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The correct functioning of data measuring systems is impossible without timely metrological examination and calibration of measuring channels. Uncalibrated channels can transmit unreliable data, leading to the poor monitoring and incorrect decision making. The overview of the current research in the field of measuring channels calibration shows the low research activity in this area and highlights...
Generally speaking, basic real-time measurements collected from different control centers have a time delay due to the transmission delay and data exchanges in the energy management system (EMS). Measurement errors resulting from both the raw measurement noise and time delay have undesirable effect on power system dynamic state estimation (DSE). In order to reduce measurement errors, accurate measurement...
In large-scale data classification tasks, it is becoming more and more challenging in finding a true class from a huge amount of candidate categories. Fortunately, a hierarchical structure usually exists in these massive categories. The task of utilizing this structure for effective classification is called hierarchical classification. It usually follows a top-down fashion which predicts a sample...
The current reckoning method is based on the system operation network and modeling to achieve current reckoning network model, using the link reckoning technique and branch current measurement to identification and calculation. Analysis current difference identification features, to identify bad data, then correct the bad data, on the basis of the revised branch current to determine the state changes...
Cell phones with GPS function as well as GPS loggers are widely used and we can easily obtain users' geographic information. However, still battery consumption in these mobile devices is main concern and then we are not allowed to obtain GPS positioning data so frequently. In this paper, we propose a stayed location estimation method for sparse GPS positioning data. After generating initial clusters...
This paper presents the design of Unscented Kalman Filter (UKF) for estimation of state space variables of permanent magnet synchronous machine (PMSM). The UKF is shown together with the field oriented speed control. At first, the position and the speed of PMSM are measured, and UKF is used only for a load torque estimation. It is indicated how differences in sampling time of the speed and the current...
This paper is motivated by the problem of two adversarial networked teams that collect information about each other and make decisions based on this information. This problem has applications in network security, economic decision making, and robotic soccer. From the perspective of one team, the quality of decision making can be improved with better methods of aggregating measurements of the other...
A system for evaluating instrument current transformer errors using a lock-in amplifier is described in the paper. The difference between the standard and the transformer under test is evaluated as the ratio error and the phase displacement. The attention is focused to measurement of errors at the range of primary currents less than 20% of the nominal value. The measurement accuracy of current and...
Power quality (PQ) analysis requires to calculate a lot of different parameters (e.g. unbalance, THD, harmonic powers, harmonic impedances, …) based on measured voltages and currents (fundamental and harmonics). Respective standards and data sheets of measurement equipment define the measurement accuracies only for these measured quantities. The resulting uncertainty of parameters derived from these...
Harmonics identification in distribution systems has always been a difficult task, due to the variety of the loads, more and more often nonlinear and unbalanced, and the spread of the harmonics along the grid. Typically, few real measurements are available in distribution systems, commonly in the HV-MV substations, whereas monitoring of power quality phenomena requires specific methodologies and measurement...
Harmonic emission assessment in a distribution network with existing background voltage harmonics is a challenge for Renewable Power Producers (RPP) aiming to achieve grid code compliance. Dynamic interaction of harmonic sources at a Point of Common Coupling (PCC) renders the general summation law in IEC 61000-3-6 impractical, as harmonic phasors do not conform to the addition of rms values using...
The repeatability of set/reset errors has been investigated in 40nm TaOx based ReRAM cells. Errors of the Low Resistance State (LRS) in specific cells are observed repeatedly, and such cells are recovered by DC read operation. When error cells are recovered, the LRS cell current of the recovered cells shows a sudden jump up to large cell current in certain set cycles. Then, the High Resistance State...
The work deals with researching robustness of information system for measuring of microcontrollers average power consumption. Defined the ways of ensuring robustness of the proposed method. Considered hardware for robustness of the proposed method and proposed methods of study of the robustness of the proposed method.
The knowledge of line parameters is fundamental for building a network model that can become the basis for all the monitoring and management applications. Network line impedances are employed, for instance, for the state estimation or for protection applications in relay setting. The Phasor Measurement Units (PMUs), thanks to the synchronized voltage and current phasor measurements, provide the accurate...
Assessing compliance with harmonic emission limits for utility-scale photovoltaic plants requires accurate measurements of harmonic voltages and currents at the point of connection. This paper evaluates the accuracy, reliability and temporal characteristics of harmonic measurement data obtained from a utility-size photovoltaic plant located in the Northern Cape province of South Africa. Measured harmonic...
The standard measurement method for soft magnetic materials can not measure the magnetic parameters in deep saturation. Using the measurement equipment for hard magnetic materials, which has strong excitation ability, the parameters in deep saturation can be measured, whereas the measurement error is very large. Based on the analysis of the error sources, this paper proposed a method to improve the...
According to the problem of high cost of standard apparatuses and complex operating for the traditional AC current measurement, this paper introduces a method to measure the AC current with high performance which is based on using digitizing system and the AC-DC difference calculable resistance. Compared verification tests indicate a maximum deviation of 2.3 × 10−5 between the digital sampling measurement...
Detection and analysis of bad data is an important sector of the static state estimation. This paper addresses single and multiple bad data in the modern phasor measurement unit (PMU)-based power system static state estimations. To accomplish this objective, available approaches in the PMU-based state estimation are overviewed, and their advantages and disadvantages are briefly explained. The largest...
Bayesian Compressive Sensing (BCS), introduced into wideband cognitive radio network (CRN), has been considered as a promising technique for its ability of accurately recovering a signal from far fewer samples than required by the Nyquist sampling theorem. However, as BCS algorithm modulates the number of measurements step by step through evaluating the error bars, it needs appreciable amounts of...
We provide the first analysis of a non-trivial quantization scheme for compressed sensing measurements arising from structured measurements. Specifically, our analysis studies compressed sensing matrices consisting of rows selected at random, without replacement, from a circulant matrix generated by a random subgaussian vector. We quantize the measurements using stable, possibly one-bit, Sigma-Delta...
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