69 results about "Reverse power flow" patented technology

An inverter energy system supplies power to a site. The inverter energy system comprises a number of solar strings, each solar string including a solar panel(s) as a renewable energy source and an inverter. The inverter energy system is connected to a mains power supply (grid) and to a site load (sub circuits). The forward or reverse power flow into or out of the mains power supply is monitored at a monitoring point at the site. A rate limit is set for power flow into and / or or out of the mains power supply. The supply of power from the inverter energy system is controlled so that the power flow into or out of the mains power supply is within the set rate limit.

A system coordination unit 1 includes a reverse power flow prevention circuit 10. When power output from a fuel cell 6 and / or a secondary cell 7 exceeds power consumed in AC loads and DC loads, the reverse power flow prevention circuit 10 prevents a reverse flow of excess power into a commercial power source 4. The reverse power flow prevention circuit 10 is interposed in an AC main power path 20 between a connection point of a solar cell 5 and the AC main power path 20 and each of a connection point of a fuel cell 6 and the AC main power path 20 and a connection point of a secondary cell 7 and the AC main power path 20. The reverse power flow prevention circuit 10 compares the power output from the fuel cell 6 and / or the secondary cell 7 with the power consumed in the AC loads and the DC loads. Upon determining that the former power is not less than the latter power, the reverse power flow prevention circuit 10 electrically interrupts the AC main power path 20. Consequently, the reverse power flow of the power generated by the fuel cell 6 and / or the secondary cell 7 into the commercial power source 4 is prevented by making use of only one reverse power flow prevention circuit 10. Therefore, in comparison with a case where each distributed power source other than a solar cell 5 is provided with a reverse current flow prevention device, the system can be implemented at a low cost.

An apparatus and method for measuring the source-side line voltage from a source potential transformer (PT) of a regulator during reverse power flow. A reverse power regulation algorithm (“Source Side PT”) is employed during reverse power operation of the tapchanger to energize a contact relay which switches the analog voltage input from the load side to the source side of the regulator. Voltage regulation then operates based on the measured source side voltage instead of the traditional calculation of the source side voltage based upon the load-side voltage and regulator type.

An apparatus for controlling the operation of power conditioners (10) for supplying the generated power to an external power system such as a commercial power system, in which power conditioners (10) are interconnected to an external power system, the power conditioners (10) are interconnected through information exchange means, at least one of the power conditioners (10) monitors the reverse power flow, and the power conditioners (10) exchange the monitor information with information of the other power conditioners (10), thereby equalizing the outputs of all the power conditioners (10). A generator (42) has armature windings (60), and an inverter circuit (13) of the power conditioner (10) provided for each of the armature windings (60) is controlled by cable or radio.

A voltage regulator (10) for regulating a power distribution system voltage during forward or reverse power flow. The voltage regulator (10) accommodates multiple configurations of a tertiary winding (30) and a potential transformer (36) connected across source-side bushings (S / SL) or load-side bushings (L / SL). The invention simulates operation of a potential transformer (36), and the output voltage therefrom, connected across the source-side (S / SL) or load-side bushings (L / SL). The invention also produces a corrected voltage compensating a non-standard turns ratio of the tertiary winding (30). The regulator (10) controls a tap changer (18) to regulate the system voltage according to a digital value representing the voltage across the source-side (S / SL) or load-side bushings (L / SL), comprising a measured voltage, the corrected voltage or the simulated voltage. The digital value is converted to an analog voltage and supplied to external terminals (102) for measuring by a service technician using a voltmeter (104).

A voltage regulator (10) for regulating a power distribution system voltage during forward or reverse power flow. The voltage regulator (10) accommodates multiple configurations of a tertiary winding (30) and a potential transformer (36) connected across source-side bushings (S / SL) or load-side bushings (L / SL). The invention simulates operation of a potential transformer (36), and the output voltage therefrom, connected across the source-side (S / SL) or load-side bushings (L / SL). The invention also produces a corrected voltage compensating a non-standard turns ratio of the tertiary winding (30). The regulator (10) controls a tap changer (18) to regulate the system voltage according to a digital value representing the voltage across the source-side (S / SL) or load-side bushings (L / SL), comprising a measured voltage, the corrected voltage or the simulated voltage. The digital value is converted to an analog voltage and supplied to external terminals (102) for measuring by a service technician using a voltmeter (104).

The invention discloses a solving method for calculating an operational domain of a distributed power supply and microgrid in a power distribution network. The method comprises the steps of obtaining the working site and the operational domain of the power distribution network and the definition of an operation boundary respectively, and obtaining a mathematical model of the operational domain; obtaining DG force exerting constraint and operational domain boundary, system power flow equality constraint and the operational domain boundary, voltage excursion constraint and voltage boundary, reverse power flow constraint and reverse power flow boundary, and feeder line capacity constraint and feeder line capacity boundary; obtaining the operational domain of the distributed power supply and the microgrid in a given power distribution network according to a calculating result. According to the solving method for calculating the operational domain of the distributed power supply and the microgrid in the power distribution network, N-1 simulation is not needed, the working state of each working point in the system obtained through power flow calculation, and whether the working site is at a safe operation state or not is judged; in the power flow calculation, node voltage and trend loss are taken into consideration, and an accurate result is obtained; the force exerting ranges of each DG and microgrid in the power distribution network are given, which makes it convenient for scheduling personnel to conduct adjusting and controlling on a power grid, and thus the method has the advantages of being quick, accurate and practical.

An information handling system having an energy saving power converter that comprises a main converter for supplying power to the information handling system when in active operation, and an auxiliary converter for supplying standby power to the information handling system when in a sleep or shutdown mode of operation. The main converter is designed to supply the maximum amount of power required by the information handling system, and the auxiliary converter is designed to supply only enough power to maintain the information handling system in the sleep or shutdown mode of operation. The main converter goes into a standby or shutdown condition when not supplying power to the information handling system. The auxiliary converter is designed to draw a minimum amount of energy, only enough to maintain the information handling system in the standby or shutdown mode of operation. A voltage or current sensing logic is used to determine when the main converter should be active and when it should be in standby. A capacitor in the power converter stores enough energy so that the information handling system does not experience transients when the main converter goes back and forth between the active and standby conditions. Power blocking diodes may be used to prevent reverse power flow between the main converter and the auxiliary converter. A plurality of converters may be used for minimum standby power and maximum power conversion efficiency.

The invention provides a photovoltaic reverse power controller, which is applied to a solar photovoltaic generating system. At present, the conventional anti-reverse current relay in the market does not have the photovoltaic reverse power control function, can only control reverse power within a certain range and cannot ensure the photovoltaic generating system is a reverse current-free system. The photovoltaic reverse power controller receives information acquired and processed by a reverse power acquisition and monitoring system, intelligently controls main loops of the photovoltaic generating system to perform synchronization power generation or stop the synchronization power generation, and keeps the output power of the photovoltaic generating system automatically matched with the load consumed power to realize the reverse power control function. In the figure, an input port receives the information of the reverse power acquisition and monitoring system, and outputs a control command to a photovoltaic sub system after the information is calculated and processed by a singlechip.

A battery charger for charging a battery with voltage from an input supply and method for using are disclosed. In one embodiment, the battery charger comprises a power path to drive the battery during a pulse charging sequence in a first mode and to reverse power flow from the battery when operating in a boost mode during the pulse charging sequence and an energy storage component coupled to the power path to capture pulse discharge energy during the pulse charging sequence when the circuit stage is operating in the boost mode.

A controller installed at each consumer side comprises: a power generation amount acquisition unit acquiring the amount of electricity that has been generated in a solar cell; a power selling amount acquisition unit acquiring the amount of electricity for sale that has been allowed to flow into an electric power system by reverse power flow, among the electricity generated in the solar cell; and a power selling suppression control unit configured to set a threshold value for the amount of the electricity for sale, as proportional to the amount of the generated electricity acquired by the power generation amount acquisition unit, and configured to suppress the reverse power flow into the electric power system so that the amount of the electricity for sale is set to the threshold value or less.

A management server comprises a transmitter configured to transmit a power instruction message to a facility; and a manager configured to manage at least one of suppression influence information and storage apparatus information, the suppression influence information affecting a suppression of a forward power flow amount from a power grid to the facility or a reverse power flow amount from the facility to the power grid, the storage apparatus information being related to an energy storage apparatus installed in the facility. The transmitter is further configured to transmit the power instruction message to the facility, based on at least one of the suppression influence information and the storage apparatus information.

The invention relates to an isolated bidirectional DC / DC converter and a control method thereof. A resonant inductor of a primary side in a CLLC circuit is adjusted to a secondary side, and an auxiliary unit is arranged in the circuit, so that the converter can realize boost and buck conversion during forward and reverse working; meanwhile, gain characteristic curves under different loads and powers during forward power flow and reverse power flow are analyzed, a control strategy applied to a full working range is provided, the isolation type bidirectional DC / DC converter is combined with the control strategy of the full working range, the requirement for a wide-range voltage output occasion can be met, and the soft switching of the device can be well realized in light load.

A power management apparatus includes a receiver configured to receive measurement information obtained by measuring a power of a facility connected to a power grid; and a transmitter configured to transmit a power control message. The transmitter transmits the power control message based on an output power amount of a distributed power supply provided in the facility, in addition to the measurement information. The measurement information is information indicating a total power flow amount from the power grid to the facility or a total reverse power flow amount from the facility to the power grid. The distributed power supply is a power supply that allows a reverse power flow from the facility to the power grid.

An example method comprises receiving first historical meso-scale numerical weather predictions (NWP) and power flow information for a geographic distribution area, correcting for overfitting of the historical NWP predictions, reducing parameters in the first historical NWP predictions, training first power flow models using the first reduced, corrected historical NWP predictions and the historical power flow information for all or parts of the first geographic distribution area, receiving current NWP predictions for the first geographic distribution area, applying any number of first power flow models to the current NWP predictions to generate any number of power flow predictions, comparing one or more of the any number of power flow predictions to one or more first thresholds to determine significance of reverse power flows, and generating a first report including at least one prediction of the reverse power flow and identifying the first geographic distribution area.

This invention relates in general to a device for isolating, controlling, limiting and supporting the power exported from the renewable energy source to the utility grid. The device comprising: a means for monitoring the direction of flow of power within the renewable energy source; a means for isolating the flow of power from the renewable energy source to the mains power supply; and wherein when a reverse power flow above agreed feed in or at least zero feed in or limited feed in is sensed by the means for monitoring between the renewable energy source to the mains power supply, the monitoring means signals the isolating means to open circuit the system and / or control / limit output of the system.

The present invention, which satisfies FRT requirements and reliably supplies power to a load even when there is a system abnormality, is provided with: a distributed power supply 2 connected to a power line L1 for feeding power from a commercial power system 10 to an important load 30; an opening / closing switch 3 that is on the power line L1 and provided closer to the commercial power system thanthe distributed power supply 2; an impedance element 4 connected in parallel to the opening / closing switch 3; a system abnormality detection unit 5 that detects abnormalities in the commercial powersystem 10; and a switch control unit 6 that opens the opening / closing switch 3 and connects the distributed power supply 2 and the commercial power system 10 via the impedance element 4 when an abnormality in the commercial power system 10 is detected. While the distributed power supply 2 and the commercial power system 10 are connected via the impedance element 4, the distributed power supply 2 continues an operation including reverse power flow. The distributed power supply 2 has a rotary power generation device 23 and an energy storage device 22. The energy storage device 22 has: an energystorage unit 221; a bi-directional power convertor 222 that charges / discharges the energy storage unit 221; and a convertor control unit 223 which controls the bi-directional power convertor 222 and performs an operation simulating the inertia of the rotary power generation device 23.

Provided is an apparatus and method for preventing reverse power flow of an over current relay. When a neutral line current is greater than a phase current, it is determined that a reverse power flow occurs, and thus a protection relay is prevented from malfunctioning. The apparatus for preventing reverse power flow of an over current relay includes: a detecting unit which detects a phase current and a neutral line current; a reverse power flow determining unit which is electrically connected to the detecting unit and compares the phase current and the neutral line current which are detected by the detecting unit to determine whether or not a reverse power flow occurs; a setting unit which is electrically connected to the reverse power flow determining unit and sets an operation time and the number of operation times of a protection relay; and an operation unit which is electrically connected to the setting unit and operates the protection relay in a manner set by the setting unit.