A cooperative voltage sensor (CVS) issues a target voltage change request when a voltage moving average at an end thereof deviates from a proper voltage upper or lower limit value. A cooperative voltage controller (CVC) also can issue a target voltage change request when a voltage moving average at an end thereof deviates from the proper voltage upper or lower limit value. The target voltage change request issued by the cooperative voltage sensor (CVS) or the cooperative voltage controller (CVC) is transferred between cooperative voltage controllers (CVCs) via a communication network and notified to all the cooperative voltage controllers (CVCs), and a cooperative operation of voltage control is realized.

An object of the invention is to economically operate a voltage reactive power control device by reducing a transmission loss and reducing the number of tapping operations affecting the life span of a facility. Provided is a voltage reactive power control device including a central monitoring device that includes a loss prediction information output unit calculating a bus voltage on the basis of a generation probability of a power generation pattern, and outputting loss prediction information associated with the bus voltage from system configuration information, and includes a control amount determination unit determining a control pattern of the voltage reactive power control device from the loss prediction information. According to the invention, it is possible to economically operate a voltage reactive power control device by reducing a transmission loss and reducing the number of tapping operations affecting the life span of a facility.

Methods, systems, and computer program products for determining severity of a geomagnetic disturbance on a power grid using similarity measures are provided herein. A method includes extracting multiple features of activity associated with geomagnetically induced currents from multiple heterogeneous data streams; comparing the extracted features to historical data related to geomagnetically induced currents to determine a level of similarity between each of the extracted features and the historical data; assigning a level of severity to one or more of the extracted features having a level of similarity with the historical data above a given threshold; and generating a notification comprising (i) a prediction of activity associated with geomagnetically induced currents based on the extracted features having a level of similarity with the historical data above the given threshold, and (ii) the level of severity assigned thereto.

A plurality of measurement signals may be evaluated to detect a poorly damped oscillation mode in an electric power delivery system. An oscillation mode of interest may be detected, and the oscillation mode of interest may be analyzed using a frequency transform. A plurality of amplitudes of the oscillation mode of interest in each measurement signal may be determined using a sliding window. The plurality of amplitudes may be used to calculate a damping of the oscillation mode of interest. The damping may be calculated solving a linearized system of equations. The linearized system of equations may be a least square estimate of the damping based on the logarithm of each amplitude. If the damping indicates that the oscillation mode of interest is poorly damped, a control action may be taken.

The present invention relates to a method for static security assessment of a power system and a real time static security assessment system for assessing a power system, the power system having a plurality of generators, the plurality of generators being represented in the network by a plurality of voltage controlled nodes, wherein the method for static security assessment of the power system comprises receiving information of a present state of the power system, determining a Thevenin equivalent for each voltage controlled node, determining for each voltage controlled node on basis of the determined present state of the power system and determining a first representation of the network based on the determined Thevenin equivalents, determining a modified representation of the network, wherein the modified representation is a representation of the network having at least one contingency, wherein at least one Thevenin equivalent of at least one voltage controlled node is modified due to the at least one contingency, the modified network representation being determined on the basis of the modified Thevenin equivalents, calculating voltage angles of the modified Thevenin equivalents, and evaluating the voltage angles to determine whether the network having at least one contingency admit a steady state. Also a method of providing information on a real time static security assessment of a power system is disclosed.

A means and method for measuring precise voltage phasors on medium-voltage alternating current (AC) distribution grids, using existing distribution transformers as voltage sensors. The errors introduced by the distribution transformers are minimized by taking into account the transformer's vector impedance, combined with measuring the transformer secondary current phasor. The invention includes a means and a method of measuring the distribution transformer's vector impedance.

Power network monitoring systems are presented. In some embodiments, the system includes a master device installed in at least one substation among the plurality of substations, and slave devices installed in remaining substations except from the substation in which the master device is installed. Each of the slave devices may include a first PMU configured to measure data such as reactive/active power, magnitudes and phase angles of a voltage and current of the substation in which the slave device is installed. The master device may analyze data transmitted from each of the slave devices, may generate a command for taking action of a corresponding slave device based on an analyzed result, and may transmit the generated command to the corresponding slave device.

A phasor measurement unit (PMU) of the present disclosure measures phasor, i.e., magnitude and phase angle of voltage and current, and related data from a specific location on the electrical gird synchronized to a common time source. The time-synchronized phasor is called a synchrophasor. In a system of the present disclosure, a plurality of PMUs transmit the synchrophasors and related data to a phasor data concentrator (PDC), which aggregates and time-aligns the data for real time and post analysis. The PMU of the present disclosure further functions as a power quality meter determining at least one of symmetrical components' phasor, frequency, rate of change of frequency, high-speed digital inputs, analog fundamental power and/or displacement power factor.