includes a switch for controlling the operation of their respective power converter. The AC-to-DC converter includes an inductor. The system provides power factor correction for minimizing harmonic distortion by including a controller that receives the regulated DC output voltage as a feedback signal, and in response, produces a series of drive pulses having predetermined constant duty cycle. These pulses are simultaneously fed to each switch, to operate the respective converters alternately between ON and OFF states. When the AC-to-DC converter is driven by a fixed duty cycle of the series of pulses, power factor correction is improved since the current flowing through the inductor is substantially proportional to the waveform of the rectified AC input signal. By preselecting the value of the inductor, the AC-to-DC converter is operable in a discontinuous mode when the instantaneous rectified AC input signal is low and in a continuous mode when the instantaneous rectified AC input signal is high.

A DC output power converter or DC switch device that includes methods and apparatus to reverse the current in the connected load, thereby draining the load's energy until the voltage in the load is brought to a (near) zero potential and held there.

Power factor correction apparatus, for a switching power supply fed by an array of rectifying diodes and consisting of at least an input inductor, a contact of which is connected in series with a contact of the array, and of a power switch connected between the other contact of the array and the other contact of the input inductor that comprises circuitry for identifying, in each cycle determined by the switching frequency of the power supply, whenever the instantaneous value of the current through the inductor reaches a minimal value; circuitry for switching the power switch to its conducting state in response to the minimal current through the inductor; circuitry for reflecting the current flowing through the inductor by a measurable or simulated parameter; and circuitry for providing indication, in each cycle, by using the parameter, the indication being related to the timing until the peak value of the current, that corresponds to a specific load, has been essentially reached, or to the time from the moment that the current reaches the minimal value until the timing, and for switching the power switch to its non-conducting state in response to the indication.

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 modular HVDC converter system including a high voltage direct current network, and at least two DC / AC converters being connected in series to the HVDC network. Each of the DC / AC converters is arranged to provide AC to a separate AC load.

The AC output from a source is rectified and applied to a resistor / Zener diode circuit connection which determines the magnitude of the rectified voltage applied via a circuit to a first MOSFET device. The inverted output of the first MOSFET device is applied to the gate electrode of a second MOSFET device in a manner such that the second MOSFET device is ON even when the AC output passes through zero. The output of the second MOSFET device is connected to a resistor which determines the magnitude of the load applied to the dimmer.

There is disclosed a core structure with a very low profile, high power density and lower losses. Higher core surface area and improved core utilization in terms of flux density are other desirable feature in the disclosed design. The disclosed design also allowed for a larger core area where the DC fluxes are added, thereby reducing the air-gap requirements in the cores derived from low saturation density materials such as ferrites. The cellular nature of the design can also be effectively employed in vertically packaged power converters and modules.