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.

The method for determining mutual voltage sensitivity coefficients between a plurality of measuring nodes of an electric power network does not rely on knowledge of the network parameters (for example: series conductance and susceptance of the branches, shunt conductance and susceptance of the nodes, etc.). The method uses a monitoring infrastructure including metering units at each one of the measuring nodes, and includes a step of measuring at the same time, at each one of the measuring nodes, repeatedly over a time window, sets of data including values of the current, the voltage, and the phase difference, a step of computing active power, reactive power and values from each set of measured data, and a step of performing multiple parametric regression analysis of the variations of the voltage at each one of the measuring nodes.

An online live line method of analysing metrological properties of a high voltage current transformer configured to transform an upstream current into a downstream current, the method comprising obtaining a series of upstream current data points during a first time period using an upstream current sensor, and attributing an upstream time stamp provided by an upstream global navigation satellite system (GNSS) signal receiver to each one of the series of upstream current data points to obtain a time-stamped series of upstream current data points. The method further comprises obtaining a series of downstream current data points during the first time period using a downstream current sensor; attributing a downstream time stamp provided by a downstream global navigation satellite system (GNSS) signal receiver to each one of the series of downstream current data points to obtain a time-stamped series of downstream current data points; and calculating a current transformer phase displacement error between the time-stamped series of upstream current data points and the time-stamped series of downstream current data points. The method further comprises calculating a current transformer ratio error by comparing a rated ratio of the current transformer with a measured ratio determined using the time-stamped series of upstream current data points and the time-stamped series of downstream current data points.

A three-phase power meter can monitor power on both 3-wire and 4-wire power lines. The power meter measures at least two voltages between phase conductors of the power line, and at least one voltage between a phase conductor and a neutral conductor of the power line when the neutral conductor is available. Using at least some of the measured voltages, the power meter can then operate in a first mode when coupled to a 3-wire power line to determine power on the power line based on the measured voltages, or operate in a second mode when coupled to a 4-wire power line to determine power on the power line based on the measured voltages.

Online estimation of area-level inertia can be used for frequency stability control in low-inertia power systems. This disclosure provides an area-level inertia online estimation method considering inter-area equivalent frequency dynamics. The disclosed method only needs one phasor measurement unit placed at any bus within each area. The inter-area equivalent frequency dynamics model for the multi-area power system is developed, which is employed to estimate area-level inertia under the small disturbance situation. Then, the area-level inertia estimation model boils down to a nonlinear parameter identification problem. The other boundary conditions of the disclosed method are derived by parameter identifiability.

A smart plug designed to electrically connect a household appliance to power lines. The smart plug has an electronic controller configured to measure current and voltage of the electric power supplied to household appliance via a smart plug, determine electric quantities indicative at least of prefixed current harmonics and/or prefixed voltage harmonics, based on said measured current and voltage, determine load information which are indicative of electric loads of the household appliance being activated during an operating cycle performed by household appliance, based on determined electric quantities; determine the operating cycle performed by the household appliance based on the load information, communicate determined operating cycle to a network system.

In an embodiment, an electronic device includes a package power zone controller. The device monitors the overall power consumption of multiple components of a package. The package power zone controller may detect workloads in which the package components (e.g. different types of processors, peripheral hardware, etc.) are each consuming relatively low levels of power, but the overall power consumption is greater than a desired target. The package power zone controller may implement various mechanisms to reduce power consumption in such cases.

A device for extinction angle control of a high voltage direct current (HVDC) system, includes: a converter reactive power calculator calculating a reactive power variation amount of a converter included in the HVDC system, depending on firing angle control of the converter; an alternating current (AC) system short circuit level calculator calculating a short circuit level of an AC system by applying the reactive power variation amount to a short circuit level formula of the AC system connected to the HVDC system; an extinction angle variation value calculator calculating an extinction angle variation value of the converter, corresponding to the short circuit level; and an extinction angle controller controlling an extinction angle of the converter, depending on an extinction angle control value reflecting the extinction angle variation value.

A submeter for measuring electricity use collects information usage data from several sensors, such as circuit clamps which each measure usage within an individual circuit within a premises. The submeter is programmed for operation using an installation tool wherein an installer can enter configuration data defining the characteristics of each circuit (e.g., air conditioner circuit, swimming pool circuit, etc.), and transmit the configuration data to the submeter. The submeter can then transmit electricity usage data from the circuits, along with the configuration data, to an Intelligent Power Manager or other processor which can analyze and/or display energy usage among the various circuits.

A power measurement device includes: a first three-phase to two-phase converter converting a three-phase voltage signal of three-phase AC power into a two-phase voltage signal; a second three-phase to two-phase converter converting a three-phase current signal of the three-phase AC power into a two-phase current signal; an instantaneous power calculator calculating an instantaneous value of active power of the three-phase AC power and an instantaneous value of reactive power of the three-phase AC power based on the two-phase voltage signal and the two-phase current signal; a first moving average calculator calculating multiple active power average values of different moving average data quantities; a second moving average calculator calculating multiple reactive power average values of different moving average data quantities; and calculators that calculate average active powers corresponding to a frequency of the three-phase AC power, and the reactive power corresponding to the frequency of the three-phase AC power.