Patent application number | Description | Published |
20090079267 | CONVERTER CONTROL UNIT - The disclosure relates to a converter control unit or power system stabilizing unit for counteracting oscillations in electric power systems that is equipped and employed to provide and processes information for system-wide monitoring, protection, control and metering. It comprises means for synchronized (e.g. via GPS or another absolute/global time reference) sampling of voltages and/or currents, means for down-sampling in order to decrease the number of samples, and means for calculating phasors, i.e. time stamped amplitude and phase angle of the voltages and/or currents. | 03-26-2009 |
20100094477 | DETERMINATION AND USE OF POWER SYSTEM SENSITIVITIES - The present disclosure relates to power system sensitivities as computed from power flow parameters and control parameters of a Power Flow Control Device (PFC). To this end, control parameter variations are applied to or generated by a PFC, and comprise variations in a control input u, a control effort e (injected series voltage, inserted series reactance), or a control effect q (power flow, active power transfer, phase-shift, current). A power flow response measuring unit measures a variation of a power flow response such as current, active or apparent power, in a way sufficiently synchronized with the control parameter variation to allow establishing an unambiguous causal relationship or correspondence in the form of a power system sensitivity. The latter may be on-line adapted to continuously reflect an updated aspect of the power system behaviour, and thus enable an improved, fast and reliable power flow control in power systems comprising a meshed power network with two parallel flow paths or corridors connecting two areas or sub-systems. | 04-15-2010 |
20100127664 | METHOD FOR OPERATING AN ENERGY STORAGE SYSTEM - The present disclosure is concerned with operation of an energy storage system (ESS) connectable to an electric power system. The charging-discharging schedule of the ESS can be determined through application of a time-dependent forecast of ESS and power system states based on historical data. Exemplary embodiments can include ESSs which have been historically activated with a certain periodicity, for example, for power system load leveling, frequency regulation, arbitrage, peak load shaving and/or integration of renewable power generation. | 05-27-2010 |
20100332211 | PROGRAMMABLE AND RECONFIGURABLE HARDWARE FOR REAL POWER SYSTEM EMULATION - An apparatus is provided for emulation of a power system. The apparatus includes a plurality of programmable elements which are selectively connectable to one another. Each programmable element includes at least two elements selected from the group consisting of a generator element, a line element and a load element. A programmable switch element is operable to selectively connect the at least two elements of each programmable element to one another, and to selectively connect the programmable element to one or more other programmable elements. A system, which incorporates the apparatus, is also provided for emulating a power system incorporating such apparatus. | 12-30-2010 |
20110282507 | METHOD AND APPARATUS FOR ADAPTING AT LEAST ONE SET OF PARAMETERS OF AN INTELLIGENT ELECTRONIC DEVICE - The disclosure concerns a method and an apparatus for adapting at least one set of parameters to at least one Intelligent Electronic Device (IED) of an electrical power network having a plurality of switching devices (CB). The method includes: a) reading the current network status of the electrical power network, wherein the network status includes the status of the plurality of switching devices; b) simulating at least one network fault in the electrical power network; c) deducing at least one new set of parameters for the at least one IED using a simulated fault current induced by the at least one simulated network fault under consideration of the present network status and the network topology of the electrical power network; and d) setting the at least one set of parameters in at least one of the at least one IED. The apparatus a) reads the current network status of the electrical power network, b) selects the at least one set of parameters for the at least one Intelligent Electronic Device out of a plurality of sets of parameters depending of the current network status; and c) sets the at least one set of parameters in the at least one IED. | 11-17-2011 |
20120239215 | METHOD AND APPARATUS FOR DETECTING ISLANDING CONDITIONS OF DISTRIBUTED GENERATOR - A method and apparatus are provided for detecting islanding conditions for distributed generators connected to a grid. The method includes estimating a grid impedance, and inducing, on the basis of the estimated grid impedance, a variation on a value of a first electrical quantity of the grid. The method also includes monitoring a grid response to the variations, and determining islanding conditions on the basis of the monitored response. | 09-20-2012 |
20120248873 | ENERGY STORAGE SYSTEMS - A method for controlling an energy storage system for connection to a power system, and such an energy storage system are provided. The method makes use of a model based predictive controller to optimize the charging/discharging rates of energy storage elements in a hybrid energy storage system. The method includes determining respective desired charging/discharging rates for the energy storage elements in dependence upon state of charge predictions from respective models of the storage elements, using model predictive control, and adjusting respective charging/discharging rates of the storage elements in accordance with the determined rates. The energy system includes a controller configured to control respective charging/discharging rates of the energy storage elements in accordance with the method. | 10-04-2012 |
20130114302 | METHOD AND APPARATUS FOR DETECTING ISLANDING CONDITIONS OF A DISTRIBUTED GRID - An exemplary method and apparatus for detecting islanding conditions of a distributed grid are disclosed, wherein transfer of power through a power electrical unit is controlled on the basis of a control reference. The apparatus includes a first stage and a second stage performing a respective portion of the method. The first stage injects a reactive component to the control reference, and, for at least one electrical quantity of the grid, determines a change in the quantity induced by the injected component, and determines, on the basis of the change in the electrical quantity, whether to move to the second stage of the method. The second stage, for at least one electrical quantity of the grid, determines a value of the electrical quantity, forms a positive feedback term using at the determined value adding a positive feedback term to the control reference, determines a change in an electrical quantity induced by the feedback term, and determines islanding condition on the basis of the change in the quantity induced by the feedback term. | 05-09-2013 |
20130187454 | DETECTING ISLANDING CONDITIONS IN POWER NETWORKS - A method is provided for detecting islanding conditions in an electric power network which includes a plurality of sub-networks. The sub-networks include at least one power electrical unit and are separable from each other and a main grid supplying the network by switching devices. The method includes determining topological information of at least one sub-network of interest, detecting islanding conditions in at least one sub-network of interest on the basis of the topological information by using separate detecting devices for each sub-network of interest, and sending, on the basis of the islanding conditions detected by using the detecting devices, a disconnect signal to at least one power electrical unit in at least one sub-network of interest. | 07-25-2013 |
20150039145 | Microgrid Energy Management System and Method for Controlling Operation of a Microgrid - A microgrid includes a plurality of distributed energy resources such as controllable distributed electric generators and electrical energy storage devices. A method of controlling operation of the microgrid includes periodically updating a distributed energy resource schedule for the microgrid that includes on/off status of the controllable distributed electric generators and charging/discharging status and rate of the electrical energy storage devices and which satisfies a first control objective for a defined time window, based at least in part on a renewable energy generation and load forecast for the microgrid. The method further includes periodically determining power set points for the controllable distributed energy resources which satisfy a second control objective for a present time interval within the defined time window, the second control objective being a function of at least the distributed energy resource schedule for the microgrid. | 02-05-2015 |