Units of measurement

This article discusses the method of integer linear programming, a method based on estimating the rate of change in operating conditions when conditions become more complex or disturbances occur. In the first method, the criterion for placing PMUs in the energy system of Azerbaijan is to ensure full observability; the second method examines the rate of change in the relative angles of synchronous generators under large disturbances. Based on the obtained parameters, weak nodes are identified where it is necessary to install PMU devices.

There are two major lifts in weightlifting competition: the snatch and the clean and jerk. Most studies have focused on the snatch technique using conventional motion capture systems. There is a lack of information on the bilateral comparison of body segment movement during the entire phases of the weightlifting exercises. To our knowledge, no previous studies have directly compared the joint kinematics between the snatch and clean lifts. In this study, we investigated the trunk, shoulder, elbow, hip, and knee joint movements to find a difference between the snatch and clean lifts at each phase using wearable inertial sensors. Seven female Mongolian weightlifters participated. Each participant performed three snatches and three clean lifts at 70% of the onerepetition maximum. The joint angles were calculated using raw data from the inertial measurement unit (IMU) sensors. The main phases of the two techniques were defined based on knee and shoulder angle. The mean joint angle, the joint angle at each phase, and the proportion of the phases were compared between the two techniques. The mean angles of the trunk, shoulder, and elbow movements were significantly different (p < 0.05) while the hip (p = 0.73) and knee movements (p = 0.06) were similar. With detailed statistical analysis at each phase, subtle differences in the joint angles were observed. This study provides a detailed comparative analysis of the joint kinematics between the snatch and clean, which may help to deeply understand the similarities between the two techniques and enable us to best prescribe the appropriate exercises for improving weightlifting performance.

The combination of ultrawideband (UWB) radios and inertial measurement units (IMU) can provide accurate positioning. To ensure reliable communication, the radios are generally mounted at the extremities of a mobile system whereas the IMUs are located closer to the center of gravity for use in control, resulting in a spatial offset between the IMU and the UWB radio. Additionally, data from heterogeneous sensors can arrive at different time instants. The systematic fusion of data from multiple sources requires the temporal offset and spatial offset between the sensors to be known. An important aspect of calibration is the observability of the system state and identifiability of the system parameters. Estimating the state or parameters of a system that is otherwise unobservable or unidentifiable, can result in poor estimates. In this report, the local weak observability of the state and the identifiability of the temporal offset for a tightly-coupled UWB-aided inertial localization system is studied.

State estimation (SE) is a critical must run successful unit within energy management system software. This is dictated by the high reliability requirements for system security and control and the need to represent the closest real-time model for market operations. There has been considerable emphasis in bringing phasor measurements into SE to improve performance. However, there are many practical problems in incorporating phasor measurements into SE. The higher reporting rates of phasor measurement units compared with supervisory control and data acquisition devices is one such problem. The disparity of the reporting rates raises the question of whether buffering the phasor measurements helps to improve the state estimates. This buffer is a subset of the entire phasor measurements set relevant to every particular instant at which SE is conducted. This paper describes the design of an optimal buffer, the use of the phasor measurements from that buffer, and the analysis of the impact on SE with the inclusion of these buffered phasor measurements. This hybrid SE, used for analysis purposes, is created from contemporary real-time system data and measurements from a utility in southwest USA.

Phasor Measurement Unit (PMU) is an emerging technology in Electric Power Systems which has many advantages in Wide Area Disturbance Analysis, Protection and Control. In order to utilize the benefits of this technology and to arrive at common way of representing, reporting and utilizing Phasor measurements, the IEEE standards committee revised the existing 1344 standard for synchrophasors and recently published "IEEE Standard for Synchrophasors for Power Systems-C37.118-2005". The new standard mandates compliance levels (level 0 and / or level 1) for the PMU under steady state conditions. This paper discusses the calibration and testing of TESLA 3000 PMU -a software module available with the TESLA Disturbance Fault Recorder (DFR) and the challenges of testing the PMU as per the new synchrophasor standard. The possible sources of errors and the current state of the art of the calibration equipment which qualifies for PMU testing will also be discussed. which explains the meaning , convention and communication aspects of the PMU. Very few literatures are available on the calibration and testing of PMU. The NASPI [2] is actively involved in improving the concept of understanding the PMU behaviour during dynamic conditions under a number of task forces. One of the Performance Requirement Task Team (PRTT) is involved in addressing the calibration and testing of the PMUs. This paper focuses on the calibration and testing PMU with the TESLA 3000 DFR using Doble F6150 test instrument.

It is critically important to understand steadystate and dynamic performance of phasor measurement units (PMUs) to ensure reliable and secure operation of the synchrophasor based wide area monitoring, control, and protection systems. The recently published IEEE Standard C37.118.1 provides necessary guidelines to characterize both steady-state and dynamic performance of a PMU. This paper presents a performance evaluation methodology according to the IEEE Standard C37.118.1 and discusses the practical issues in the test environment. Results of the steady-state and dynamic responses tests on an actual PMU are also presented. The PMU performance evaluation approach of this paper is simple, repeatable, and can be performed at any facility with commonly available standard signal playback equipment. The method is based upon using test signals that are mathematically generated from a signal model and play backed into the PMU with precise global position system (GPS) synchronization. Index Terms-Discrete Fourier transform, finite impulse response, global position system (GPS), phasor measurement unit (PMU), playback device, step response, total vector error (TVE).

Different power system applications based on synchrophasors measured in different nodes of the electric grid require information about the statistical distribution of the errors introduced by the phasor measurement units (PMUs). The performance of these applications can be significantly affected by possible incorrect assumptions. The Gaussian distribution has been historically assumed in most of the approaches, but some more recent studies suggest the possibility of considering different distributions for more accurate modeling of the actual situation. In this article, proper statistical tools applied to the results achieved through a high-performance experimental test system are proposed to assess the statistical distribution of PMU errors under controlled steady-state conditions, thus providing a basis for defining suitable models to be used in specific applications.

Vertical jump performance analysis allows for assessing the ability of the lower limb to generate mechanical power. The analysis performed with inertial measurement units (IMUs) is affected by inertial effects of wobbling masses. To compensate for them, an automated method was developed to estimate peak and mean concentric power based on anthropometric and time-frequency features. IMU data of 47 countermovement-(CMJ) and 50 squat-jumps (SJ) performed by 17 participants were used. Force platform data were used to obtain reference power values. Features were chosen according to the best subset regression method, devising a multiple linear regression for each estimated power parameter and jump. The regressions explained 88% and 96% variation, for CMJ peak and average power respectively, while explaining 75% and 74% of the variation for the SJ.

The half-squat is the most widely used exercise in the resistance training, which must be considered optimal only if it is specific and safe. Safeness relies, with other factors, in using the correct technique and being provided with adequate monitoring and feedback. In this perspective, this study a) provided a thorough characterization of the less dangerous squat technique, and b) showed how wearable inertial measurement units (IMU) can be used to quantify key variables useful to reduce errors. The IMU estimate presented a good concurrent validity (r=0.91) for trunk maximal forward inclination, although with significant mean systematic bias of 7±5 deg, and fair concurrent validity for pelvis and barbell rotations in the frontal plane with lower systematic biases. Thus the use IMUs to provide practitioners a quantitative feedback of the execution is encouraged.

The half-squat is the most widely used exercise in the resistance training, which must be considered optimal only if it is specific and safe. Safeness relies, with other factors, in using the correct technique and being provided with adequate monitoring and feedback. In this perspective, this study a) provided a thorough characterization of the less dangerous squat technique, and b) showed how wearable inertial measurement units (IMU) can be used to quantify key variables useful to reduce errors. The IMU estimate presented a good concurrent validity (r=0.91) for trunk maximal forward inclination, although with significant mean systematic bias of 7±5 deg, and fair concurrent validity for pelvis and barbell rotations in the frontal plane with lower systematic biases. Thus the use IMUs to provide practitioners a quantitative feedback of the execution is encouraged.

The power grid is evolving into a smart grid due to the diverse energy generation and distribution. This complex grid has to be continuously monitored in real-time for its safe operation. Sensors known as phasor measurement units (PMUs) are used for obtaining health information pertaining to the grid in terms of time-synchronized voltage and current phasors. Measurements from several PMUs are sent through a synchrophasor communication network (SCN) to the phasor data concentrator (PDC). The PMUs, the PDC and the SCN together constitute the wide area measurement system (WAMS). Being an important constituent of the WAMS, the resiliency estimation of SCNs is paramount for their proper design. Resilience is a measure of the systems resistance to the disturbances or a measure of its ability to bounce back to a functional state in the event of failure. This paper presents a quantitative metric for estimating the resiliency of SCNs. Monte Carlo simulation (MCS) models are used to simulate random component failures, and the data is used for measuring the resiliency of the SCNs. A multi-objective genetic algorithm (GA) is used for optimizing the placement of PMUs and the PDC, to observe the power system with the minimum number of PMUs, and to simultaneously maximize the resilience. The practical power grid of West Bengal, India, is analyzed as a case study. This work can be a significant contribution to the power sector as it assists in the proper planning and placement of the communication infrastructure in a WAMS.

The variability and distributed nature of renewable energy sources (RES) pose challenges to real-time monitoring and control in distribution networks. Phasor measurement units (PMUs) provide high-precision, timesynchronized measurements, significantly improving state estimation (SE) accuracy in complex grids. This paper reviews SE in distribution systems using PMU data, focusing on challenges introduced by high-RES integration. Traditional techniques, such as weighted least squares (WLS), are analyzed, revealing limitations like reduced observability and accuracy due to RES intermittency. To address these challenges, advanced methods such as robust optimization, dynamic network reconfiguration, and decentralized control are explored, showing improved network reliability and adaptability under RES variability. Furthermore, innovative approaches like Bayesian non-parametric modelling are discussed, offering solutions to mitigate uncertainties and enhance grid flexibility. Case studies highlight the scalability and effectiveness of PMUs in extensive networks, showcasing their role in improving both SE precision and system stability. These findings underline the critical need for precise and integrated SE techniques to develop resilient, adaptable smart grids capable of accommodating the increasing penetration of RES, setting a foundation for future technological advancements.

System integrity protection schemes (SIPS) are schemes that can, under potentially hazardous conditions, prevent a complete blackout of endangered parts of an electrical power system (EPS). The main objective of SIPS is to monitor the state of the power transmission network in real time and to react in emergency cases. This paper explores the use of phasor measurement unit (PMU) technology for the development of SIPS as a part of wide-area monitoring, protection, and control (WAMPAC) systems. A new SIPS development method is described using the experience from the real-time operation. The developed optimal bus-splitting scheme identifies potential actions that can eliminate or reduce power system overloads and protect the integrity of the power system. An optimal bus-splitting scheme based on a DC power flow model and PMU measurements is given as an example and is explained and tested on an IEEE 14 bus test system. Conducted simulations indicate that the described SIPS methodology s...

Wearables are commonly used in practice for measuring and monitoring performance in high-level sports. That being said, they are often designed and intended for use during sports conducted on rigid surfaces. As such, sports that are conducted on sand, e.g. beach volleyball, lack equipment that can be specifically applied in the field. Therefore, the aim of this study was to develop and validate an inertial measurement unit (IMU)-based system for automatic jump detection and jump height measurement in sand. The system consists of two IMUs, which were attached to different parts of the athletes’ bodies. For validation under laboratory conditions, 20 subjects each performed five jumps on two consecutive days in a sandbox placed on force plates. Afterwards, five beach volleyball athletes performed complex combinations of beach volleyball-specific movements and jumps wearing the IMUs whilst being video recorded simultaneously. This was conducted in an ecologically valid setting to determ...

Phasor measurement units (PMUs) are important devices for protection, monitoring, and control of modern power systems. Unlike the supervisory control and data acquisition (SCADA) system which only measure the magnitude, PMUs can provide a set of synchronized phasor measurements with high sampling rate with the accuracy of less than one second, for better system monitoring especially during the outages. Since the PMUs are costly devices, system operator is not able to install a PMU at each bus to maximize the observability of system. To this end, determination of the number of PMUs in the system for having a 100% observability is pivotal. In this paper, honey bee mating optimization (HBMO) approach is utilized to allocate PMUs in modern power systems. Moreover, the impact of line outages, as well as measurement loses, are considered. The simulation results show the effectiveness of the proposed method on solving the PMU placement problem.

Today, microgrids in distribution networks are in dire need of improvement to cope with economic challenges, human losses, and equipment placement issues. Today, there is the issue of scattered resources in distribution systems, which has created many problems in the areas of environment, economy, and human and animal losses. The most important challenge in this section is the existence of voltage and frequency fluctuations during the occurrence of possible events such as severe load changes or errors in distribution networks. Having such a big problem can call a distribution network into question and destroy it. Therefore, it is necessary to provide an optimal method that can meet and cover these challenges. For this purpose, the present research deals with the problem of establishing and placing a multifunctional phasor measurement unit to improve the parallel state estimation in distribution networks, which offers a control approach. This approach determines the time of occurrenc...

In the current scenario; most of the appliances are mainly depending upon electric power for their operation, so the demand for electric power increasing day by day. Now there is a big challenge in supplying power with proper continuation and reliability to the appliances. To accept the challenge of observability of the grid in a proper way Phasor Measurement Units (PMUs) are used for real-time data collection. In recent years, there has been growing interest in synchro phasor measurements like PMUs Power systems are now being gradually populated by PMUs since they provide significant phasor information for the protection and control of power systems during normal and abnormal situations. There are several applications of PMUs, out of which state estimation is widely used. To improve the robustness of state estimation, different approaches for the placement of PMUs have been studied. This dissertation introduces two works related to PMU in them one is the strategicPMU installation approach and the second is a PMU application based fault detection, allocation and fault classification approach. Due to the high installation and operating cost of PMUs, it is required to reduce the number of PMUs.In this reference, many researchers proposed various OPP techniques which help to reduce the number of PMUs with maximum observability. After observing the OPP location with complete power system observability, it is to be seen the requirement of strategic PMU installation. In this view, many researchers strategically installed PMUs by proposing different methodologies. This dissertation tries to extend the strategic PMU installation work in a new way at already-found OPP locations. In the extension of the strategic PMU installation, this dissertation proposed a strategic approach for PMU installation in the power system. This approach has particular selection criteria for the OPP location to install PMU. The selection criteria for the selection of an OPP location to install PMU depends on two conditional parameters namely Degree of Connectivity and shortest path. Finally, the proposed approach generates a best-suited path for PMU installation that has the shortest travelled distance and particular priority of OPP locations. The proposed approach is verified with IEEE-14 and IEEE-30 bus systems and it assures complete power system observability. As we know that with the growth in the world population, the supply points are also increasing and due to which grid size also increasing. In a large size grid, there is more possibility of occurring faults or abnormalities and sometimes these faults become a cause of major power failures like a blackout. To rectify this problem it is necessary to detect the fault in the power system and also find the fault location. In early times the fault location finds in the traditional way or in other words checks the whole line and after then the fault location is obtained. This way to find the fault location is very time-consuming and sometimes becomes inaccurate. With accepting the challenges of fault detection and allocation many researchers developed various types of methodologies and also this work is pursued in present time. As we know that there is a new welcoming technology Phasor measurement unit. It can measure the magnitude and phase angle of an electrical phasor quantity like voltage or current and also provide the frequency measurement. This dissertation proposes a PMU application-based approach for fault analysis which is based on the frequency characteristic analysis of voltage and current phasor quantity. Although, ideally frequency of voltage and current are the same in the abnormal condition they may differ from each other. This difference in frequency is separately measured by PMU block at MATLAB Simulink Platform. The PMU (PLL-Based, Positive-Sequence) block is inspired by the IEEE Std. C37.118.1-2011. In this fault analysis work, we detect, allocate and identify the nature of short circuit faults in the system. The frequency characteristics analysis is done from the simulation performed on the two models. These models are created and simulated in the MATLAB Simulink environment. The proposed approach is tested on two MATLAB Simulink models and observed a satisfactory. The proposed fault analysis approach is capable to analyze short circuit faults only at source side and load side bus.

This abstract presents an iterative and multi-perspective context of use analysis approach for identifying medically relevant application scenarios and required features for a motion analysis system based on inertial motion capture technology. Different iterations of one underlying process are described and discussed. The focus is on how all participating research disciplines as well as potential users in terms of healthcare providers can be involved in this process on equal footing.

Recently, the electric power systems are operated relatively close to their operational limits due to worldwide deregulated electricity market policies. The power systems are being operated with high stress, and hence sufficient voltage stability margin is necessary to be managed to ensure secure operation of the power system. A particle swarm optimization-based support vector machine (SVM) approach for online monitoring of voltage stability has been proposed in this paper. The conventional methods for voltage stability monitoring are less accurate and highly time-consuming consequently, infeasible for online application. SVM is a powerful machine learning technique and widely used in power system to predict the voltage stability margin, but its performances depend on the selection of parameters greatly. So, the particle swarm optimization is applied to determine the parameter settings of SVM. The proposed approach uses bus voltage angle and reactive power load as the input vectors to SVM, and the output vector is the voltage stability margin index. The effectiveness of the proposed approach is tested using the IEEE 14-bus test system, IEEE 30-bus test system and the IEEE 118-bus test system. The results of the proposed PSO-SVM approach for voltage stability monitoring are compared with artificial neural networks and grid search SVM approach with same data set to prove its superiority. Particle swarm optimization (PSO) • Support vector machine (SVM) • Voltage stability margin index (VSMI) • Artificial neural networks (ANN) • Grid search (GS) Communicated by V. Loia.

Several monitoring, protection, and control applications designed for modern power grids are based on detailed grid models and thus require an accurate knowledge of line parameters. A synchronized monitoring infrastructure based on Phasor Measurement Units (PMUs) may be of great support to the task of line parameters estimation, but the accuracy of the estimated parameters may be largely affected by the uncertainty of all the elements of the PMU-based measurement chain. Thus, an accurate parameters estimation must appropriately consider the metrological behavior of all these elements, and in particular that of instrument transformers. To address this challenge, the paper proposes an enhanced multi-branch method for accurate estimation of the line parameters and of the systematic measurement errors introduced by the instrument transformers when measurements for multiple operating conditions are considered. Indeed, multiple operating conditions are dealt with properly, thanks to an in-depth analysis of the problem modeling within the framework of Tikhonov regularization. The validity of the proposed approach is confirmed by the results obtained on the IEEE 14 bus test system.

This paper proposes a new hybrid charged system search (CSS) algorithm based state estimation in radial distribution networks in fuzzy framework. The objective of the optimization problem is to minimize the weighted square of the difference between the measured and the estimated quantity. The proposed method of state estimation considers bus voltage magnitude and phase angle as state variable along with some equality and inequality constraints for state estimation in distribution networks. A rule based fuzzy inference system has been designed to control the parameters of the CSS algorithm to achieve better balance between the exploration and exploitation capability of the algorithm. The efficiency of the proposed fuzzy adaptive charged system search (FACSS) algorithm has been tested on standard IEEE 33-bus system and Indian 85-bus practical radial distribution system. The obtained results have been compared with the conventional CSS algorithm, weighted least square (WLS) algorithm and particle swarm optimization (PSO) for feasibility of the algorithm.

Recently, information is being used to enhance supporting technologies in conference management systems, which greatly improves the efficiency of conference organizing affairs and promotes extensive communication and cooperation between researchers. The on-line conferencing ba (OLCB) serves as a conference management system and provides an environment for knowledge creation. CorMap analysis is a technique for qualitative meta-synthesis, which can carry out series mining from qualitative data. The early OLCB system pushes the visualized results of CorMap analysis to users by images. In this paper, the authors introduce an interactive CorMap analysis to enhance the OLCB system, which enables users to conduct the conference mining process directly and acquire more clear and structured information. The working process of interactive CorMap analysis is shown with the application of the 7th International Workshop on Meta-synthesis and Complex Systems (MCS’2007).

This study investigates the optimum configuration of Phasor Measurement Units (PMUs) for strategic placement within power transmission networks, utilizing nonlinear programming to obtain complete power network observability and maximize the coverage of observed buses throughout the grid. To address this complex engineering problem, we first solve a 0-1 integer linear programming model. We then apply solution methods based on sequential quadratic programming and interior-point approaches in solving equivalent nonlinear programming models, incorporating a necessary and sufficient stopping criterion to ensure global optimality while avoiding the Maratos effect. Our approach avoids these infeasibility issues by leveraging a piecewise convex feasible region, permitting the optimizer solver to simultaneously satisfy both feasibility and optimality without the need for a penalty function to perform in the iterative process. This leads to the successful rejection of the Maratos effect, a crucial key factor in ensuring the accuracy and effectiveness of the optimization process without destroying the super-linear convergence close to optimality. Representative numerical results are presented, along with a discussion of optimality conditions essential for achieving the best solution. The minimization problem is solved in MATLAB in a two-stage process. Initially, an objective function with a single product is minimized to determine the number of PMUs required for wide-area monitoring, control, and state estimation. A second product is subsequently added to the objective function to maximize the observability of network buses. The optimal PMU placement set solutions are produced to give all network buses observed directly or indirectly. In order to find out globally optimal solutions, IEEE power networks are performed with the mathematical algorithms in MATLAB.

Currently, an unmanned aerial vehicle (UAV) utilizes global navigation satellite systems (GNSS) in conjunction with other modalities for localization purposes. Nevertheless, this approach faces robustness issues when GNSS signals become unavailable or sensors malfunction. Clearly, the robustness of the system increases considerably when multiple UAV agents are employed to perform collaborative positioning. In this work, an online distributed solution is proposed for relative localization, which incorporates multiple UAVs together with Signals of Opportunity (SOPs) as well as inertial, visual, and optical flow measurements. The proposed localization system includes relative self-localization of each UAV agent, as well as a reliable distributed relative positioning system (DRPS) for each UAV based on the relative positions from other UAV agents in its vicinity. The latter positioning strategy is required in case the relative self-localization fails, mainly due to such problems as inertial measurement unit (IMU) accumulated error drift, camera sensor errors, or SOP shortfalls due to multipath or antenna obstruction. Extensive field experiments validate the proposed technique and demonstrate increased localization accuracy and robustness when compared to the benchmark approach that does not include cooperation between UAVs.

This paper presents an optimal method of Phasor Measurement Unit (PMU) placement in Bowin area distribution grid of the Provincial Electricity Authority (PEA) using the Improved Greedy Method (IGM) in order to achieve a minimum number of PMUs for complete observability of all bus voltages. The proposed method introduces the criteria of bus selection for PMU placement, regarding a number of branches connected to the selected bus as well as the length of those branches. Subsequently, the mismatches of the observed voltages resulted from the proposed method are compared with those resulted from the Depth First Search (DFS) using the Power System Analysis Toolbox (PSAT) and the original Greedy method (GDY) to reveal the effectiveness of the proposed placement methods. For the DFS and GDY methods, a bus with the highest number of connected branches is initially selected as the first PMU bus. However, if there is more than one bus, the first PMU bus will be randomly selected from those qu...

The document describes the usage of an inertial measurement unit platform in a remote laboratory. The platform is based on widely used modern MEMS components, such as accelerometers and gyroscopes, in combination with digital signal processing and web technologies. Students can work on the real device from anywhere in the world. They can measure data from a real process remotely and subsequently train various signal processing techniques using this data. They can also get familiar with the properties and drawbacks of the inertial sensors used on the remotely controlled device.

In this paper we consider the problem of State Estimation (SE) in large-scale, 3-phase coupled, unbalanced distribution systems. More specifically, we address the problem of including mixed real-time measurements, synchronized and unsynchronized, from phasor measurement units and smart meters, into existing SE solutions. We propose a computationally efficient two-step method to update a prior solution using the measurements, while taking into account physical constraints caused by zero-injection buses. We test the method on a benchmark test feeder and show the effectiveness of the approach.

This study presents a new robust state estimation (SE) approach for power systems that are monitored by synchronised phasor measurements. The proposed robust SE utilises the least absolute value (LAV) of residuals to determine the system state. Although conventional deterministic LAV-based SE is robust against bad measurements, it is vulnerable with respect to the network parameters' errors. In other words, the conventional LAV-SE method is not robust against the network parameters' errors and these errors can make the SE results inaccurate. The proposed robust SE aims at solving this problem of the conventional LAV-SE. Robust optimisation, strong duality theorem, and Big-M linearisation technique have been used to construct the proposed SE approach, which is robust against the network parameters' errors. Additionally, the proposed robust SE is finally formulated as a tractable mixed-integer linear programming optimisation problem. Comprehensive numerical experiments and a probabilistic evaluation approach are presented to evaluate the effectiveness of the proposed robust SE compared to the conventional deterministic SE in the presence of the uncertainty source of network parameters' errors.

Day to day to electrical power demand increases very rapidly with linear and non-linear load demands. Especially the nonlinear loads are creating the harmonics in the current and voltage signals. The current and voltage signal values are measured with the phasor measurement unit (PMU) for the proper magnitude and phase angle calculation even in the presence of harmonic components in the signals. The performance of the PMU is depending upon the phasor calculation technique. Different technique/methods are available for the phasor calculation, from the method to method there is difference in the accuracy, phasor computation time and complexity. In this paper various techniques for phasor calculation are presented. For better performance of PMU, more accurate and less computation time for phasor calculation technique is required. But in real time, accuracy and speed both may not satisfied with single technique. Need to find a satisfactory technique, which satisfies the speed of phasor computation and accuracy. In this paper it is proposed that direct phasor estimation technique, which gives the better results in terms of accuracy and time and this method, satisfies the requirements for the dynamic monitoring of power system according to the IEEE std. C37.118.1-2011.

In the recent years the monitoring and operation of the power system became complex, due to the more demand from the different linear and non-linear loads and generation from the different sources. For the effective monitoring and operation of the power system, existing power system monitoring methods need to improve or new technologies are required. For the effective monitoring and operation of the power system phasor measurement unit (PMU) based monitoring is suitable, because it provide the dynamic state monitoring system. In this paper PMU based monitoring is proposed with effective data storage system and protection. With this method phasor values of voltage and current signals are calculated at the location of PMU and with the help of software based program effective data storage also possible. With this proposed model the phasor values in the power system at different locations monitoring also possible and required phasor data only stored and total data is only monitored. The...

This paper proposes two procedures to compute the quality of phasor estimations. These procedures will enable phasor measurement units (PMUs) to report, with each measurement, the quality of the estimated phasor. The procedures rely solely on measured data and are independent of the algorithm used to obtain the phasor estimate. These procedures were conceived by requiring a reduced number of numerical operations to make its implementation possible in microcontroller-based PMUs. Perhaps the most important contribution of this paper is the suggestion that phasor measurements should, along with the time stamp, carry information on the quality of the phasor estimation.

Distribution power networks are very complex, due to the great number nodes, short distances, and small amplitude and phase angle differences between nodes, faster dynamics and lack of standard documentation. Thus, these complexities have raised the need to develop new Phasor Measurement Unit (PMU) called Micro-Phasor Measurement Unit (µPMU) with high accuracy and high precision. In this work, several estimation techniques have been investigated so far for improving effectiveness and accuracy of this micro-PMU.

an integer linear programming based methodology for optimal placement of PMU in a given power network for full observability of that network is presented in this paper. First conventional complete observability of the given network is formulated and then, zero injection bus constraints are added in previous formulation. The results from conventional and modified formulation are than compared. Moreover minimum PMU placement problem may have multiple solutions, so to decide best one, two indices are proposed, BOI and SORI, where BOI is Bus Observability Index and SORI is System Observability Redundancy Index. Results on 9 bus, IEEE 14 bus systems are presented.

This paper discusses the details of the development of a Phasor Measurement Unit regarding the requirements of the IEEE C37.118-2005 synchrophasor standard relative to steady-state conditions on grid monitoring and control. This phasor measurement unit is intended to be used for field tests sooner.

This paper introduces a technique for 'pre-compliance' testing of Phasor Measurement Units (PMUs) against the dynamic requirements of the IEEE C37.118.1-2014 standard, which include dynamic and steady-state test scenarios. . The tests described are a necessary, but not complete, requirement for passing the IEEE standard and quickly highlight shortcomings in PMU operation during dynamic conditions. The pre-compliance test presented in this paper only requires typical relay test equipment, with little requirement for significant temporal accuracy when initiating waveform test files. The compliance test is intended to allow PMU owners to assess a device's performance before considering its use in monitoring dynamic performance. Failure of these tests can indicate the need to recalibrate or replace the PMU or find another vendor. The described method is applied to the voltage inputs of a typical commercial PMU and the results presented. The process for the creation of test waveforms is described, along with the data analysis technique used. The test waveforms and analysis source code are made available under open source licenses.

As we have adopted the concept of interconnected power system, the role of substation is become more important. Substation connects generation station to the distributor or to the end consumer via transmission system depending upon the types of substation. Activities like switching of transmission lines, parameter measurement, fault detection and storing of historical data are carried out in each of the substation premises. Earlier time this all activities was carried out manually, as complexity of system increase the role of substation become crucial and we need to move towards the use of IEDs and Automation. Activities carried out at substation can broadly classify in to three term i.e. supervision, control and Data acquisition. In an automated substation this all three will done using Programmable Logic controller and SCADA. For system monitoring or supervision data is given to controllers from RTU. Control command according to system parameter is produced by PLC and SCADA provides a human machine interference. Substation automation systems make their control and monitoring possible in real time and maximize availability, reliability and safety of the system.

The International System of Units is a widely used system of measurement standards that provide the basis for expressing physical quantities, such as the kilogram for mass. This paper will describe a proposed modernization of some of the unit definitions that would provide a system that is more stable over time and more suitable for expressing the values of many fundamental constants.

With the increasing rise of professionalism in sport, teams and coaches are looking to technology to monitor performance in both games and training to find a competitive advantage. Wheelchair court sports (wheelchair rugby, wheelchair tennis, and wheelchair basketball) are no exception, and the use of microelectromechanical systems (MEMS)-based inertial measurement unit (IMU) within this domain is one innovation researchers have employed to monitor aspects of performance. A systematic literature review was conducted which, after the exclusion criteria was applied, comprised of 16 records. These records highlighted the efficacy of IMUs in terms of device validity and accuracy. IMUs are ubiquitous, low-cost, and non-invasive. The implementation in terms of algorithms and hardware choices was evidenced as a barrier to widespread adoption. This paper, through the information collected from the systematic review, proposes a set of implementation guidelines for using IMUs for wheelchair data capture. These guidelines, through the use of flow-charts and data tables, will aid researchers in reducing the barriers to IMU implementation for propulsion assessment.

While inertial measurement units (IMU) have become an integral part of sports performance analysis, upper body-mounted IMUs have been found to exhibit poor reliability in measuring lower-limb loading. In racket sports, IMUs have been placed in a number of positions on the upper body, lower body and racket in a research setting. A potential limitation to the concurrent use of multiple IMUs is that coaches may be reluctant to allow their athletes to wear the units during training and competition due to concerns that the units would interfere with athlete movement. This study seeks to understand the perceptions of racket sports coaches towards the use of IMUs in training and competition. A total of 58 racket sport coaches responded to a survey on the use of IMUs during training and competition. Based on the responses, 96.6% (56 out of 58) of coaches indicated that they would allow their athletes to wear IMUs in training, while 65.5% (38 out of 58) would allow their athletes to wear IMUs during competition. For use in training, 9 of the 14 suggested IMU placements received significant positive responses. However, none of the suggested IMU placements received significant positive responses for use during competition and 11 of the 14 received significant negative responses. This suggests that coaches understand the benefits of collecting data from IMUs during competition there remains concern regarding inconvenience to the athlete, lack of comfort, and appearance. Despite this, for use in training, a number of upper and lower bodymounted IMUs placements have the potential to be part of regular monitoring in racket sports.

The ability to unobtrusively measure velocity in the aquatic environment is a fundamental challenge for engineers and sport scientists. In the past video systems were the first choice to monitor the athletes during training. With the acceptance of small inertial sensors new ways of investigating the athletes movements have arisen. These small systems are light, easy to use and do not hinder the athlete during training, allowing an easy tracking of training improvements. This research used a self developed low-cost inertial sensor system, attached to the lower back, to record the acceleration of swimmers performing sub-surface wall push-offs. The recorded data were downloaded to MATLAB for data analysis. Using seven swimmers, the wall push-off velocity at three different efforts was analysed and compared to a tethered cable velocity meter (criterion measure) using Regression and Bland-Altman analysis. The maximum velocity determined from the accelerometer unit was linearly related to the benchmark criteria (r 2 =0.89). A biomechanical technique for the determination of the maximum glide velocity from acceleration data has been verified.

Inertial sensors, like accelerometers and gyroscopes, are rarely used by themselves to measure displacement. Currently, the use of low cost IMUs for this particular application is very impractical due to the accumulation of errors from various sources. In this study, a position estimation using Inertial Measurement Unit (IMU) in a quadcopter is developed. The objective of the researchers is to develop an algorithm that will make the quadcopter travel a certain displacement or position. The algorithm uses mainly the information from the IMU and minimizes the error between the desired displacement and the actual displacement travelled by the quadcopter. The implemented approach is to use an error factor. The error factor is a value that is inversely proportional to the desired displacement. Experiments indicate that the system provides accurate pose estimates and are robust.

In developing countries, the awareness and development of Smart Grids are still in the introductory stage and their full realisation requires significantly more time and effort. In addition, some developing countries introduced partial Smart Grids, which are inefficient, unreliable, and environmentally unfriendly. The logical tools, control, and optimisation processes necessitate dependable computation servers for selfrecovery, fault lenient, demand-management, and optimal power flow features. The engagement of Cloud Computing satisfies the requisite of data management and computing for Smart Grid applications. This research attempts to introduce a costeffective wireless communication technology suitable for Smart Grids to facilitate data dissemination and querying effectively with the Cloud control. The Cloud is the link between the energy providers and the consumers to exchange data and to deliver the decisions of the energy providers to the consumers through this probable communication technology. To enhance the performance of a Smart Grid in terms of minimising the unit cost of electricity generation, successful integration of renewable energy resources, energy supplier-consumer two-way communication facilities, and environmental friendliness, this research aims to develop power dispatching algorithms incorporating economic and environmental protocols. The algorithms are based on an analytical approach that provides solutions at a faster rate compared to the time-consuming and laborious iterative techniques. Cloud Computing strategies will be adapted for instantaneous data collection, execution of dispatching algorithms, and provision of two-way communications. The efficacy of the proposed on-line power dispatching algorithms with Cloud services will be determined applying the IEEE test systems and an Indian 62-bus power system incorporating Smart Grid technologies. Finally, a Smart Grid Admin Dashboard and a Smartphone App will be developed for managing the Smart Grid for end-users. These tools will facilitate the transmission to end-users of all the energy-related information transparently on concurrent basis and allow better planning for any upcoming events in an economical manner, which in turn helps the Smart Grid in generation-demand management.

The occurrence of light spinal diseases due to the low physical activity of daily life is continuously increasing. Recovering form these diseases requires specific and directed physical activity and can conveniently performed in swimming pools where the apparent weight reduction due to the water helps letting patients perform the relief movements. Unfortunately a way for easily assessing the correctness of the patient's movement is still missing and in most cases everything relies on the capabilities of the trainers, which must be continuously present. This paper describes an attempt to arrange a simple system suitable for a quasi on-line self assessing to the movement correctness. The proposed system is based on two inertial assemblies to be worn on the wrists and capable of sending data to a receiver installed at pool border. Data received from these small assemblies are processed to show the patients the symmetry of their movements, which is connected to the movement efficiency. The inertial assemblies are arranged by using a commercial miniaturized Inertial Measurement Unit, a Teensyduino board, and a µP anel WiFi transmitter which is able to send the data to the received during the swimming. The receiver process the data in-line so that, when the patients stop swimming to take a rest, they can be displayed to the patients as a self-assess of the just performed activity.

The occurrence of light spinal diseases due to the low physical activity of daily life is continuously increasing. Recovering form these diseases requires specific and directed physical activity and can conveniently performed in swimming pools where the apparent weight reduction due to the water helps letting patients perform the relief movements. Unfortunately a way for easily assessing the correctness of the patient's movement is still missing and in most cases everything relies on the capabilities of the trainers, which must be continuously present. This paper describes an attempt to arrange a simple system suitable for a quasi on-line self assessing to the movement correctness. The proposed system is based on two inertial assemblies to be worn on the wrists and capable of sending data to a receiver installed at pool border. Data received from these small assemblies are processed to show the patients the symmetry of their movements, which is connected to the movement efficiency. The inertial assemblies are arranged by using a commercial miniaturized Inertial Measurement Unit, a Teensyduino board, and a µP anel WiFi transmitter which is able to send the data to the received during the swimming. The receiver process the data in-line so that, when the patients stop swimming to take a rest, they can be displayed to the patients as a self-assess of the just performed activity.

The paper presents the implementation details and the experimental validation of a linear state estimator based on synchrophasor measurements in a real subtransmission network. The data are provided by 15 phasor measurement units (PMUs) installed in the 125-kV grid of the city of Lausanne, Switzerland. The PMU-based monitoring infrastructure, the telecommunication and the phasor data concentrator are described in detail. We compare the performance of two different state estimation methods, i.e., the linear weighted least squares and the least absolute value estimator, with a focus on the influence of the line parameter errors on the state estimates. We further analyze the latency contribution associated to each step of the measurement chain, in order to validate its appropriateness to serve timecritical power system applications.

The invention of Phasor Measurement Units (PMUs) produce synchronized phasor measurements with high resolution real time monitoring and control of power system in smart grids that make possible. PMUs are used in transmitting data to Phasor Data Concentrators (PDC) placed in control centers for monitoring purpose. A primary concern of system operators in control centers is maintaining safe and efficient operation of the power grid. This can be achieved by continuous monitoring of the PMU data that contains both normal and abnormal data. The normal data indicates the normal behavior of the grid whereas the abnormal data indicates fault or abnormal conditions in power grid. As a result, detecting anomalies/abnormal conditions in the fast flowing PMU data that reflects the status of the power system is critical. A novel methodology for detecting and categorizing abnormalities in streaming PMU data is presented in this paper. The proposed method consists of three modules namely, offline Gaussian Mixture Model (GMM), online GMM for identifying anomalies and clustering ensemble model for classifying the anomalies. The significant features of the proposed method are detecting anomalies while taking into account of multivariate nature of the PMU dataset, adapting to concept drift in the flowing PMU data without retraining the existing model unnecessarily and classifying the anomalies. The proposed model is implemented in Python and the testing results prove that the proposed model is well suited for detection and classification of anomalies on the fly.

We examine the relation between two devices used in measuring the timing in lower limb complex movement tests for DanceSport athletes, an inertial measurement unit (IMU) and a FitLight Trainer device, with the latter regarded as the gold standard method in the field. Four tests are selected to cover the lower limb movements. The research sample comprises 21 experienced dancers from different dance disciplines, performing the four tests with each of their lower limbs. Compared using concurrent validity, the two devices used show great agreement for estimating the total tests’ run times, with interclass correlation coefficients between 0.967 and 0.994 for all tests. This agreement is additionally confirmed by Bland–Altman plots. As an alternative to other devices, the IMU sensor has proven to be a precise and suitable device for measuring timing and testing in sports. Its mobility, light weight, and size are advantages of this device in addition to measurement accuracy.