A method for automatically categorizing disturbances in an electrical system includes capturing at least one energy-related waveform using at least one intelligent electronic device in the electrical system, and processing electrical measurement data from, or derived from, the at least one energy-related waveform to identify disturbances in the electrical system. In response to identifying a disturbance in the electrical system, each sample of the at least one energy-related waveform associated with the identified disturbance is analyzed and categorized into one of a plurality of disturbance categories. The disturbance categories may include, for example, (a) voltage sags due to upline electrical system disturbances, (b) voltage sags due to downline electrical system faults, (c) voltage sags due to downline transformer and/or motor magnetization, and (d) voltage sags due to other downline disturbances.

The application provides an apparatus, a system, a detector and a method. The apparatus includes: a power supply voltage detector, including: N buffers, an input terminal of a first buffer being connected to a clock signal, output terminals of other buffers being connected to the input terminal of an adjacent buffer; N latch chains, each of which includes M latches, a clock input terminal of each latch being connected to a clock signal, a D terminal of a first latch of each latch chain being connected to the output terminal of a corresponding buffer, Q terminals of other latches being connected to the D terminal of an adjacent latch, M and N being positive integers, the D terminal of each latch being connected to an area where a power supply voltage is to be detected; and a voltage regulation module connected to the Q terminal of each latch.

Provided is a method for analyzing the stability of a PMSG-WT connected to a weak power grid considering the influence of power control. New energy power generation mostly uses a perturbation and observation (P&O) method for maximum power point tracking, and nonlinear discontinuous links therein make stability analysis difficult. The present application analyzes the stability of the PMSG-WT connected to the weak grid system based on a describing function method, and fully considers the nonlinear discontinuous links in the power loop, thus making the analysis result more accurate. At the same time, the describing function method is a method that can quantitatively calculate the frequency and amplitude of oscillation. The analysis method of the present application can provide a powerful and good reference for oscillation suppression and controller design.

A system for resource monitoring and engagement, the system comprising: a server, coupled to an internet, comprising: a meter reading processor, configured to communicate with a resource monitor that is disposed within radio range of resource meters that transmit radio signals indicative of meter identifiers and current readings, where the resource monitor: determines whether the radio signals are of a fixed frequency or frequency hopping transmission protocol by scanning each of a plurality of channels for a time period and counting hits of desired meter identifiers within the each of the plurality of channels; decodes the radio signals according to a determined transmission protocol to obtain corresponding meter identifiers and readings; and transmits the corresponding meter identifiers and readings over the internet, and where the meter reading processor creates and updates a corresponding plurality of records in a resource database that indicate resource consumption of corresponding facilities; and an engagement processor, that causes an alert to be transmitted based on analyses of the resource consumption to provide notification of an unusual pattern of resource consumption.

An electrical power system including an electrical power connector, a contact configured to electrically connect a power supply to a load, a first sensor configured to sense a first characteristic of the electrical power connector, a second sensor configured to sense a second characteristic of the electrical power connector, and an electronic controller. The electronic controller configured to receive a first signal indicative of the first characteristic, receive a second signal indicative of the second characteristic, compare the first signal to a first threshold, compare the second signal to a second threshold, and dynamically adjust at least one selected from a group consisting of the first threshold and the second threshold. Wherein the dynamic adjustment is based on at least one selected from a group consisting of a measured or calculated parameter, an installation condition, an operational limit, a known operational behavior, and parameter threshold information.

A method for detection of a sub-synchronous oscillation in a power system includes measuring a three-phase measurement signal of an electric system value, analyzing the measurement signal to detect an oscillation component of the measurement signal having an oscillation frequency lower than a system frequency of the power system, deciding whether the detected oscillation component at the oscillation frequency qualifies as a sub-synchronous oscillation, and disconnecting a generator from the power system that might be affected by the sub-synchronous oscillation. To detect sub-synchronous oscillations with low computational effort and good accuracy, an amplitude of each phase of the oscillation component is calculated and compared against a threshold, a sub-synchronous oscillation is detected upon exceeding the threshold during a given time delay, and a fault signal is generated upon detecting a sub-synchronous oscillation. A device having a processing unit is also provided.

A measurement device, such as a power meter or power submeter, may comprise a frame disposed in a housing dividing an interior volume of the housing into a first volume and a second volume. An external power source is connected to the device in the first volume and the frame may serve as an insulative barrier between the first volume and an exterior it and the housing. The device may alternatively, or additional include, an user interface assembly that is configured to mounted in a same orientation regardless of an orientation of the device or housing of a device relative to the external power source.

A method for feeding electrical power into an electrical, three-phase supply network by means of an inverter device, wherein the electrical supply network has a three-phase line voltage with a first, second and third line voltage phase, comprising the steps: feeding the electrical power during normal operation if a fault-free operation has been identified for the electrical supply network, wherein during normal operation a positive sequence voltage and optionally a negative sequence voltage is recorded from the line voltage and a reactive current is specified at least depending on the positive sequence voltage and optionally depending on the negative sequence voltage, and changing to a fault operation if a voltage change in the line voltage meets a predetermined fault criterion, in particular if the voltage change exceeds a predeterminable minimum amount of change or a minimum amount of change gradient, wherein during the fault operation, at least directly after the change, the reactive current is specified depending on a space vector voltage.

A method for controlling a power grid includes using a communication device to receive first data messages with first phasor measurement data from a first phasor measurement unit. A reference device is used to determine a deviation between the first phasor measurement data and reference data. The first phasor measurement data are recognized as plausible when the deviation lies below a previously defined upper threshold value and/or above a previously defined lower threshold value. A corresponding grid control arrangement is also provided.

An electricity meter includes at least one input terminal, at least one voltage sensor, and at least one current sensor, and a processor unit arranged to acquire the voltage measurements and the current measurements, and to detect a first period during which the source current is less than a first predefined current threshold, and a second period during which the source current is greater than a second predefined current threshold, to acquire a first voltage measurement during the first period and a second voltage measurement during the second period, and to detect faulty clamping between at least one wire and the input terminal when at least one detection value representative of a difference between a first voltage measurement and a second voltage measurement is greater than or equal to a voltage threshold.