2804results about "Electric power transfer ac network" patented technology

A system including associated equipment for transmitting radio-frequency power line carrier signals on high voltage ac or dc transmission lines within a multi-conductor bundle, one path for which is provided by one or more conductors located at the center of the bundle, and the other by the remaining conductors connected in electrical parallel and arrayed in a generally circular pattern around the center. Insulated conductor spacers hold the conductors in their symmetrical configuration and insulate the center conductor, allowing it to serve as a radio frequency path similar to that in a conventional coaxial cable. The system provides low attention, low vulnerability to external noise and low radiation of the carrier signal while providing redundant channels—three for ac transmission lines and two for bipolar dc transmission lines.

A load control system comprises a load control device for controlling an electrical load receiving power from an AC power source, and a controller adapted to be coupled in series between the source and the load control device. The load control system may be installed without requiring any additional wires to be run, and is easily configured without the need for a computer or an advanced commissioning procedure. The load control device receives both power and communication over two wires, and the controller generates a phase-control voltage that has at least one timing edge in each half-cycle, and transmits digital messages by modulating a timing edge of the phase-control voltage relative to a reference edge. The controller may be operable to receive inputs from a plurality of different input devices, and the load control device may be operable to control a plurality of different loads.

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.

A renewable energy resource management system manages a delivery of a power requirement from a multi-resource offshore renewable energy installation to an intelligent power distribution network. The installation includes multiple renewable energy resource components and is capable of variably and independently generating power from each to microgrids comprising the intelligent power distribution network so that the entire power requirement is satisfied from renewable energy resources. An electricity grid infrastructure is also disclosed in which power production is balanced with power consumption so that power storage requirements are minimized.

An apparatus, system, and method are disclosed to manage the generation and use of hybrid electric power. A monitoring module receives signals from one or more sensors. The signals comprise power level information of an electric energy storage device, power level information of one or more energy converters, and power level information of an electric load. A determination module compares the signals to determine whether electric power from the energy converters satisfies the electric load. A regulation module adjusts the electric power from the energy converters in response to a determination by the determination module that the electric power from the energy converters does not satisfy an electric load threshold.

A photovoltaic module-mounted AC inverter circuit uses one or more integrated circuits, several power transistors configured as switches, several solid-dielectric capacitors for filtering and energy storage, several inductors for power conversion and ancillary components to support the above elements in operation. The integrated circuit includes all monitoring, control and communications circuitry needed to operate the inverter. The integrated circuit controls the activity of pulse-width modulated power handling transistors in both an input boost converter and a single-phase or multi-phase output buck converter. The integrated circuit also monitors all power processing voltages and currents of the inverter and can take appropriate action to limit power dissipation in the inverter, maximize the available power from the associated PV module and shut down the inverter output if the grid conditions so warrant. The integrated circuit implements power line communications by monitoring the AC wiring for signals and generating communications signals via the same pulse-width modulation system used to generate the AC power. Communications is used to report inverter and PV module status information, local identification code and to allow for remote control of inverter operation.

A system master unit is connected to a 24V AC power source. One or more slave units is connected to the master unit by a power/communication line. Bulk capacitance in the master and slave units stores power during a power source positive half cycle. When the source voltage is higher than the bulk capacitance voltages, power is delivered to the loads, during which time communication cannot take place over the power/communication line. During the power source negative half cycle, the power/communication line is disconnected from the AC power source and is then used for communication between the master and slave units. System power is delivered from the energy stored in the bulk capacitance.

The power flow model of the multiterminal voltage-source converter-based high voltage DC (M-VSC-HVDC) transmission system for large-scale power systems is studied. The mathematical model is derived using the d-q axis decomposition of HVDC's control parameter. The developed model can be applied to all existing shunt voltage-source converter (VSC) based controllers, including Static Synchronous Compensator (STATCOM), point-to-point HVDC system, back-to-back HVDC system and multiterminal HVDC system. A unified procedure is developed for incorporating the proposed model into the conventional Newton-Raphson power flow solver. The IEEE 300-bus test system embedded with multiple HVDC transmission systems under different configurations are investigated. Simulation results reveal that the proposed model is effective and accuracy in meeting various control objectives.

A power conversion device connected with a three-phase power system through a transformer, including unit converters cascade-connected so that reactors are unnecessary, and volume and weight are reduced. The secondary winding of the transformer is an open winding having six terminals. A first converter group, includes a circuit which has three converter arms, which are star-connected, connected to three of the terminals of the secondary winding. A second converter group, having three different converter arms which are star-connected, is connected to three other terminals of the secondary winding. A neutral point (the point where the star connection is made) of the first converter group, and a neutral point of the second converter group are made to be the output terminals of the power conversion device.

A power line modem interface includes a modem that modulates an RF signal with digital data and demodulates an RF signal to recover digital data. A filter is connected to the modem and to a DC power line that supplies power to a local power supply. The filter couples the RF signals from the modem to the DC power line and filters the RF signals out of the local power supply. The filter includes: a first inductance connected to a hot side of the DC power line; a second inductance connected in series with the first inductance and connected to the local power supply; and a capacitance with a first plate connected between the first inductance and the second inductance and a second plate connected to the modem so that the RF signal is passed between the modem and the DC power line.

A system for supplying additional power to a module having an internal power supply, the system comprising: a module having an associated power supply, the power supply not being designed to accommodate power sharing; at least one load associated with the module, the load receiving power from the power supply; a variable current limited power source connected to the module supplying additional power to the at least one load; and a controller; whereby the variable current limited power supply is responsive to an output of the controller to vary the current limit of the variable current limited power supply.

A tethered airborne electrical power generation system which may utilize a strutted frame structure with airfoils built into the frame to keep wind turbine driven generators which are within the structure airborne. The primary rotors utilize the prevailing wind to generate rotational velocity. Electrical power generated is returned to ground using a tether that is also adapted to fasten the flying system to the ground. The flying system is adapted to be able to use electrical energy to provide power to the primary turbines which are used as motors to raise the system from the ground, or mounting support, into the air. The system may then be raised into a prevailing wind and use airfoils in the system to provide lift while the system is tethered to the ground. The motors may then resume operation as turbines for electrical power generation. The system may be somewhat planar in that many turbines may have their rotors substantially in one or more planes or planar regions. The system may also be adapted to be assembled of modular components such that a variety of different numbers of turbines may be flown, yet the system may be substantially constructed from multiple similar members.

A recreational vehicle includes a chassis having a living space, an electrical system for providing electrical power to the living space, an air conditioner for cooling the living space, a heater for heating the living space, and a plurality of appliances within the living space attached to the electrical system. The recreational vehicle also includes an engine for moving the recreational vehicle, a motor generator for supplying power to the recreational vehicle, a connector for connecting the electrical system of the recreational vehicle to an external power source, and a local area network system electrically connected to the air conditioner, the heater, the plurality of appliances, and the motor generator. The local area network manages the power provided to the to the electrical appliances. A display positioned within the living space shows data related to the air conditioner, the heater, the plurality of appliances, the motor generator and the engine.

A motor drive circuit comprises positive and negative input terminals for connection of the motor circuit to a DC supply, a DC link filter connected between the input terminals: an electric motor having at least two phases, a plurality of motor drive sub-circuits, each connected to a respective phase of the electric motor and which each control the flow of current into or out of the respective phase of the motor that has been drawn from the supply through the DC link filter, and a switching means provided in the electrical path between the DC link filter and the electric motor drive sub-circuits, the switching means being movable between a closed position in which it connects the DC link filter to the motor drive sub-circuits, and an open position which isolates the DC link filter from the motor drive sub-circuits.

A plurality of end-user locations are served by a commercial utility grid. More than one and less than all of the end-user locations are themselves interconnected by a feeder, the feeder not metallically connected to the utility grid. The end-user locations each have a local AC bus that is not metallically connected to the utility grid or to the feeder, but that is linked by a coupler to both the utility grid and to the feeder. None of the local AC buses or the feeder is required to have the same phase or frequency as the utility grid. Locally generated electric power may be passed by means of the feeder to other end-user locations that are on the feeder. Each local AC bus has two or more inverters powering the bus.

The present invention provides a system and method for operating a power line communications system for communicating via an underground residential distribution power system. One embodiment of the present invention includes an aggregation point, which may be co-located with a point of presence, communicatively coupled to one or distribution points. The distribution points are communicatively coupled to one or more medium voltage interface devices. The medium voltage interface devices are communicatively coupled to one or more power line bridges via URD medium voltage power lines. The power line bridges may be co-located with a URD distribution transformer and provide communications to the user devices communicatively coupled to the LV power lines of the distribution transformer.

Provided are a power storage apparatus and a method of controlling the power storage apparatus. The power storage apparatus stores power supplied from a power generation system or a power grid. The power storage apparatus supplies stored power to a load during an electric failure, and supplies stored power to the power grid. The power storage apparatus includes at least one battery cell, a battery management unit coupled to the battery cell, a bi-directional converter coupled to the battery management unit, a bi-directional inverter coupled between the bi-directional converter and the power grid, and a central controller controlling the operations of the bi-directional converter, the bi-directional inverter, and the battery management unit. An uninterruptible power supply (UPS) function may be performed to stabilize the power storage system including the power storage apparatus.

An improved power converter that produces reduced-levels of common-mode voltages, or even entirely eliminates such voltages, is disclosed herein, along with a method of reducing common-mode voltages. In at least some embodiments, the improved power converter is equipped with common-mode filter inductors and a link coupling input and output ports of the power converter with one another to communicate a ground point associated with the input ports of the converter (and the source) to the load. Further, in at least some embodiments, the method includes providing common mode filter inductors as part of the converter, where the inductors are connected at least indirectly to at least one of a rectifier and an inverter of the converter, and communicating a grounded neutral from input ports of the converter to output ports of the converter by way of at least one additional linkage.

Power conversion systems and methods are presented for damping common mode resonance, in which inverter or rectifier switching control signals are selectively modified according to a damping resistance current value computed using a predetermined virtual damping resistance value in parallel with an output or input capacitor and a measured output or input voltage value to mitigate or reduce common mode resonance in the converter.

The invention discloses a bipolar direct current power transmission system with a direct current failure self-elimination capacity. The bipolar direct current power transmission system comprises two current converters, wherein the positive end and the negative end of the first current converter are connected with the positive end and the negative end of the second current converter through two direct current power transmission lines respectively; each current converter consists of a positive electrode current conversion unit and a negative electrode current conversion unit which are connected in series with each other; and joints of the positive electrode current conversion units and the negative electrode current conversion units are grounded. By adopting a bipolar structure, a failed pole is generally required to be closed during direct current failure, so that a perfect pole is not influenced; and therefore, the reliability of the system is improved. A technology that the middle part is led out and grounded is adopted, so that stage construction and storage increase and extension of the system are facilitated; a single pole is put into operation, and then two poles are put into operation, so that the investment benefit can be developed early; furthermore, a grounding branch supplies a current backflow channel to the system under a single-pole loop running mode; and the current of the grounding branch is extremely low during balance running.

A HVDC power grid including a multiplicity of voltage sourced converters arranged in a symmetrical monopole transmission configuration to transmit DC power over a DC power grid of transmission lines connected between the voltage sourced converters, and circuitry implemented for sensing and identifying a fault occurred on a section of a DC transmission line. In response to the sensing, the current on the faulted DC transmission line is controllably drawn down to a target current level, e.g., 50 amp, which will accommodate clearing of the faulted transmission line section by allowing switches located at each end of the faulted transmission line section to be able to open against such level of current without triggering an non-extinguishable or sustained arc across one of the switches. At least one of the switches is capable of opening when the current is reduced to the drawn down level to isolate the transmission line.

A converter circuit for converting an output voltage from an AC power supply is provided with a rectifier circuit for rectifying the output voltage of the AC power supply; first and second capacitors connected in series, for smoothing the output of the rectifier circuit; and a switch circuit for switching the connections between the respective capacitors and the AC power supply so that the output voltage of the AC power supply is applied to each of the respective capacitors at a cycle shorter than the cycle of the AC power supply.

The drive for an a.c. induction motor features a rectifier for converting alternating current into direct current and a current source inverter for converting direct current into alternating current supplied to a motor. A d.c. link choke interconnects the rectifier and the inverter. The inverter includes a first control loop which provides a desired or command d.c. link choke current to a second control loop responsible for the rectifier. For the purposes of the second control loop the actual d.c. link choke current and an input voltage of the inverter are detected. The difference or error between the desired and actual d.c. choke currents are minimized by a compensator. The output of the compensator is added to the detected inverter input voltage, and the sum is fed to a switching pattern generator which controls the switches in the rectifier. In this manner the feedback of the inverter input voltage is decoupled from the compensator responsible for the d.c. link choke current. This makes the parameters of the second control loop substantially independent of the load, thereby enhancing the ease with which the control loop may be tuned and hence the stability of the drive.

Methods and apparatus for providing uninterruptible power are provided by aspects of the invention. One aspect is more particularly directed to an uninterruptible power supply for providing power to a load. The uninterruptible power supply includes an input to receive input power, an output to provide output power, a plurality of battery modules that provide backup power, a power circuit coupled to the input, coupled to the plurality of battery modules and coupled to the output to provide power derived from at least one of the input power and the backup power to the output, a controller, a return line coupled to the controller and coupled to each of the battery modules, and a fist sense line coupled to the controller and coupled to the plurality of battery modules. The controller and each of the battery modules are configured and arranged such that at least one characteristic of the battery modules is determined by the controller based on signals detected by the controller on the first sense line.

A device and a method for controlling the flow of electric power in a transmission line carrying alternating current, in which a first voltage source converter is connected to the transmission line at a first point and a second voltage source converter is connected to the transmission line at a second point. Further, the first and second voltage source converters have their direct current sides connected to a common capacitor unit. Also included is a by-pass switch connected to the transmission line between the first point and the second point in parallel with the first and second voltage source converters so that the first and second voltage source converters will operate as a back-to-back station when the by-pass switch is open and as two parallel static var compensators when the by-pass switch is closed.

Systems and methods are described herein for managing the operations of a plurality of microgrid modules. A microgrid module includes transformers and/or power converters necessary for modifying the input AC or DC power sources to meet the required characteristics of the output power. The microgrid module further comprises a control software module and a power router software module. The control software module receives data from sensors in the microgrid module and controls the flow of power with controllable elements. The power router software module controls the operation of the power router. The power router can detect changes in demand for power within the microgrid module or from other microgrid modules. The power router can adjust the flow of power between the microgrid modules in response to changes in the supply of power to the microgrid module and changes in the demand for power from the microgrid module.

An apparatus and method for converting a DC input power to a DC output power. The apparatus comprises an energy storage module and a burst mode controller. The burst mode controller causes energy to be stored in the energy storage module during at least one storage period, and further causes the energy to be drawn from the energy storage module during at least one burst period. During the at least one burst period, the DC output power is greater than the DC input power. Additionally, the burst mode controller employs a maximum power point tracking (MPPT) technique for operating a device providing the DC input power proximate a maximum power point (MPP).

A load control system comprises a plurality of control devices, each coupled to one of a plurality of device communication links. The device communication links are each coupled to a one of a plurality of link power supplies, which provides power for the control devices on the device communication links. The link power supplies are coupled together via a repeater communication link and operate as repeater devices to retransmit digital messages received from the device communication link onto the repeater communication link, and vice versa. The retransmitted digital messages are substantially the same as the received digital messages. No control devices are coupled to the repeater communication link, such that no control devices draw current through the repeater communication link. A maximum of only two or three link power supplies are coupled between any two control devices of the load control system.

Methods and apparatus for providing uninterruptible power are provided by aspects of the invention. One aspect is more particularly directed to an uninterruptible power supply for providing power to a load. The uninterruptible power supply includes a first input to receive input power from an input power source, an output to provide output power, a bypass input to receive bypass power from a bypass power source, wherein the bypass input is selectively coupled to the output to provide output power from the bypass power source, an input power circuit coupled to the first input and having a DC output that provides DC power having a first DC voltage level, a back-up power source coupled to the input power circuit to provide DC power at the DC output in a back-up mode of operation, and an inverter circuit having an output coupled to the DC output of the input power circuit and having an output coupled to the output of the uninterruptible power supply to provide the output power derived from at least one of the input power source and the back-up power source. The uninterruptible power supply is constructed and arranged in a bypass mode of operation to control the inverter circuit to convert AC power from the bypass power source at the output of the inverter circuit to DC power at the input of the inverter circuit.

A circuit which extends the operational life of a main energy source coupled to a load, said circuit comprising a power generator having a heat source and a cooler thermally coupled to a thermoelectric generator (TEG) for converting thermal energy into electrical energy; and a first capacitor coupled to the TEG for receiving and storing the electrical energy from the TEG. The circuit further comprising at least one switching element coupled between the first capacitor and the load, a converter coupled between the capacitor and the at least one switching element for generating a regulated output, and a controller for activating the at least one switching element when the charge stored on the first capacitor reaches a predetermined level, thereby delivering power from the first capacitor to the load, via the converter, and reducing the amount of power drawn from the main energy source, thereby extending the operational life of the main energy source.