Figure 1 shows the block diagram of the original design for the pmu. The paper provides a short history of the phasor measurement unit pmu concept. Synchronized phasor measurements synchrophasors provide realtime measurement of electrical quantities from across a power system. Applications of phasor measurement units pmus african journals. Power system state estimation using phasor measurement units. Implements a phasor measurement unit using a phaselocked. Ni software and api to develop test modules, manage test results, perform dut control, and connect to other software such as a manufacturing execution systems block diagram of typical vrts configuration vrts is compatible with third party rf measurement instruments and can be complemented with nis. Scalable and modular substation hardened phasor measurement devices for connection up to 10 3 phase circuits to calculate and stream phasors.
A phasor measurement unit pmu is a device used to estimate the magnitude and phase. The 65apmucal phasor measurement unit calibration system is the only fully automated and traceable pmu calibration system available today. Phasor measurement unit res670 ansi operators manual. The resultant phasor can be determined from the vector addition of the phasors. Due to its enhanced situational awareness capabilities, many applications of pmus are presented in the literature in the past decades. Plant engineering power measurement devices and how they. Synchronized phasor measurements have become the measurement technique of choice for electric power systems. Function block diagram an overview sciencedirect topics. Synchrophasor technology provides a tool for system operators and planners to measure the. The pmu will also require communication circuit connection modem if using 4wire connection or ethernet for network connection.
The signal can be a set of three balanced or unbalanced signals which may contain harmonics. Download scientific diagram block diagram of phasor measurement unit from. The lengths of the phasors are proportional to the values of the voltage, v and the current, i at the instant in time that the phasor diagram is drawn. A phasor measurement unit pmu or a synchrophasor measures electrical waves on grid. The vizimax phasor measurement unit pmu is a high accuracy platform for acquisition and fast data publishing current and voltage synchrophasors, current and voltage direct sequences, frequency and rocof for advanced high and medium voltage power system monitoring, protection and control. Phasor diagram and phasor algebra used in ac circuits.
Time synchronization is usually provided by gps and allows synchronized realtime measurements of multiple remote points on the grid. It connects to the line, measures instantaneous voltage and current, and then derives other measurements by calculating. Within data parameters, phasor measurement units generate a huge flow of points due to high scanning resolution 1ms. The software and hardware described in this document is furnished under a license and. There are two key pieces of software required to read, store and send the data. This has been made possible by the availability of global positioning system gps. This is where all information captured from the field via manual reading, automated control systems. Thus a block is represented in the manner shown in figure 5. Pmus have evolved into a practical tool for measurement of positive sequence associated with power system. The process required to run tests on the sel421 and the sel487 phasor measurement unit pmu hardware requires several steps and an understanding of the block diagram shown in figure 1. The watthour meter block diagram above illustrates how its components work together to register consumed electrical power. A function block is a program instruction unit that, when executed, yields one or more output values. Model validation using phasor measurement unit data. Applications include widearea control, system model validation, determining stability margins, maximizing stable.
Like no one device before, the n60 shares realtime operational data to remote n60s so the system can generate intelligent decisions. The first section of this paper will explain each block in figure 1 as it pertains to testing pmus. Phasor measurement unit pmu a device mostly microprocessor based which reports the magnitude and phase angle of an analog and or derived phasor with respect to the global time reference, as per the synchrophasor standards ieee 44, ieee c37. Phasor measurement unit pmu general protection siemens. Figure 2 schematic for communication module of openpmu 5. Matlab based simulink model of phasor measurement unit. A pmu is created in matlab which can be used as simulation software for. Applications of synchrophasor technologies in power systems. Measure threephase currents and voltages in circuit. A phasor measurement unit pmu is a device used to estimate the magnitude and phase angle of an electrical phasor quantity such as voltage or current in the electricity grid using a common time source for synchronization. Pmu phasor measurement unit consists of an anti aliasing filter,ad converter,gps unit,pll oscillator, microprocessor unit,modem transmitter etc. I would like to make the phasor vectors look like arrows. In addition, phasor measurement unit pmu measurements are applied in state estimation to verify if they could solve the divergence problem and improve state estimation accuracy.
The beauty of this device lies in its synchronized measurement of phasors at multiple remote measurement points in. The phasor measurement units provide synchronized positive sequence voltage and current measurements within a microsecond. The dissertation investigates the impacts of variations of line power flow increment and topology errors on convergence property of the wls state estimator. Phasor measurement units pmus and time synchronization. Phasor measurement unit databased states and parameters.
Open source software for electric power industry tesfatsion. Synchrophasors are measured by fast timestamped devices called phasor measurement units pmus to constitute the basis of realtime monitoring and control actions in the electric grid. Phasor handout, part 2 adding phasors bucknell university. One is the pmu streamreader software, provided by the aeso, used to read streaming data from the pmu and create and store. Worked on the design process for a project based on fault detection by phasor measurement unit pmu which uses synchro phasor concept.
Phasor measurement unit databased states and parameters estimation in power system by hossein ghassempour aghamolki a dissertation submitted in partial ful llment of the requirements for the degree of doctor of philosophy department of electrical engineering college of engineering university of south florida major professor. A pmu placement strategy is developed and analyzed on ieee 14 bus test system. The pmu pllbased, positivesequence block implements a phasor measurement unit pmu using a phaselocked loop pll, which computes the positivesequence component of the input abc signal over a running window of one cycle of fundamental frequency given by input abc. Phasor measurement units pmus and synchrophasors offer valuable contribution to the dynamic monitoring of transient processes in energy supply systems. Synchronized phasors synchrophasors provide a realtime measurement of electrical quantities from across the power system. Phasor parameters can be estimated in different ways. The second software application, cygwin, sends the files to the aeso. Kilowatt hours is only one parameter a digital power meter can measure. Nuqui, state estimation and voltage security monitoring using synchronized phasor measurements, doctorate dissertation, virginia polytechnic institute, blacksburg, va, july 2, 2001.
This paper proposes extended kalman filter ekf based dynamic state estimator for power systems using phasor measurement unit pmu data. Virtualization of synchronized phasor measurement units within. Synchrophasors schweitzer engineering laboratories. Phasor measurement units pmu is the modern technological device built in late 1980s to measure phasors of sinusoidal electrical quantities in the electric power grid.
It is related to a more general concept called analytic representation, which decomposes a sinusoid into the product of a complex constant and a factor that encapsulates the frequency. Application of phasor measurement units for disturbance. Block diagram of phasor measurement unit download scientific. Construction of a phasor measurement unit pmu for power. It is described as a graphical language for depicting signal and data flows through blocks, which are reusable software elements. The phasor diagram is drawn corresponding to time zero t 0 on the horizontal axis. Dynamic state estimation in power systems provides synchronized wide area system history of the dynamic events which is key in the analysis and understanding of the system performance, behavior, and the types of control decisions to be made for. The algorithms used are those from the paper exploring the relative performance of frequencytracking and fixedfilter phasor measurement unit algorithms under c37. The term function block diagram fbd is used for plc programs described in terms of graphical blocks. Phasor measurement units pmus history of pmus invented in 1988 at virginia tech 1st commercial pmu in 1992 1st synchrophasor standard. They can be used within matlab simulink simulations. This software contains executable examples of p and m class pmus phasor measurement units with frequency tracking and adaptive filters. The wams consists of several sensors known as the phasor measurement units pmus that collect.
Block diagram of pmu phasor parameters can be estimated in different ways. The role played by phasor measurement units pmu in power grid monitoring systems. In physics and engineering, a phasor a portmanteau of phase vector, is a complex number representing a sinusoidal function whose amplitude a, angular frequency. The phasor diagram for these two oscillations looks like this. The current phasor lags the voltage phasor by the angle. A matlab based simulink model of the phasor measurement unit and phasor data concentrator for data storage and a common reference time data is also developed in matlab. The steadystate voltage and current phasors measured by the threephase vi measurement block can be obtained from the powergui block by selecting steadystate voltages and currents. The n60 network stability and synchrophasor measurement system is a flexible device intended for the development of load shedding, remedial action, special protection schemes and wide area monitoring and control. The functional block diagram of the above microcontroller in micropmu prototype is given in fig. These values get a high precision time stamp and together with the values of power frequency, power frequency change rate and optional binary data that are also time stamped are transmitted to a central analysis station.
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