260 results about "Phasor measurement unit" patented technology

Provided is a system for transmitting synchronized phasors over a wide area network. The system generally includes a plurality of phasor measurement units (PMUs). Each of the PMUs are associated with a secured portion of a power system and measure power system data from the secured portion of the power system associated therewith. The power system data is associated with a time-element. A power system data concentrator is further provided in communication with the phasor measurement units such that it aggregates and time-correlates the power system data. A server is further provided in communication with the power system data concentrator. The server includes a program for transferring the aggregated time-correlated power system data from the secured portion of the power system to a non-secure network.

A state-matrix-independent dynamic process estimation method in real-time for weakly observable measurement nodes without PMU is only dependent on real-time measurement dynamic data of measurement nodes with Phasor Mesurement Unit (PMU) and measurement data of Supervisory Control And Data Acquisition (SCADA) system in electric power system or state estimation data. According to the SCADA measurement data or state estimation data at some continuous moments, the method utilizes recursive least squares solution to find a linear combination relationship between variation of measurement parameter to be estimated of nodes without PMU and variation of corresponding measurement parameter of nodes with PMU. Using the linear combination of relationship, the dynamic process of measurement nodes without PMU is estimated in real-time. The method provides high estimation precision and meets error requirements of engineering application.

In one aspect, a computer system for managing occurrences of data anomalies in a data stream is provided. The computer system includes a processor in communication with the data stream. The processor is programmed to receive a first data stream from a phasor measurement unit. The processor is also programmed to calculate at least one singular value associated with the first data stream. The processor is further programmed to detect a first data anomaly within the first data stream using the at least one singular value. The first data anomaly occurs during a first time segment. The processor is also programmed to indicate the first time segment as containing the first data anomaly.

The invention relates to a two-end distance measuring method of transmission line fault under a dynamic condition, comprising the following steps of: acquiring two-end voltage and current signals through two-end phasor measurement units of the transmission line; then acquiring dynamic positive sequence impedance, admittance, wave impedance and propagation coefficients according to line parameter estimation and a dynamic line parameter method; and finally solving a nonlinear equation related to a fault distance according to the fact that positive sequence voltages derived from two ends to a fault point are equal by applying a Newton iteration method so as to obtain a dynamic distance measuring result of the transmission line fault. The two-end distance measuring method can more effectivelysolve the problem of line parameter and fault distance estimation under the dynamic condition and has accurate and reliable fault distance measuring result.

The invention concretely discloses a wide area measurement system which is applied to a phasor measurement unit and based on local frequency spectrum analysis, which comprises a WAMS main station, a PMU substation and a power data network; the PMU substation comprises a GPS time service unit, a synchronized phasor acquisition unit, and a data centralized processing unit; the WAMS main station sends measurement and configuration information, measurement information to be detected and thresholds of a plurality of low-frequency oscillation parameters and receives the parameters measured by low-frequency oscillation which exceed the thresholds and return from each PMU substation for comprehensive analysis in order to obtain overall oscillation mode information; the PMU substation also comprises a frequency spectrum analysis unit and a low-frequency oscillation detection unit. The invention also discloses a phasor measurement unit based on the local frequency spectrum analysis. The adoption of the system and device of the invention can realize real-time and rapid low-frequency oscillation detection and analysis of a large-scale electricity grid.

The invention belongs to the technical field of electric system operation and control, and particularly relates to an electric system state estimation method of a Phasor Measurement Unit-PMU based on an interpolation matrix. According to the method, during the updating interval period of SCADA measurement, a state, obtained through a PMU interpolation, of an area U is equivalent to prior state information of the area U, the prior state information is continuously updated at each sampling instant of the PMU, the interpolation matrix is updated when SCADA measurement and PMU measurement reach simultaneously at the next moment, and therefore the real-time running state of each node of the area U is worked out. The method has the advantages of being high in accuracy and sampling speed of PMU measurement, and can track the running state of the system accurately in real time.

Phasor Measurement Units (PMUs) tend to be specialized and expensive—relegated to only key points in power distribution networks, and are generally reliant on GPS technology. The present disclosure details how any smart meter—using wireless communication—can perform sub-microsecond-grade synchrophasor measurements. Other aspects concern smart meter-based determination of A, B or C phase of the tri-phase power network. This can involve count-stamp enabling message packets sent to and/or from a smart meter, and then associating such count-stamps to local measurements of power phase by a metrology unit. Once a network of such enabled smart meters and other devices is formed, sub-microsecond metropolitan-wide and entire region-wide synchronizing time standard can calibrate local measurements of power phase, where simple A, B and C phase determination is one low hanging fruit application of such. Low cost aggregate monitoring of metropolitan-wide synchrophasors promises a next chapter of importance for that relatively recent art.

The invention relates to a detection method of a phasor measurement unit (PMU), which comprises the following steps: firstly, establishing various needed waveform library based on the test items, then establishing a circuit diagram with a PSCAD tool and adjusting each parameter according to the test demands to form various waveforms; when in test, selecting a corresponding .seq file or a waveform file of a COMTRADE format according to the test items; playing back the .seq file or COMTRADE file by using an Omicron relay protection testing device; when in playback of the .seq file, setting a waveform playback time in the 'GPS Set' to play back the waveform in a prescribed moment; executing data acquisition by using a PMU, and then delivering messages to main station simulation tool software through a communication protocol; reading the protocol message in virtue of the PMU synchronized phasor data analysis software, and converting and storing the message into the amplitude and phase data; performing frequency analysis for a static measurement precision test; and finding the optimal range of device measurement precision.

The invention relates to an assessment method for transient voltage stabilization of a load area of an electrical power system and belongs to the electrical power system stability analyzing and assessment field. The assessment method for the transient voltage stabilization of the load area of the electrical power system includes that using data measured by a synchronous phasor measurement unit as basis, and building an initial sample database for data mining through a lot of simulation samples; extracting characteristics for reflecting the stabilization degree of each node through the quantitative evaluation for each node in the area; identifying through a multiple linear regression method to obtain sensitivity coefficients for reflecting the mutual influence relations between the nodes in a local area network; using a semi-supervised clustering method to demarcate all the samples; using a decision tree algorithm to perform classified learning to obtain a decision tree model, and using the decision tree model for online monitoring to assess the global transient voltage stabilization state of the load area of the electrical power system.

The invention provides a big data fault detection and positioning method for a power distribution network, and belongs to the field of intelligent power grids. The method comprises the steps: receiving voltage sampling data of the power distribution network through employing PMUs (Phasor Measurement Units); carrying out the preprocessing of voltages received by all PMUs, and constructing a receiving matrix; obtaining an unbiased estimated value of a receiving data covariance matrix through employing a random matrix theory; carrying out the eigenvalue decomposition of the covariance matrix, and obtaining a corresponding principal component; calculating a linear regression coefficient through employing PCA (Principal Component Analysis); comparing a relative approximation error and a threshold value, and achieving the fault detection and positioning of the power distribution network. The method provided by the invention solves a problem that the conventional covariance matrix estimation is biased under the measurement of a plurality of PMUs, and can achieve the real-time fault detection and positioning of the power distribution network.

The invention discloses a method and a device for dynamically testing a synchronized phasor measurement unit (PMU) in a power system. The method comprises the following steps: setting up a simulation model comprising a generator unit, a transformer, circuits, a load and an equivalent power grid on an RTDS (Real-Time Digital Simulator) platform; utilizing the simulation module to simulate the dynamic characteristics of the power system and detecting the PMU of the synchronized phasor measurement unit through real-time simulation tests. The method and the device are convenient to realize, the performance of the PMU can be correctly and reasonably detected and evaluated, and the further development of a PMU technology is better promoted. The test requirements of laboratories on the dynamic performance of the PMU are met, an effective means is provided for network access detection, the work requirements of manufacturers on product development, delivery inspection and the like are met, and the quality of the synchronized phasor measurement unit in the power system is specified and ensured. The method and the device have great meaning in improving the running reliability of the power grid.

The invention provides a convolutional neural network power system intelligent fault detection method and system based on Spearman level correlation, and the method comprises the steps: setting a phasor measurement unit at a regional network node, and carrying out the measurement of data; performing Spearman correlation analysis on the acquired data, and proposing an image generation method basedon an analysis result; establishing an equivalent fault network, verifying the relation between the fault characteristics and the Spearman level correlation, and demonstrating the feasibility of the method; taking the generated image as an initial convolutional layer, and establishing a convolutional neural network architecture based on Spearman level correlation; and verifying the rationality andsuperiority of the method based on PSCAD/EMTDC according to the established architecture. A plurality of types of electric quantity data are comprehensively used for fault diagnosis, the position ofa fault in the power system can be quickly and accurately identified through the convolutional neural network, the problems that the power system has volatility and the traditional detection method isinaccurate due to addition of a distributed power supply and the like are solved, and the robustness and the self-adaptability of the power system are higher.

This is a nonlinear dynamic state estimation method based combined measurement by PMU and SCADA. A static module is established on the history data of SCADA. In case of non-measurement for part of nodes, conduct an accurate measure on adjacent nodes by PMU. An estimation on the non-measured nodes is made by Gauss-Seidel method.

Phasor Measurement Units (PMUs) tend to be specialized and expensive—relegated to only key points in power distribution networks, and are generally reliant on GPS technology. The present disclosure details how any smart meter—using wireless communication—can perform sub-microsecond-grade synchrophasor measurements. Other aspects concern smart meter-based determination of A, B or C phase of the tri-phase power network. This can involve count-stamp enabling message packets sent to and/or from a smart meter, and then associating such count-stamps to local measurements of power phase by a metrology unit. Once a network of such enabled smart meters and other devices is formed, sub-microsecond metropolitan-wide and entire region-wide synchronizing time standard can calibrate local measurements of power phase, where simple A, B and C phase determination is one low hanging fruit application of such. Low cost aggregate monitoring of metropolitan-wide synchrophasors promises a next chapter of importance for that relatively recent art.

Exemplary embodiments of the present disclosure provide a method and controller for damping multimode electromagnetic oscillations in electric power systems which interconnect a plurality of generators and consumers. The controller for damping such oscillations includes a phasor measurement unit (PMU) and a power oscillation damper (POD) controller. Each oscillating mode signal is damped and then superposed to derive a control signal. A feedback controller is used to feedback the control signal to a power flow control device in the power system.

A real-time distributed wide area monitoring system is presented. The real-time distributed wide area monitoring system includes a plurality of phasor measurement units that measure respective synchronized phasor data of voltages and currents. The real-time distributed wide area monitoring system further includes a plurality of processing subsystems distributed in a power system, wherein at least one of the plurality of processing subsystems is configured to receive a subset of the respective synchronized phasor data, process the received subset of the respective synchronized phasor data to determine respective system parameters, wherein the plurality of processing subsystems are time synchronized.