196results about "Power factor measurement" patented technology

A composite power quality indication generated from user weighted statistical contributions of selected system parameters provides an overall indication of power quality in an electric power distribution system. The user defined weightings are maintained over time by continually updating sensitivities that normalize the component contributions to the composite power quality indication. The current composite power quality indication is displayed in relation to its long-term mean and to dynamic thresholds determined as multiples of the standard deviation of the long-term mean.

Apparatus and methods are provided for the measurement of a power factor at points of interest, such as circuit breakers, machines, and the like. Accordingly, means are provided for measurement of a power factor for each electrical sub-network that is controlled by a circuit breaker. Each apparatus is enabled to communicate its respective data, in an environment of a plurality of such apparatuses, to a management unit which is enabled to provide finer granularity power factor profiles.

A method detects power theft in a branch of a distribution system by distinguishing between technical losses that are inevitable during the course of normal operation of the system, and non-technical losses that can be attributed to power theft. The method assumes a specific circuit corresponding to that branch, collects data for energy consumed and currents at regular intervals by means of a smart or traditional power meter, estimates the likely resistances of the lines connecting the consumption points to the distribution transformed by means of least squares regression, and uses the estimated resistances to predict technical losses in future time intervals. By comparing the total power losses measured during future intervals with the estimates of the technical losses, the amount of non-technical losses can be estimated, and theft can be signaled when this amount is unusually high.

A system for accurately determining real-time Available Transfer Capability and the required ancillary service of large-scale interconnected power systems in an open-access transmission environment, subject to static and dynamic security constraints of a list of credible contingencies, including line thermal limits, bus voltage limits, voltage stability (steady-state stability) constraints, and transient stability constraints.

A power monitoring system for electrical panels providing multi-phase power, with multiple current sensors. The disclosed power monitoring system preferably determines the instantaneous power provided to each of multiple loads by sensing the potential and phase of each conductor that supplies power to one or more of the respective loads.

The invention relates to a detection apparatus, a power receiving apparatus, a non-contact power transmission system and a detection method. The detection apparatus includes: a resonant circuit provided with a Q-factor measurement coil and one or more capacitors to serve as a circuit for receiving pulses; a response-waveform detecting section configured to detect the waveform of a response output by the resonant circuit in response to the pulses; and a Q-factor measuring section configured to measure a Q factor of the resonant circuit from the response waveform detected by the response-waveform detecting section. It is possible to increase the precision of detection of a metallic foreign substance existing between a power transmitting side and a power receiving side.

A method of compressing values of a waveform of a monitored electrical power signal. The method includes of acquiring data representative of periods of the waveform (202), decomposing the waveform of the power signal into a plurality of components, over a plurality of periods of the waveform (sequence steps 204, 206, 208, 210, 212, 214) compressing the values of at least some of the components over a plurality of periods (216), individually. And storing these values and extents (218).

A system for fault prediction in electrical systems. It includes a network of recording nodes that transmit data to multi-channel recorder. The nodes monitor power quality based on a number of system parameters. These data are assembled into data blocks and are analyzed to determine load factors for the system over time. Data blocks are collected over 22 cycle periods and are evaluated against a derived standard deviation factor for the given system. The standard deviation is used to determine alert and alarm levels. The constant monitoring allows the system to alert workers of a potential upcoming fault in one or more system components. In this way repairs can be made before the component fails and the system experiences a fault condition.

An integrated device suspended at a high voltage potential for the metering and protection of a distribution network comprises a measurement current transformer (CT), a protective CT and a voltage sensor. The voltage signal is output from the voltage sensor to an electric energy metering module and first and second electric signal acquiring modules. The current signal acquired by the measurement CT is output to the electric energy metering module. The current signal acquired by the protective CT is output to the first and second electric signal acquiring modules. The electric energy metering module processes the current and voltage signals and sends the processed data to a comprehensive control module. The first and second electric signal acquiring modules send the voltage and current data to the comprehensive control module. The comprehensive control module comprehensively calculates the received data and sends the result to a low voltage terminal.

The invention discloses a non-invasive method and a system for monitoring an electric load alarm. The method comprises the following steps: obtaining a terminal voltage and a total current at the inlet of an electric load power supply at the current moment; performing electric load characteristic extraction on the terminal voltage and the total current to obtain an electric load characteristic atthe current moment; performing electric load decomposition on the terminal voltage and the total current according to the current electric load characteristic; obtaining a type, a current working state and current electric consumption information of each electrical equipment in the electric load; and generating electric consumption abnormal alarm information of the electrical equipment according to the current electric consumption information and a reference electric consumption information. Once any of the current electric consumption information of the electrical equipment is abnormal, the system can timely discover it and give an alarm. Users can timely view and process the abnormal condition according to the type, the current working state and the abnormal electric consumption information of the electrical equipment with abnormal electric consumption in the abnormal electric consumption alarm information of the electrical equipment.

The invention relates to an intelligent monitoring system for the operation state of a low-voltage transformer area, and the system comprises a data collection module which is used for collecting operation parameter data; a topology identification data analysis module which is used for carrying out statistical analysis by utilizing a topology identification calculation model, identifying or verifying a box-table relationship and a user-transformer relationship to achieve topology identification mapping; and a topology identification imaging module which is used for visually displaying a data analysis result, dynamically generating a topological graph and performing real-time tracking verification, and supporting dynamic and conditional query of transformer area management, transformer areatopology, abnormity and analysis logs. According to the invention, a power grid safety power utilization management and safety operation and maintenance monitoring mode can be effectively realized, and a reliable basis is provided for overall planning and overall management of the power grid.

A method is provided of ascertaining an unknown line (conductor) voltage at point X on a power line within an electrical grid comprises collecting raw voltage at or about Point X using a sensor; gathering additional data from data collection sources upstream (comprising, for example a substation) and/or downstream (comprising, for example, smart meters) to Point X (constraining data); using raw voltage, and environment and line data (comprising at least one of GPS location of sensor, GIS data of the electrical grid, phase, type of conductor, total load on conductor), to calculate voltage range at Point X; and using constraining data sequentially to bind (narrow and tighten) the voltage range from a determined range of possibilities to a likely absolute voltage measurement.

A solid state drive (SSD) with improved techniques for testing power loss protection (PLP) capacitors and a method for testing PLP capacitors of SSDs is disclosed. In one embodiment, the SSD includes a memory controller and one or more non-volatile memory devices and a volatile memory device coupled to the memory controller. The SSD also includes a PLP capacitor configured to supply a first voltage to the memory controller, the one or more non-volatile memory devices, and the volatile memory device in the event of a power loss or failure of the SSD. In one embodiment, the PLP capacitor is further configured to increase the first voltage to a second voltage prior to testing the PLP capacitor. In another embodiment, the memory controller is configured to reduce a volume of data stored in the volatile memory device prior to testing the PLP capacitor.

A system and method for analyzing energy savings for a building is provided. The method includes receiving a schedule of occupied days, an occupancy behavior profile and historical energy usage data from which an hourly interval usage is determined. A set of occupancy thresholds is determined by season. Occupied days are determined from the set of occupancy thresholds and the hourly interval usage. The hourly interval usage is analyzed to determine occupied energy consumption in hourly intervals, occupied start and stop time savings, mechanical equipment savings and temperature setpoint savings during an occupied day. The hourly interval usage is also analyzed to determine unoccupied energy consumption in the hourly intervals and refrigeration savings, mechanical equipment savings, computer equipment savings, parking lot lighting savings, hallway lighting savings and temperature setpoint savings during an unoccupied day. Energy consumption, energy savings, operational comparisons and monetary savings are reported.

The invention discloses a practical estimation method for background harmonic impedance of an AC power grid and provides the practical estimation method based on different running working conditions of a convertor station for the background harmonic impedance of the AC power grid. Aiming at real-measurement data types which can be acquired, the harmonic impedance estimation can be obtained only byknowing background harmonic voltage amplitude and current amplitude of the power grid and phase difference between the voltage amplitude and the current amplitude, and background harmonic impedance estimation of the AC power grid is facilitated.

A power converter is provided with a totem-pole power factor correction (PFC) circuit for bridgeless line rectification, and current sensing circuit that can be selectively disabled to reduce unwanted current sense signal components and undesirable current transformer voltage stresses. The totem-pole PFC has at least a first leg with first and second switching elements coupled in series. A PFC inductor is coupled between an AC input on a first end and a node between the switching elements. The current sensing circuit includes a first transformer winding coupled in series with the first switching element, a second transformer winding magnetically coupled to the first winding and configured to deliver current from the first winding to a current sense terminal during an active phase for the first switching element, and a shunt circuit configured to disable the current sensing circuit during a freewheeling phase for the first switching element.

Provided are an analysis apparatus and an analysis method which are capable of recognizing a local state change of an internal structure of a secondary battery. The analysis apparatus includes: an observation cell that houses a secondary battery; a charging and discharging controller that controls charging and discharging of the secondary battery; an image pickup device that captures color images of the secondary battery at a predetermined time interval; and a charging and discharging data detection unit that acquires charging and discharging data on the secondary battery during charging and discharging. Color image signals output from the image pickup device and charging and discharging data signals output from the charging and discharging data detection unit are supplied to a signal processing device. The signal processing device outputs a unit that temporally links time-series color image signals and time-series charging and discharging data signals, and designated analysis data.

The invention discloses a power grid broadband oscillation wide-area real-time monitoring system and a power grid broadband oscillation wide-area real-time monitoring method. The system includes: a plant station end broadband oscillation real-time monitoring and early warning module and a main station end broadband oscillation wide-area real-time monitoring and analysis module. The plant station end broadband oscillation real-time monitoring and early warning module is used for monitoring low-frequency oscillation, sub/super-synchronous oscillation and higher harmonic/inter-harmonic oscillation of a power grid at a plant station end in real time. When the oscillation exceeds an oscillation alarm/early warning threshold value, an oscillation alarm/early warning signal is sent out, and the oscillation alarm/early warning signal and oscillation monitoring data are transmitted to the main station end broadband oscillation wide-area real-time monitoring and analysis module; and the main station end broadband oscillation wide-area real-time monitoring and analysis module is used for carrying out real-time monitoring on the broadband oscillation wide-area level of the power grid and accident analysis on the wide-area level after oscillation according to the received oscillation alarm signal and oscillation monitoring data. According to the invention, a new support means can be provided for operation monitoring and safety control of the power grid, and absorption of new energy such as wind power and photovoltaic power can be promoted on the premise of guaranteeing the operation safety of the power grid.

This instant disclosure provides a device and a method used to measuring a real power transmitted by the power line. The device comprises a detecting unit and a calculating unit, for obtaining the power factor and the real power according to a sensing voltage signal and a sensing current signal. The device is characterized by: the detecting unit having an electric field detector and a magnetic field detector, two electrodes of the electric field detector respectively disposed adjacent to the power wires, the sensing voltage signal being the voltage difference between the two electrodes, two coils with metal cores of the magnetic field detector respectively disposed adjacent to the power wires, the winding directions of the two coils being contrary, the two coils being coupled in series based on the same sensing current direction for obtaining the sensing current signal.

The invention discloses a power factor correction circuit, a control method and a controller. The conduction time of a main switch tube of a switch type regulation circuit is adjusted according to measured total harmonic distortion, and the total harmonic distortion is minimized while power factor correction is carried out, so that special compensation design does not need to be performed aiming at a certain type of factors influencing total harmonic distortion indexes independently, and the overall control method is simplified.

Aiming at problems that cost of a traditional relay protection device is high, acquisition precision is not high, measurement data is not complete and measured electric energy precision is low, the invention provides a relay protection device based on a 12-bit AD in a SOC chip. A technical scheme is characterized in that a power grid frequency is stored in a CPU module; the CPU module reads a frequency value and makes an acquisition frequency of an AD module which collects data in a period be consistent with a frequency of one period in a power grid; an ADC port in the AD module works under a multi-loop acquisition mode; a pulse counting method is used to accumulate electric energy and time 10ms is taken as a statistics period; an accumulation result is divided into two integers which are stored in an RAM; and one integer stores a pulse value and another integer stores an integer electrical degree. In the invention, a hardware circuit is simplified; under the condition that CT is measured, measured values of active power, reactive power, apparent power, a power factor and four-quadrant electric energy can be provided, and electric energy precision can reach a 0.5S grade.