A power management apparatus (EMS 200) activates an acquisition function when it is determined at each time point in a predetermined period that an integral power consumption exceeds a predetermined power consumption.

A method of using a power consumption measurement device: determining at least two first current sensor readings from the one or more main electrical supply conductors; calibrating the power consumption measurement device, comprising applying a Kalman filter; electrically coupling a first calibration load to the electrical power infrastructure; determining at least one second current sensor reading from the one or more main electrical supply conductors; re-calibrating the power consumption measurement device, comprising applying the Kalman filter; uncoupling the first calibration load from the electrical power infrastructure; determining at least one third current sensor reading from the one or more main electrical supply conductors; and determining a first electrical power used by the electrical power infrastructure of the structure. Other embodiments are disclosed.

The present invention provides a power management method and a power management device for a residential complex comprising one or more residential units or for an urban district, comprising a shared connection via which self-supplied electricity from a time-variable generation capacity is supplied to the mains power network from a decentralised self-supplied-electricity generation apparatus, and via which mains electricity is supplied to the residential complex or the urban district from the mains power network. The method is configured such that the demand not covered by the decentralised self-supplied-electricity generation apparatus is determined according to the mains supply level 1S of the electricity and the demand covered by the decentralised self-supplied-electricity generation apparatus is determined according to the self-supply level S of the electricity for the residential complex or urban district, time dependency of the electrical consumption of a residential unit is recorded, and electricity costs for the residential unit of the residential complex or of the urban district are determined by taking into account the determined time dependency of the mains supply level and the self-supply level, the recorded time dependency of the electricity consumption of the residential unit, and the relevant tariffs for mains electricity and self-supplied electricity.

The present application relates to an impedance estimation device and estimation method for a power distribution line, and particularly to an impedance estimation device and estimation method for a power distribution line that estimate the impedance of a power distribution line formed of power distribution wires from a pole transformer to a plurality of consumers and a plurality of lead-in wires.

A magnetic field sensing device can include two or more magnetic field sensors configured to detect a magnetic field in a current carrying conductor. The magnetic field sensing device also can include a phase detector electrically coupled to outputs of the two or more magnetic field sensors. The magnetic field sensing device further can include a phase indicator electrically coupled to the phase detector. The phase indictor can include a display that indicates when the two or more magnetic field sensors are in a position in relation to the current carrying conductor. Other embodiments are provided.

An apparatus for automatic power metering within a device is provided. The apparatus includes a metering element and communication elements. The metering element is coupled to a power factor correction circuit at one or more nodes within the device, and is configured to measure and process values on the nodes to generate one or more metering metrics for the device. The metering data includes input power consumed by the device, output power transferred to a load of the device, and power factor corresponding to the device. The communication elements are configured to receive the one or more metering metrics, and are configured to transmit the one or more metering metrics over a communications channel.

Provided are a method, an apparatus, and a system for testing an inertia coefficient and a damping coefficient of a grid-forming converter. The method includes: obtaining a filter capacitor voltage in a three-phase inductor-capacitor-inductor (LCL) filter, an inverter-side current, an output-side current, and an output three-phase voltage; outputting a frequency output signal and a phase output signal through frequency control; outputting a pulse width modulation (PWM) control signal based on the phase output signal, the filter capacitor voltage, and the inverter-side current, to control turn-on time of a power semiconductor switch; outputting an active power signal; processing the output three-phase voltage to obtain a real-time output frequency; obtaining the damping coefficient of the grid-forming converter based on the active power signal, the frequency output signal, and a related setting parameter; and obtaining the inertia coefficient of the grid-forming converter.

Strain sensors are attached to a workpiece, and resistance values of the strain sensors are measured with time while cutting the workpiece with a milling cutting machine. A power spectrum in a frequency domain is obtained by Fourier-transforming the resistance values measured with time. A power peak is found in the power spectrum to be outputted as a magnitude of vibration occurring during machining the workpiece. By attaching a strain sensor to a stamper of a plastic working machine, a resistance value of the strain sensor is measured while pressing a workpiece on a die with the stamper. A magnitude of the strain corresponding to the measured resistance value is used to obtain a corresponding plastic working force. By attaching the strain sensor directly to the workpiece, it is possible to monitor the state of the plastic working and/or cutting process of the workpiece with high precision at low cost.