A description is given of an apparatus for disconnecting an electrical connection between solar modules of a photovoltaic string, the apparatus including a first and a second terminal for a respectively assigned solar module of the photovoltaic string, also a circuit breaker, a band-stop filter and a supply circuit for supplying energy to the apparatus, which are arranged in a series circuit with respect to one another between the first and second terminals. A bandpass filter for coupling out a high-frequency control signal from the electrical connection bridges the circuit breaker and the band-stop filter in parallel. In this case, a reverse current diode that is oppositely polarized relative to an operating current flow direction is connected in parallel with the circuit breaker or the partial series circuit comprising the circuit breaker and the band-stop filter.

A process bus-applied protection system includes a process bus, a plurality of MUs (merging units), and a plurality of IEDs (intelligent electric devices). Each of the MUs is configured to sample a current and a voltage of a power system at timing synchronized with a time synchronization signal received through the process bus. Each of the IEDs is configured to be capable of outputting the time synchronization signal to the process bus by serving as a transmission source, and receiving, through the process bus, the time synchronization signal from another IED. The plurality of IEDs have a predetermined priority. Each of the IEDs is configured, when the IED does not receive the time synchronization signal from an IED having a higher priority than that of the IED and serving as a transmission source, to output the time synchronization signal to the process bus by serving as a transmission source.

A method for managing power quality events in an electrical system includes processing electrical measurement data captured by an intelligent electronic device (IED) to identify at least one power quality event associated with one or more loads monitored by the IED. The IED and the loads are installed at respective locations in the electrical system. The method also includes determining an impact of the at least one identified power quality event on one or more of the loads, and using the at least one identified power quality event and the determined impact to generate a tolerance curve associated with the one or more of the loads. The tolerance curve characterizes a tolerance level of the loads to certain power quality events. The loads can include one or more loads downstream from the IED in the electrical system and/or one or more loads upstream from IED in the electrical system.

A method for managing voltage event alarms in an electrical system includes processing electrical measurement data from energy-related signals captured by at least one intelligent electronic device (IED) of a plurality of IEDs to identify an anomalous voltage condition at a point of installation of a respective one of the plurality of IEDs in the electrical system. In embodiments, the anomalous voltage condition corresponds to a measured IED voltage being above one or more upper alarm thresholds or below one or more lower alarm thresholds. The method also includes determining if the electrical system is affected by the identified anomalous voltage condition. In response to determining that the electrical system is not affected by the identified anomalous voltage condition, at least one of the one or more upper alarm thresholds or at least one of the one or more lower alarm thresholds may be adjusted to the measured IED voltage.

A method for quantifying power quality events in an electrical system including a plurality of intelligent electronic devices (IEDs) includes processing electrical measurement data from or derived from energy-related signals captured by at least one first IED of the plurality of IEDs to identify a power quality event at a first point of installation of the at least one first IED in the electrical system. An impact of the power quality event at a second point of installation in the electrical system is determined based on an evaluation of electrical measurement data from or derived from energy-related signals captured by at least one second IED of the plurality of IEDs at the second point of installation proximate to a determined time of occurrence of the power quality event at the first point of installation.

A method for characterizing power quality events in an electrical system includes deriving electrical measurement data for at least one first virtual meter in an electrical system from (a) electrical measurement data from or derived from energy-related signals captured by at least one first IED in the electrical system, and (b) electrical measurement data from or derived from energy-related signals captured by at least one second IED in the electrical system. In embodiments, the at least one first IED is installed at a first metering point in the electrical system, the at least one second IED is installed at a second metering point in the electrical system, and the at least one first virtual meter is derived or located at a third metering point in the electrical system. The derived electrical measurement data may be used to generate or update a dynamic tolerance curve associated with the third metering point.

A method for analyzing power quality events in an electrical system includes processing electrical measurement data from or derived from energy-related signals captured by at least one of a plurality of metering devices in the electrical system to generate or update a plurality of dynamic tolerance curves. Each of the plurality of dynamic tolerance curves characterizes a response characteristic of the electrical system at a respective metering point of a plurality of metering points in the electrical system. Power quality data from the plurality of dynamic tolerance curves is selectively aggregated to analyze power quality events in the electrical system.

This disclosure relates to systems and methods for verification of time sources. In various embodiments, one or more secondary time sources may be used to verify the accuracy of a primary time source prior to relying on a time signal created by the primary time source. In one embodiment, a first interface is configured to receive the primary time signal from a primary time source, and a second interface in communication with a secondary time source is configured to receive a secondary time signal. A time assessment subsystem is configured to determine an occurrence of a verification criteria. Upon the occurrence of the verification criteria, the system may compare the primary time signal and the secondary time signal to determine whether that the primary time signal is consistent with the secondary time signal. If the signal is consistent, the primary time source may be utilized by the system.

An electric power system includes an energy management system configured to control a generated power output level of one or more electric generator resources, and a configuration of two or more high-voltage transmission lines, for efficient operation based, at least in part, on a topology error estimation using binary values corresponding to switch statuses. Increased accuracy of network topology estimates facilitates improved state estimation, which in turn enables production of more highly optimized control of electric generator resources and configuration of high-voltage transmission lines.

Energy flow in a power grid system (e.g., an electrical energy distribution system) is managed. In an example embodiment, a system provides for generating monitoring data for an electrical energy distribution system based on power-flow data for the electrical energy distribution system and topology data for the electrical energy distribution system. The power-flow data is indicative of voltage values that are repeatedly obtained from the electrical energy distribution system. The topology data is indicative of a topology for the electrical energy distribution system. The system also provides for identifying, based on the monitoring data, a change in a voltage angle associated with a transmission line in the electrical energy distribution system. Furthermore, the system provides for generating a notification for a graphical user interface in response to a determination that the change in the voltage angle for the transmission line satisfies a defined criterion.