4327 results about "Tidal current" patented technology

A system, method and computer program product for processing utility data of a power grid is provided. In one embodiment, the system includes a datamart comprised of a plurality of physical databases storing utility data, a plurality of applications comprising an automated meter application configured to process power usage data from a plurality of automated meters, a power outage application configured to identify a location of a power outage, and a power restoration application configured to identify a location of a power restoration. The system may include an analysis engine comprising a plurality of analysis objects with each analysis object configured to process data to provide a specific analysis, wherein said analysis engine is accessible via one or more of the plurality of applications, and the system may include a report module configured to receive an output from the analysis engine and to output a report. The plurality of applications may also include a fault analysis application, a transformer analysis application, a theft detection application, a power flow application, a substation automation application, a load shed application and others.

Embodiments of the present invention provide power flow analysis and may process electrical power distribution system data in real time to calculate load, current, voltage, losses, fault current and other data. The power flow analysis system may include a detailed data model of the electrical power distribution system, and may accept a variety of real time measurement inputs to support its modeling calculations. The power flow analysis system may calculate data of each of the three distribution system power phases independently and include a distribution state estimation module which allows it to incorporate a variety of real time measurements with varying degrees of accuracy, reliability and latency.

An apparatus is disclosed for a turbine for generating electrical power from water or air flow comprising at least one rotor disk having a plurality of hydrofoil blades, a guide vanes, a cylindrical housing, and a generator means. A rim generator comprising a magnet race rotor rim and fixed stator coils in the housing is used. The apparatus is fitted with a screen to stop the ingress of debris and marine life, and a skirt augmenter device to reduce the Betz effect. The apparatus is preferably for sub-sea deployment and driven by tidal currents, but may be powered by river current or wave driven air or by wind. The apparatus may be deployed on at least one telescoping pole, tethered to the sea-bed and kept buoyant by buoyant concrete in the housing, inserted in a dam, under a barge or in a tidal power array.

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 system and method for monitoring content/link behavior of web pages/web sites over time can be used for, among other things, compiling relevant information, implementing/influencing a search engine, etc. Certain web pages/web sites can be characterized as trendsetters by studying historical adoption behavior of a group within the universe of websites, or by reference to known indicia.

The invention discloses a microgrid system coordination control method which takes a storage battery energy storage system as a main power supply. The conventional inversion products and technology hardly form a microgrid and cannot meet the requirement on stable operation of the microgrid system. The storage battery energy storage system in the microgrid is taken as a main power supply when the microgrid independently works, the microgrid frequency and voltage are kept constant, and a distributed power supply controls the power along with the microgrid voltage and a phase angle; and a microgrid control system controls a bidirectional inverter for energy storage to effectively switch between a parallel control mode and an independent operation mode according to the state of an external power grid. The power supply in the microgrid has the advantages of high robustness, high speed, and capacities of realizing bidirectional flow of electric energy and flexible current control and meeting the requirement on stable operation of the microgrid system.

A dynamic stochastic optimal power flow (DSOPF) control system is described for performing multi-objective optimal control capability in complex electrical power systems. The DSOPF system and method replaces the traditional adaptive critic designs (ACDs) and secondary voltage control, and provides a coordinated AC power flow control solution to the smart grid operation in an environment with high short-term uncertainty and variability. The DSOPF system and method is used to provide nonlinear optimal control, where the control objective is explicitly formulated to incorporate power system economy, stability and security considerations. The system and method dynamically drives a power system to its optimal operating point by continuously adjusting the steady-state set points sent by a traditional optimal power flow algorithm.

Smooth, preferably variable-sweep fluid collection device surfaces disposed into opposition with wind, river, surf, ocean or tidal currents generate enhanced velocity fluid flows at length driven into onboard work-extracting disc turbines at advantageous angles of attack. Keyed to shafts turning freely through optionally extendable volutes, disc turbines comprising a dense population of smooth, axially fixed or adjustably spaced discs conducting preferably laminar flow between adjacent elements develop significant torque through boundary layer adhesion and viscous shear-stress between fluid layers. Exhaust of disc turbine throughput into divergent channels drafting into external currents of initially higher than ambient velocity and lower pressure may reduce turbine discharge backpressure, rapidly clear system throughput, and allow normally disadvantageous drag to be utilized to develop greater work generation. Gainfully turning with, instead of at odds to natural or anthropogenic currents provided, disc turbines utilized as disclosed may provide unprecedented renewable energy from fluids in motion.

The present invention relates to a power system and provides a method for considering the network security constraints of in the operation of economic dispatch of power systems, which comprises the power flow constraint of branches, the static voltage stability constraint and the transient stability constraint, and provides an effective way for coordinating contradiction between the economy and security of power system operation. The security region based security-constrained economic dispatching method comprises the following steps: step 1, calculating the coefficients for the active power static security region, the cut-set voltage stability region and the dynamic security region respectively; step 2: building the models for security region based security-constrained economic dispatch; step 3: solving the unit on/off state optimal sub-problem through Social Evolutionary Programming; step 4: calculating the generation cost, the static voltage stability margin and the transient stability margin in the dispatching period; step 5: obtaining a feasible economic dispatching scheme, otherwise, return to step 3. The invention is mainly applied in load dispatching optimization.

The invention relates to an assistance determination system of a distribution network programming proposal in a electricity technical field, which includes a data input and output module, a power-supply reliability index generation module, a power-supply capacity index generation module, a power-supply quality index generation module, a short-circuit electric-current level index generation module, a projected economy index generation module, an integrated index generation module, a module for analyzing preconceived accident and displaying an analysis report on the preconceived accident consequence and an inquiry module for an calculation result on the assessment index of the distribution network. The data input and output module is used for inputting the data of the distribution network proposal into each index generation module, and outputting the assessment index calculated by each index generation module. Each index is calculated by each index generation module through calling a topology analysis and a power flow calculation, and the analysis reporting module and the inquiry module carry out an analysis and a report to each module respectively. The invention finds out existing problems and weak steps of the projected proposal quickly and accurately, and provides scientific basis for a revise and an execution of the projected proposal.

The invention relates to an emergency protection circuit device capable of completing automatic switching when an AC-DC power grid is in an abnormal state, and in particular relates to an intelligent warning and control method dedicated for ensuring safety and stability of the power grid. The method comprises the steps that: an intelligent control master station acquires real-time data of the power grid through an EMS (energy management system), and an intelligent control substation in each zone real-timely monitors the bus voltage of the zone, power-receiving channel overload, main transformer overload in the zone and voltage instability of the power grid in the zone, and starts the power grid safety and stability control operation; the acquired real-time data of the power grid is integrated with the information uploaded by each substation to real-timely form tide section data of the power grid, and the safety and stability of the power grid are evaluated online; and safety and stability early-warning information of the power grid is provided by using the real-time operation data of the power grid to realize safe and stable control of the power grid and to realize the function of the second line of defense of the power system. The method provided by the invention can ensure safe and stable operation of the power grid by regulating a stability control device according to the running condition of the power grid.

The invention provides an operation management method of an electric power system cloud simulation platform. The electric power system cloud simulation platform comprises a cloud simulation resource management system and a cloud simulation application supporting system. The method comprises the following steps that the cloud simulation resource management system is constructed; the cloud simulation application supporting system is constructed; the safety of the electric power system cloud simulation platform is determined; operation management of the electric power system cloud simulation platform is carried out. Cloud simulation analytical calculation application is achieved, multiple users can carry out currents, transient stability, small interference, short-circuit currents and other simulation calculation functions on one or more sets of data according to the permission in the mode of facing network services, and the limitation that services and data of standalone version software cannot be shared in large-scale interconnected power grid analytical calculation is eliminated.

The invention discloses a planning method and system for optimizing a micro-grid containing distributed power sources and stored energy, wherein the planning method and system are based on an intelligent optimization algorithm. The planning method is used for optimizing the micro-grid containing the distributed power sources and the stored energy, and comprises the steps that basic data are provided for a planning and design scheme, and modeling and load flow calculation are performed on an area to be planned; a micro-grid wiring mode suitable for the area to be planned is determined; site locations, to be chosen, of the multi-type distributed power sources are determined; a site distribution and capacity determining model is established, and a grid frame of the micro-grid containing the distributed power sources and the stored energy is planned and designed; a joint planning scheme and a joint planning module under a decided investment subject are formed; the joint planning scheme is output and evaluated. According to the planning method and system for optimizing the micro-grid containing the distributed power sources and the stored energy, on the basis of basic characteristic study of the distributed power sources and the micro-grid, planning for optimizing the micro-grid containing the photovoltaic power sources is systematically studied, the positions, capacities and the grid frame structures of all kinds of distributed power sources in the micro-grid in the specified planning area are reasonably allocated, and the micro-grid optimization planning scheme which is complete, effective and high in integrity, and is closely integrated with engineering practice is established.

Neural Network Loadflow (NNL) computation method is invented involving input vector composed of net nodal injection of real and reactive powers and diagonal elements of conductance and susceptance matrices multiplied by the squared voltage magnitude components of the flat-start normally used as initial solution estimate guess for loadflow solution by conventional NRL or SSDL methods. Training, and testing/validating input-output data sets are generated by applying uniform and non-uniform scaling factors applied to base case loads at PQ-nodes, resistance and reactance of transmission line branches. These scale factors are increased until loadflow solution by conventional methods such as Newton-Raphson Loadflow and Super Super Decoupled Loadflow methods diverge. Divergence of loadflow methods are due to node voltage, node angle, and numerical instabilities. Voltage magnitude and phase angle values in the solution before divergence are respective stability limits and voltage magnitude and phase angle values in loadflow solution provide direct measure to the respective stability margins. Also Suresh's diakoptiks based feature selection technique is presented for ANNs calculating one node variable with one neuron each in their output layers.

A power flow controller responsive to power circulation demand for optimizing power transfer is disclosed. When a power flow controller operates at its rated capacity, it can no longer regulate from-bus voltage set-points, line power flow set-points, or both. In such cases, the power flow controller switches to power circulation set-point control without exceeding the rated capacities of the voltage-sourced converters in the power flow controller. Power-voltage (PV) curves associated with voltage stability analysis for maximizing power transfer can be generated and stored for use with a power flow controller operating in automatic power flow control mode.

A method for calculating power flow solution of a power transmission network with unified power flow controllers is adapted to calculate the power flow on a large-scale power transmission network. The unified power flow controller has a series transformer, a series converter, a direct current coupling capacitor, a shunt converter, and a series transformer. The shunt transformer is connected electrically to a sending-end bus. The series transformer is connected electrically to the sending-end bus and a receiving-end bus. The unified power flow controller is represented by equivalent active and reactive loads on the sending-end and receiving-end buses of the power transmission network.

A floating, semi-submerged, tethered device that supports a horizontal axis turbine and power generation equipment for extracting kinetic energy from a tidal stream or ocean current. A submerged body (1) is supported by surface piercing struts (2) of small water plane area (FIG. 6). The device is tethered to the seabed by a spread of mooring lines (12) that are deployed both into and away from the direction of the tidal current. A horizontal axis turbine (4) harnesses energy from the water flow and drives a generator housed within the body. A horizontal strut hydrofoil (24) corrects the trim of the device when subject to varying loads from the mooring system and can also be used to dampen pitch motion. Rudder flaps in the struts (25) can be used to counteract roll motion. Power is exported from the device to the seabed by an umbilical (17). A thrusters (22) can be used to constrain the rotation of the device about its mooring system to prevent excessive twist building up between the mooring lines and the power export umbilical.

A system and method for monitoring and managing electrical power transmission and distribution networks through use of a deterministic, non-iterative method using an holomorphic embedding and algebraic approximants for determining the real-time load flow in a power generating system having an electrical grid. Such method may be employed for real-time or off-line applications for electric power systems reliability assessment, and is capable of determining whether or not a physical solution to the load flow problem exists, or if the system is in a state of voltage collapse.

The invention discloses a rapid prediction method for drifting path and diffusion of marine spilled oil, comprising the following steps of: creating a weather field database; calculating and predicting a wind field of a sea area related to the spilled oil by an atmosphere prediction model; calculating a wave field through a sea wave model, providing open boundary conditions of tides and circulations based on harmonic constants of 8 partial tides provided by a NAO99 global tide model, and taking the wave field as a forcing field to calculate out a three-dimensional current field comprising tidal currents and wind currents through a ocean dynamics model; based on an oil database and the monitored condition of the spilled oil, calculating out the drifting path and the diffusion result of thespilled oil through a spilled oil model comprising a spilled oil expansion and drifting track prediction model and a weathering model; and directly showing the prediction result through a visualization technology to provide scientific evidences for related decisions, such as emergency treatment on marine oil spill pollution, and the like.

The invention relates to a method for analyzing the risk of closed loop operation in a power system, comprising the following steps: (1) acquiring an online power grid model and a data section; (2) setting a closed loop operation point; (3) automatically carrying out topology search of closed loop path in the whole network; (4) calculating the impedance of a closed loop interface; (5) calculating closed loop electric current on line; (6) analyzing and calculating power grid state after a loop is closed; (7) prompting the risk of the closed loop operation: a prompting message indicating whether the closed loop is reasonable or not is provided to the power system for dispatching and to the operating staff for reference based on the result calculated by the closed loop electric current, the closed loop flow and the power grid flow after the loop is closed and the topology search result of the closed loop path. Based on the invention, the closed-loop risk can be accurately analyzed so as to prompt the operating staff to avoid the false operations and ensure the operation safety.

The invention provides a failure propagation method for evaluating the reliability of a distribution network, and relates to a method for evaluating the reliability of a medium voltage distribution network which runs radially. The method uses a computer to perform the enumeration calculation on a failure event of each element in the distribution network by a state enumeration method through a program, and performs the power flow calculation of the distribution network and the reliability index calculation of the distribution network for output. In the method, a reliability index of the distribution network can be formed at one time, the reliability of distribution networks with a simple structure and a complex structure with a subfeeder can be calculated, the influence of a breaker, branchline protection, an isolation switch, a standby power supply, a standby transformer and the like in the distribution network is taken into consideration, and a model has good commonality, high calculation speed and strong engineering practicability, and is easy to popularize and apply. The method can be widely applied to the reliability evaluation of the distribution network, and is particularlysuitable for the reliability evaluation of the distribution network between 3 and 20kV.

The invention relates to a method for evaluating the new energy development potential of regional power grids based on power generation absorption. New energy power characteristics are described from the level of new energy output power parameters, and power grid structure constraints are described from the level of power grid load flow calculation parameters. Based on a sequential production simulation method, by establishing a multi-period load flow optimization evaluation model and adopting matlab software for programming simulation calculation, a corresponding new energy receptivity evaluation model is established with the power generation of new energy units as the objective function and the new energy wind curtailment/light curtailment rate as the constraint. The new energy development degree of the regional power grids is comprehensively measured, visual development potential measurement indexes are obtained finally, and the new energy receptivity trend of the regional power grids is analyzed in a drawing mode. The power generation of the power grids by renewable energy absorption is simply and visually calculated, and reasons for the insufficient new energy receptivity of the power grids are analyzed. The economy and safety of power grid operation are analyzed based on various operation scenes, and the new energy receptivity of the power grids under various scenes is studied.

The invention discloses a reactive optimization method for a distribution network. The method comprises the following steps: firstly, building an actual operation model of the distribution network, then conducting load flow calculation, analyzing the voltage quality, applying a reactive optimization administrative tool to formulate a reactive optimization scheme, adopting the simulated analysis method to examine and regulate the appointed optimization scheme, and finally achieving reactive optimization of the distribution network according to the regulated reactive optimization scheme. The invention also discloses a reactive voltage optimization system for the distribution network, which corresponds to the method. The method and the system solve the difficult reactive optimization problem of the distribution network and provide theoretical foundation and decision support for planning, operation, reconstruction and management of the whole distribution network.

The invention relates to an optimal power flow optimization method of distributed power supplies. The optimal power flow optimization method of the distributed power supplies includes the following steps: A, variable in a distribution network is initialized; B, load flow calculation is carried out on the distribution network; C, lines are judged to be overloaded or not, and active output force and reactive output force of an engine and the distributed power supplies are judged to overstep the boundary or not; D, if constraint equations are all met, a step E is continued, otherwise a step F is continued; E, an objective function is judged to be the minimum or not, if the objective function is the minimum, a step J is continued, otherwise a step F is continued; F, net loss correlation coefficients are corrected; G, a Jacobean matrix and a Hessian matrix are calculated; H, a problem of sequential quadratic programming is formed and the search direction and a step size are solved; I, output force at the position of a balancing node bus and output force of each distributed power supply are corrected, and the step B is jumped to; and J, an optimal power flow result is output. The optimal power flow optimization method of the distributed power supplies provides basis of access capacity calculation for determining the distributed power supplies to be connected in a power distribution network, is simple in calculation and low in complexity, and can rapidly calculate the output force of the distributed power supplies.

The invention discloses a distributed power source contained power system multi-target reactive-power optimization method in the field of power system reactive-power optimization. The technical scheme includes: 1, deducing a model of a wind-driven generator in power flow calculation; 2, initializing power grid parameters and grid-connected parameters of a distributed power source; 3, constructing an individual vector formed by system reactive-power optimization control variables, and initializing species; 4, performing the power flow calculation according to the initialized species and grid parameters after grid-connection of the distributed power source, and calculating objective function values; 5, performing multi-target optimization by utilizing the harmony search hybrid algorithm based on artificial bee colony; and 6, finishing the optimization process and outputting optimized results. The distributed power source contained power system multi-target reactive-power optimization method is a hybrid optimization algorithm ABS-HS which integrates the advantages of global search of the artificial bee colony (ABC) algorithm with local search of the existing harmony search (HS) algorithm, so that efficiency and robustness of the algorithm are improved.