Traceability and global recognition of measurement values and its impact and economic importance in the era of smart grid (original) (raw)
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Measurement Infrastructure to Support the Reliable Operation of Smart Electrical Grids
IEEE Transactions on Instrumentation and Measurement, 2015
Grid operators are facing a significant challenge in ensuring continuity and quality of electricity supply, while more and more renewable energy sources are connected to the grid. The resulting evolvement of so-called smart grids strongly relies on the availability of reliable measurement data for monitoring and control of these grids. This paper presents an overview of the results achieved in recent smart grid metrology research in Europe, aiming to realize the required metrology infrastructure for ensuring security and quality of supply in future smart electrical grids. A consortium of 22 metrology and research institutes has made significant steps in modeling of smart grids, enhancement of the revenue metering infrastructure, performance and evaluation of onsite power quality campaigns, and the development of a metrological framework for traceability of smart grid phasor measurements.
Importance of Measurements in Smart Grid
The need to get reliable supply, independence from fossil fuels, and capability to provide clean energy at a fixed and lower cost, the existing power grid structure is transforming into Smart Grid. The development of a smart energy distribution grid is a current goal of many nations. A Smart Grid should have new capabilities such as self-healing, high reliability, energy management, and real-time pricing. This new era of smart future grid will lead to major changes in existing technologies at generation, transmission and distribution levels. The incorporation of renewable energy resources and distribution generators in the existing grid will increase the complexity, optimization problems and instability of the system. This will lead to a paradigm shift in the instrumentation and control requirements for Smart Grids for high quality, stable and reliable electricity supply of power. The monitoring of the grid system state and stability relies on the availability of reliable measurement of data. In this paper the measurement areas that highlight new measurement challenges, development of the Smart Meters and the critical parameters of electric energy to be monitored for improving the reliability of power systems has been discussed.
On the remote calibration of electrical energy meters
The measurement of the electrical energy and its billing for tax purpose are of great relevance. In spite of its importance, in the past a scarce attention was given to issues as the calibration and the traceability of the electrical energy meters, so that, at least in Italy, more than 30 millions of energy meters operate and put a tariff without proper metrological characterization. This situation is caused by both the absence of specific laws and the high cost related to the traceability process. In this ambit, a new European Directive on measuring instruments (MID) was introduced in 2004 with the aim of providing a high level of metrological protection in order that any party affected can have confidence in the result of measurement. In Italy the MID was adopted by a legislative decree and imposed that: (i) each active electrical energy meter put into service has to be kept in test for a period for verifying its operating; (ii) after the test period, with positive result, the meter has to be calibrated at least twice in the year. The paper proposes a discussion about the issues of active electrical energy meter calibration and the analysis of requirements of the MID. Finally, the design of a device that may solve the problem of the traceability to national standards in easy and economic way is reported.
Smart grid measurement uncertainty: Definitional and influence quantity considerations
2018 First International Colloquium on Smart Grid Metrology (SmaGriMet), 2018
Measurement uncertainty, in general terms, is an expression of the quality of a measurement. It is typically quantified by defining the location and spread of the distribution of a hypothetical infinitely large number of measurements of the thing being measured. The Guide to the Expression of Uncertainty in Measurement (GUM) classifies uncertainties according to whether they are evaluated by statistical means or not. The GUM also mentions that an incomplete definition of the measurand can give rise to large uncertainty in the result. For some of the quantities measured in the Smart Grid, it may be that this "definitional uncertainty" could be a major source of problems. Influence quantities may have a bearing on the result of a measurement without being the subject of the measurement. For example, signal harmonics, noise and temperature effects, while not desired as part of a measurement, exist in power system signals being measured, and they have (sometimes significant) effects on the measurement process.
Measurements infrastructure — futurological considerations
Measurements infrastructure
Futurology as science for predicting humanity progress is important for planning specific steps to be taken today. Author made an attempt of scientific prediction concerning development of such important measurement infrastructure components as comparisons of measurement standards, interlaboratory comparisons of measurement results and calibration. Current state of this measurement infrastructure component should be improved to meet the challenges of a complicated and changeable environment. Comparisons of measurement standards are not performed often. Number of participants is limited. CMCs are difficult to obtain. Interlaboratory comparisons and calibrations are separated from comparisons, etc. Idea of measurement infrastructure future improvement is substantiated. Global informatization provides advantages and opportunities for it. The answer to modern challenges is seen in the creation of the Comprehensive Measurement Traceability Network (hereinafter — the Network). The Network...
ACTA IMEKO, 2014
In the paper the current state and the establishment of metrology infrastructure and traceability of the measurements of electrical power and energy, i.e. the creation of conditions for unity of power and energy measurements, international comparability of the results and measurements which insure fair trade and consumers' protection are elaborated. Beside the legal, also other aspects are discussed, like the needs for calibration and verification in the field of electrical power and energy, participants in the chain of measurements and trade with electrical energy, the organization, the infrastructure, the methods and the systems of calibration and verification. An organization and certain documents which will contribute to the establishment of a system in accordance with the international standards and practice, as well as traceability and fair trade, are proposed.
Next Generation Real-Time Smart Meters for ICT Based Assessment of Grid Data Inconsistencies
Energies
The latest technological developments are challenging for finding new solutions to mitigate the massive integration of renewable-based electricity generation in the electrical networks and to support new and dynamic energy and ancillary services markets. Smart meters have become ubiquitous equipment in the low voltage grid, enabled by the decision made in many countries to support massive deployments. The smart meter is the only equipment mandatory to be mounted when supplying a grid connected user, as it primarily has the function to measure delivered and/or produced energy on its common coupling point with the network, as technical and legal support for billing. Active distribution networks need new functionalities, to cope with the bidirectional energy flow behaviour of the grid, and many smart grid requirements need to be implemented in the near future. However there is no real coupling between smart metering systems and smart grids, as there is not yet a synergy using the opportunity of the high deployment level in smart metering. The paper presents a new approach for managing the smart metering and smart grid orchestration by presenting a new general design based on an unbundled smart meter (USM) concept, labelled as next generation open real-time smart meters (NORM), for integrating the smart meter, phasor measurement unit (PMU) and cyber-security through an enhanced smart metering gateway (SMG). NORM is intended to be deployed everywhere at the prosumer's interface to the grid, as it is usually now done with the standard meter. Furthermore, rich data acquired from NORM is used to demonstrate the potential of assessing grid data inconsistencies at a higher level, as function to be deployed in distribution security monitoring centers, to address the higher level cyber-security threats, such as false data injections and to allow secure grid operations and complex market activities at the same time. The measures are considering only non-sensitive data from a privacy perspective, and is therefore able to be applied everywhere in the grid, down to the end-customer level, where a citizen's personal data protection is an important aspect.
Software evaluation of smart meters within a Legal Metrology perspective: A Brazilian case
2010 IEEE PES Innovative Smart Grid Technologies Conference Europe (ISGT Europe), 2010
Induced by a very unfavorable scenario of nontechnical losses (electricity theft), some electrical distribution companies in Brazil have moved from the traditional one meter per residence measurement process to a centralized multiresidences meter with two-way communication features, enabling both automatic reads and remote connect/disconnect of energy supplies. Those improvements can be seen as a natural transition toward an effective Smart grid, and have brought together the needs of a deep revision on regulatory procedures for the electrical meters evaluation conducted by the Brazilian Metrology Office. This paper shows that the increasing complexity from those new electrical grid equipments, particularly conveyed by additional software procedures, is a major issue and needs to be rapidly assimilated by metrological controls to avoid the appearance of stepping stones in the smart grid pathway. This paper aims to describe the whole set of relevant aspects revealed in this particular Brazilian experience, discussing the real scene and the respective challenges opposed.
Management of reference measurement standards as part of Smart Metrology: Gauge Blocks
18th International Congress of Metrology, 2017
The question of traceability of measurement standards used for calibration is a crucial one. Optimized or not, calendar periodicity is one of the accepted pillars of quality in measurement standard verification. Aware that this practice by itself cannot guarantee the metrological performance of measurement standards, laboratories make a point of also resorting to monitoring. In fact, calibrating independent and diverse instrumentation should of itself provide the means to detect problems with the reference gauges. Indeed, there is no logical reason why a collection of independent measurement instrumentation should, on average, have a common bias. If such a bias were observed, it would most likely point to a bias in the reference gauge used for the calibrations. In this paper, this argument is investigated with reference to a practical example of gauge block calibration.
Ensuring uniformity of measurements in the European Metrology Cloud
Ukraïnsʹkij metrologìčnij žurnal, 2024
The main requirements for the calibration of measuring channels of distributed measuring instruments at the operation site are described. When preparing for calibration, the use of portable discharge working measurement standards, which consist of a reference voltage source and a divider, is substantiated. The proposed structure of the device for calibration is based on a divider of single-nominal resistors and corresponding algorithms for processing the conversion results. The feasibility of using a divider in which the resistors are closed in a ring is substantiated. To ensure the invariance to residual parameters of switching elements when implementing several evenly spaced calibration points in the conversion range, a potential-current switching of both the input reference voltage and the output converted voltage is proposed. In addition, a method to correct the equivalent additive error component of the entire measuring channel during its calibration is proposed. The expediency of the studied measuring channels to obtain intermediate conversion results is shown. An algorithm and method of processing intermediate conversion results to obtain code values at all calibration points are proposed. To process these results, it is advisable to apply an additional software in the European Metrology Cloud. It is shown that the calibration error of the measuring channels at the operation site is determined by the error of the reference voltage source.