4452results about "Ac networks with different sources same frequency" patented technology

Systems and methods to balance currents among a plurality of photovoltaic units connected in series. In aspect, a management unit is coupled between a photovoltaic energy production unit and a string of energy production units. The management unit has an energy storage element (e.g., a capacitor) connected to the photovoltaic energy production unit. The management unit further has a switch to selectively couple to the energy storage element and the photovoltaic energy production unit to the string. The management unit allows the current in the string to be larger than the current in the photovoltaic energy production unit.

Secondary resonant pickup coils (102) used in loosely coupled inductive power transfer systems, with resonating capacitors (902) have high Q and could support large circulating currents which may destroy components. A current limit or "safety valve" uses an inductor designed to enter saturation at predetermined resonating currents somewhat above normal working levels. Saturation is immediate and passive. The constant-current characteristic of a loosely coupled, controlled pickup means that if the saturable section is shared by coupling flux and by leakage flux, then on saturation the current source is terminated in the saturated inductor, and little detuning from resonance occurs. Alternatively an external saturable inductor (1101, 1102) may be introduced within the resonant circuit (102 and 902), to detune the circuit away from the system frequency. Alternatively DC current may be passed through a winding to increase saturation of a saturable part of a core. As a result, a fail-safe pickup offering a voltage-limited constant-current output is provided.

A large-scale, capacitor-based electrical energy storage and distribution system capable of effectuating load-leveling during periods of peak demand on a utility, and of effectuating a cost savings associated with the purchase of electrical energy. A capacitor or multitude of capacitors may be charged with electrical energy produced by the utility, such as during periods of low demand or low cost, and discharged during periods of high electrical energy consumption or high electrical energy cost. One or more capacitors may be located at a consumer's residence or business. Alternatively, a farm of capacitors may be provided at or near a utility, or at or near a location experiencing high demand. In another embodiment, one or more capacitors may be located in or on a vehicle, such as an automobile, a truck, or a train of a light rail system.

A method and apparatus for aggregating power from multiple sources generates a single direct current regulated voltage. The apparatus comprises a plurality of slave voltage converters and a master pulse width modulator circuit. Providing a plurality of direct current power sources, current is drawn through a plurality of lines connected to the plurality of direct current power sources. An open circuit voltage for each direct current power source is unknown. Each line of the plurality of lines has a line resistance. The line resistance of at least some of the plurality of lines may be unknown. The line resistance of at least some of the plurality of lines is large. The single direct current regulated voltage is generated from the drawn current.

Embodiments of the invention can provide systems, methods, and an apparatus for converting direct current (DC) power to alternating current (AC) power. According to one embodiment, a system for converting DC power to AC power can be provided. The system can include a DC power source electrically coupled to a DC-to-DC converter. The DC power source can be associated with a first ground, and the DC-to-DC converter can be operable to isolate the power provided by the DC power source from the first ground. The DC-to-DC converter can be further operable to condition the DC power and to provide the conditioned DC power to an inverter. The inverter can receive the conditioned DC power and can convert the conditioned DC power to AC power. The AC power can be associated with a second ground and can be provided to at least one load electrically coupled to the inverter.

According to one exemplary embodiment, an efficient and high speed E-mode III-N/Schottky switch includes a silicon transistor coupled with a D-mode III-nitride device, where the silicon transistor causes the D-mode III-nitride device to operate in an enhancement mode. The E-mode III-N/Schottky switch further includes a Schottky diode coupled across the silicon transistor so as to improve efficiency, recovery time, and speed of the E-mode III-N/Schottky switch. An anode of the Schottky diode can be coupled to a source of the silicon transistor and a cathode of the Schottky diode can be coupled to a drain of the silicon transistor. The Schottky diode can be integrated with the silicon transistor. In one embodiment the III-nitride device is a GaN device.

A microgrid is a portion of an electric grid configured for separate management and control as compared with the rest of the grid and having attributes that can be tailored to meet specified needs including the needs of electric power consumers served by the microgrid.

The invention relates to an MAS-based (multi-agent system) multi-microgrid energy management system simulation method. The method is characterized in that a multi-microgrid energy management system is divided into a local management layer, a microgrid management layer and a microgrid coordinated management layer in different levels; various energy management functions of the different layers are used to establish a multi-microgrid energy management system model by different types of agents, and agent communication protocol is designed for coordination and convention of the agents. The agents in different control layers of the local management layer, the microgrid management layer and the coordinated management layer are integrated by a client-server architecture, and accordingly an MAT-based (multi-agent technology-based) multi-microgrid energy management system simulation platform is formed. The method is provided to verify different microgrid control strategies and scheduling plans.

In large PV power plants, grounding of individual PV modules may lead to problems. The present invention overcomes such problems. The basis for the invention is a PV power plant comprising one or more PV generators, each comprising a PV string and an inverter with a DC input and an AC output. The PV string comprises at least one PV module and is electrically connected to the DC input of the inverter. The inverter comprises means for controlling the DC potential at the DC input depending on the DC potential at the AC output. The AC outputs of the inverters are coupled in parallel. The novel feature of the invention is that the PV power plant further comprises an offset voltage source, which controls the DC potential at the AC outputs. Thereby, the DC potential at the DC input will be indirectly controlled, and it is thus possible to ensure that the potentials with respect to ground at the terminals of the PV modules are all non-negative or all non-positive without grounding the PV modules. Ground loops can be avoided, and there is no need for the use of transformer-based inverters.

Management control system for managing an energy supply and storage system for a rig power supply of the type having a power generator coupled to rig loads, the power generator used for powering the rig and for charging the storage system, and the storage system adapted for selectively supplementing rig power, is adapted for controlling the selection of rig function operation, for setting the system to recommended settings for the selected rig function operation, for monitoring rig power usage for the selected rig function operation for distributing excess power to the storage system when the rig power usage falls below a preselected threshold, and for distributing stored power from the storage system when the rig power usage is above a preselected threshold. The recommended setting for the selected rig function may be modified depending upon power usage by setting preselected thresholds.

In order to effectively supply and demand electric power between an electric power supplier and a node or a group of nodes individually having an electric power generator, the present invention provides an electric power supply and demand management system capable of obtaining the difference between the total of electric power supplied from the electric power supplier to the node or group and the total of electric power consumed by the electric power loads of the node or group and capable of transmitting information for increasing/decreasing the amount of electric power supply so that the difference becomes smaller to the electric power supplier.

Systems and methods for supplying power (both active and reactive) at a medium voltage from a DCSTATCOM to an IT load without using a transformer are disclosed. The DCSTATCOM includes an energy storage device, a two-stage DC-DC converter, and a multi-level inverter, each of which are electrically coupled to a common negative bus. The DC-DC converter may include two stages in a bidirectional configuration. One stage of the DC-DC converter uses a flying capacitor topology. The voltages across the capacitors of the flying capacitor topology are balanced and switching losses are minimized by fixed duty cycle operation. The DC-DC converter generates a high DC voltage from a low or high voltage energy storage device such as batteries and/or ultra-capacitors. The multi-level, neutral point, diode-clamped inverter converts the high DC voltage into a medium AC voltage using a space vector pulse width modulation (SVPWM) technique.

The present invention relates to a load management controller for a household electrical installation comprising a pair of electricity supplies, a grid supply and a micro-generator supply, providing electricity to a plurality if sub-circuits. The household electrical installation has means to monitor the amount of electricity being supplied by the micro-generator supply and the amount of electricity being consumed in the household. The load management controller has means to access and use that information to control the supply of electricity to an energy storage sub-circuit to route surplus electricity supplied by the micro-generator to the energy storage sub-circuit. Furthermore, the load management controller can communicate with a remote electricity supplier to control the loads in the household to achieve better grid management and efficiency.

Apparatus and methods for transmitting power over non-adjacent multiple conducting pairs and aggregating power from the conducting pairs to power a remote electronic device. In an embodiment, the apparatus and method comprises a wiring closet which has power supplying capabilities for providing power to a plurality of conducting pairs. A remote termination is adapted to aggregate power provided to and transmitted by two or more non-adjacent conducting pairs. The aggregated power is supplied to a remote electronic device. Preferably, a plurality of power circuits provide power to the conducting pairs. Preferably one or more rectifier circuits aggregate power from the non-adjacent pairs to the remote electronic device.

The present invention provides a simplified method of controlling power among the various sources and loads in a power system. Power generating sources are each connected to a common DC bus through a converter designed to optimize power flow to the DC bus. A DC storage device is connected to the common DC bus through a power regulator designed to maintain a constant voltage on the DC bus. Further, an inverter may be provided to convert the DC voltage to an AC voltage for a customer load or for connection to the utility grid. Each power conversion device is independently controlled to provide a modular and simplified power control system.

The invention relates to a multi-agent optimized coordination control method of an electric network in the technical field of electric networks, which comprises the following steps of: collecting local electric information, transmitting the local electric information to a central agent of a microgrid and issuing a control command by a local electric network to the central agent of the microgrid simultaneously; computing by a grid technology; issuing a new control command by the central agent of the microgrid and transmitting the information to a regulation agent of the local electric network by a network line simultaneously; receiving a dispatching instruction of the central agent of the microgrid by the agent of each element and carrying out logical judgment on a result executing these dispatching commands according to the collected local electric information; and meanwhile, optimizing the electric network within a control range by the regulation agent of the local electric network and controlling a computer to carry out parallel computation by the grid technology. The invention is suitable for carrying out optimal dispatching on a distributed energy resource of an intelligent electric network, can control each power supply by an optimization scheme, also enhances the operational processing time greatly and ensures that the intelligent electric network runs safely, stably and economically.

A method and system for operating a mini-grid including one or more power generation sources and one or more loads independently from a utility grid is provided, where the mini-grid is disconnected from the utility grid in response to a power disruption over the utility grid. A universal interconnect device forms a connection between the mini-grid and the utility grid. In the disconnected state, the mini-grid operates independently from the utility grid, such that the power generation sources of the mini-grid supply the loads. Frequency and voltage regulation are provided by the universal interconnect device through a monitoring function performed by a controller in conjunction with at least an energy storage device, which can absorb or generate power as needed.

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.

A system for filtering and interpreting real-time sensory data from an electrical system is disclosed. The system includes a data acquisition component, a power analytics server and a client terminal. The data acquisition component acquires real-time data output from the electrical system. The power analytics sewer is comprised of a virtual system modeling engine, an analytics engine, and a decision engine. The virtual system modeling engine generates predicted data output for the electrical system. The analytics engine monitors real-lime data output and predicted data output of the electrical system. The decision engine compares the real-time data output against the predicted data output to filter out and interpret indicia of electrical system health and performance. The client terminal is communicatively connected to the power analytics server and configured to display the filtered and interpreted indicia