Abstract:
The present invention is concerned with supervision of a power distribution system (1), in particular visualizing and displaying a system state to an operator. Specifically, the present invention relates to a method of and a system for visualizing or contouring a power distribution system state by displaying to an operator output data values (3) interpolated at output data locations (4) from input data including distributed input data sensor locations in three dimensions and corresponding dynamically updated input data values. The method is comprised of defining triangles (7) in the volume, determining, for each triangle (7), closest input data locations (5) according to a closeness criteria, projecting each triangle (7) onto a visualization plane (11), determining, for an output data location (4) on the visualization plane (11) at least one triangle (7), the projection of which includes the output data location (4), and interpolating, for the output data location (4), the input data values of the closest input data locations (5) of each of the at least one determined triangle (7) to generate an output data value (3) corresponding to the output data location (4).
Abstract:
The present invention is concerned with a master control system layer for a Voltage Source Converter (VSC) based Multi-Terminal High Voltage Direct Current (MTDC) system. The invention is applicable to general topologies of the MTDC grid, including meshed topologies and isolated islands, and its benefits become specifically apparent in MTDC systems with five or more terminals where management of all possible different operating condition will require unacceptable engineering efforts if only simple feedback control loops are used. The invention includes mathematical optimization procedures to determine, in real-time and based on actual operating conditions, controller settings that minimize a cost criterion or optimize any other objective function. Controller settings include set-points or reference values as well as controller parameters such as droop constants or gains. Furthermore, it introduces model predictive control to include predictions of the effect of control actions on the system state evolution and predictions of future operating conditions in the optimization procedure.
Abstract:
A method of controlling an electricity generating system that includes at least one intermittent energy source generating plant (42, 44, 46, 48, 50), the method comprising: calculating actual operating parameters of the at least one intermittent energy source generating plant; calculating forecast operating parameters of the at least one intermittent energy source generating plant;generating intermittent energy source contingency definitions from such actual operating parameters and forecast operating parameters;analysing the intermittent energy source contingency definitions to provide contingency analyses; and controlling the electricity generating system in dependence upon such contingency analyses.
Abstract:
The present invention is concerned with a converter control unit or power system stabilizing unit for counteracting oscillations in electric power systems (1) that is equipped and employed to provide and processes information for system-wide monitoring, protection, control and metering. It comprises means (30) 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 (35) for calculating phasors, i.e. time stamped amplitude and phase angle of the voltages and/or currents.
Abstract:
Methods for detecting network model data errors are disclosed. In some examples, methods for detecting network model data errors may include splitting a network model into a first plurality of portions, executing an algorithm on each of the portions, identifying a portion for which the algorithm is determined to be non- converged, splitting the identified portion into a second plurality of portions, repeating the executing, identifying and splitting the identified portion until a resulting identified portion is smaller than a predefined threshold, and examining the resulting identified portion to identify plausible data errors therein. In some examples, examining the resulting identified portion to identify plausible data errors therein may include executing a modified algorithm, which may include an augmented measurement set, on the identified portion.
Abstract:
A method for detecting islanding conditions in a low voltage (LV) electric power network, wherein the electrical power network comprises a plurality of sub-networks. The sub-networks comprise at least one power electrical unit and are separable from each other and a main grid supplying the network by switching devices. The method comprises 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 means for each sub-network of interest, and sending, on the basis of the islanding conditions detected by using the detecting means, a disconnect signal to at least one power electrical unit in at least one sub-network of interest.
Abstract:
The present invention is concerned with the combined voltage or power flow control and damping of electromechanical oscillations in an electric power system (2) by Flexible AC Transmission System (FACTS) devices (20) or High Voltage DC (HVDC) transmission devices. To this end, information about a state or operating point of the power system is generated from suitable second system signals (y 2 ) and a control parameter (cp) of a FACTS controller (1) is derived therefrom. The control parameter and a first system signal (y 1 ) are used in the calculation of a control command (u) defining the settings of the FACTS device. Following a change in the state of the power system such as a change in the topology of a transmission network, poorly damped or even unstable oscillations are avoided by appropriate re-tuning of the control parameter of the damping or stabilizing equipment.
Abstract:
The invention is related to a method, resonance handling device and computer program product for handling resonances in a power transmission system. The resonance handling device (28) comprises a resonance frequency determining unit (22) configured to obtain measurements (y1, y2, yr) from measurement devices(12, 14, 16) in the power transmission system, apply the measurements in at least one state space model (M1, M2) and determine modal resonance frequencies(omegaj)in the system based on the application of the system measurements in said state space model, and an activity determining unit(24) configured to determine the modal activity of at least one of the resonance frequencies.
Abstract:
Methods for detecting network model data errors are disclosed. In some examples, methods for detecting network model data errors may include splitting a network model into a first plurality of portions, executing an algorithm on each of the portions, identifying a portion for which the algorithm is determined to be non- converged, splitting the identified portion into a second plurality of portions, repeating the executing, identifying and splitting the identified portion until a resulting identified portion is smaller than a predefined threshold, and examining the resulting identified portion to identify plausible data errors therein. In some examples, examining the resulting identified portion to identify plausible data errors therein may include executing a modified algorithm, which may include an augmented measurement set, on the identified portion.
Abstract:
The present invention is concerned with the damping multimode electromagnetic oscillations in electric power systems which interconnect a plurality of generators and consumers. A controller for damping such oscillations having a phasor measurement unit (PMU) and a power oscillation damper (POD) controller is described. Each oscillating mode signal is damped and then superposed in order to derive a control signal. A feedback controller is used to feedback the control signal to a power flow control device in the power system.