Synchronous measuring terminals 5 synchronously measure phasor quantity D101 of a voltage/current at respective measurement points 1 and 2. A data-set creating block 91 of a short-circuit capacity monitoring device 7 creates, for each measurement cycle t, a data set D102 containing n pieces of data based on the phasor quantities D101 of voltage and current. A phase correcting block 92 performs a phase correction on the phasor quantity using the data set D102 to create a data set D102, and a backward impedance estimating block 93 estimates a backward impedance D103 using the data set D102.

Electrical circuit control techniques in power systems are disclosed herein. In one embodiment, a supervisory computer in the power system can be configured to fit phasor measurement data from phasor measurement units into a Gaussian distribution with a corresponding Gaussian confidence level. When the Gaussian confidence level of the fitted Gaussian distribution is above a Gaussian confidence threshold, the supervisory computer can be configured to perform an ambient analysis on the received phasor measurement data to determine an operating characteristic of the power system. The supervisory computer can then automatically applying at least one electrical circuit control action to the power system in response to the determined operating characteristic.

Methods and systems for detecting a falling power line in a power transmission or distribution system are described. Electrical measurements at various points in the power distribution system are used to detect changes in a power line indicating that the conductor has broken or become disconnected. Upon detection, control mechanisms are used to deenergize the conductor while the conductor is falling and/or before it contacts the ground.

A method and system for use in controlling an electric network are provided. The system includes an Integrated Volt-VAr Control (IVVC) component configured to determine optimization parameters for slow dynamics electromechanical devices and fast dynamics DER devices coupled to the network. The slow dynamics devices are controlled by a present state of the electric network and a voltage rise table that is adaptively updated in real-time using a command output, or a power flow-based complete optimization routine that generates optimal setpoints for the traditional controllable assets and for at least some of the fast dynamics DER devices. The fast dynamics devices are controlled locally using a control algorithm that uses a reactive power contribution based on IVVC settings, based on photo-voltaic (PV) plant active power variations, based on power factor, or based on a voltage of the local electric network.

The embodiments herein are directed to monitoring in real time, power system data so as to provide insights into global operation of a power grid. Such a scheme disclosed herein utilizes rules, which are created by analyzing PMU measurement data, in order to detect the fault location (bus and line) and fault type. Three common types of faults in a power grid, single-line-to-ground (SLG), line-to-line (LL), and three phase faults, can be detected using the methods herein.

A system for monitoring electric current in a network comprising at least one electrical fuse including a protective body, and at least one interrogating device arranged to interrogate at least one current sensing unit. The invention also concerns a method to monitor electric current in a network, including the steps of: determining a current in the electrical fuse, for example, via a voltage drop measurement across a fusible resistor in the electrical fuse; transmitting current determinations from the current sensing unit, for example, to a central management device; and processing received data from the at least one current sensing unit.

The present application relates generally to Volt-VAR optimization for power distribution systems having advanced metering infrastructure (AMI). Distributed energy resources (DER) such as photovoltaic arrays are becoming prevalent in distribution systems. These DER systems inject power into the distribution system which can cause unfavorable changes, such as a rise in voltage across the feeder lines of the distribution system. Existing control proposals stiffer from a number of shortcomings, drawbacks and disadvantages. In some instances, traditional controllers for distribution systems with DER systems may require information related to the arrangement of the distribution system which is unknown and cannot be provided by the advanced metering infrastructure. There remains a significant need for the apparatuses, methods, systems and techniques disclosed herein.

The present invention comprises a partition-composition method and its equipment for online detection of transient stability of interconnected power system. The method consists of three parts. Firstly, according to the dynamic response data of the generators at the actual time, the key parameters of transient stability analysis of local areas can be obtained from local dispatch control center based on the wide area measurement system. Secondly, the key parameters of entire grid can be obtained using the uploaded parameters from the local area. Lastly, using the partition-composition method, parameters of an adjoint power system of the entire grid can be obtained. The equipment consists of 4 modules, including the first obtained module, transport module, the second obtained module and the composition module. Using these modules, transient stability data of entire grid can be obtained exactly without the limitation of network topology, system model and parameters. The present invention can be a beneficial and potential tool for the online analysis of power system transient stability with higher computation speed and lower storage requirement.

The present invention comprises a partition-composition method and its equipment for online detection of transient stability of interconnected power system. The method consists of three parts. Firstly, according to the dynamic response data of the generators at the actual time, the key parameters of transient stability analysis of local areas can be obtained from local dispatch control center based on the wide area measurement system. Secondly, the key parameters of entire grid can be obtained using the uploaded parameters from the local area. Lastly, using the partition-composition method, parameters of an adjoint power system of the entire grid can be obtained. The equipment consists of 4 modules, including the first obtained module, transport module, the second obtained module and the composition module. Using these modules, transient stability data of entire grid can be obtained exactly without the limitation of network topology, system model and parameters. The present invention can be a beneficial and potential tool for the online analysis of power system transient stability with higher computation speed and lower storage requirement.

Methods, systems, and controllers are described herein for controlling an electrical power system. A time-synchronized measurement of a phasor from one or more phasor measurement units is fed back to a feedback controller. Distributed energy resources of the electrical power system are controlled by the feedback controller using feedback control algorithms by sending, to distributed energy resources, a power setpoint derived from the time-synchronized measurement of the phasor.