Processing techniques for metrological improvement of low-cost smart meter hardware solution for IEC 61000-4-7 Class I harmonics measurements

The work investigates the feasibility of harmonic analysis implementation on smart meter microcontroller devices, according to IEC 61000-4-30 Class A and IEC 61000-4-7 Class I requirements. The final aim was to evaluate to what extent Class I harmonic analysis can be integrated into existing low-cost hardware platforms for smart metering, which normally have limited hardware features, especially concerning the ADC and the possibility of varying the sampling frequency with high resolution, according to the power system signal frequency. An extended experimental characterization is carried out on a case study device, aimed at analyzing its performances in terms of both measurement accuracy and computational burden. To increase metrological ADC behavior and decrease computational costs, sampling strategies and optimized interpolation algorithm have been implemented and tested verifying the feasibility of harmonic analysis implementation on smart meter microcontroller devices, according to IEC 61000-4-30 Class A and IEC 61000-4-7 Class I requirements

DEVELOPMENT AND CHARACTERIZATION OF ADVANCED METERING AND ICT SOLUTIONS FOR SMART ENERGY DISTRICTS

Climate change will have an influence on the world's 8 billion inhabitants, the majority of whom live in cities, which account for roughly two-thirds of the CO2 emissions that are at the root of the climate crisis. To attain a net-zero carbon future, a rapid transition across business models and policy is required. At the same time, policy and legislation are struggling to keep up with smart technology and the Internet of Things. The management of smart urban infrastructure is the key to successful decarbonisation and the achievement of sustainable cities. In this framework, the smart electricity infrastructure shall be equipped with integrated technologies, such solar panels, storage facilities, electric vehicle charging, intelligent public lighting system and sensor connected to a digital platform. This paradigm has changed the view of the power system itself, as decades ago the energy infrastructure was built for a centralised power system, not for a decentralised and digitalized system when energy flows in a bi-directional way within the grid. This increases the advanced metering and ICT solutions for a proper and safe management of the grid itself. This Ph.D. thesis proposes a smart architecture, as well as smart equipment and solutions, to suit the needs of the new power grid that will support smart energy districts. The developed architecture provides a distributed measurement system to keep the distributor updated about the status of the grid. Power Line Communication (PLC) has been chosen as communication technology in order to allow the DSO to reduce the cost of the upgrade of the grid and keep the control over the communication medium. Within this architecture, several devices have been developed. In detail, a concentrator and a remote PLC bridge implementing the PLC-PRIME v1.4 protocol have been developed to fulfil the requirements of the architecture. An IEC-6100-4-3/4-7 Class S Power quality analyser has been implemented on a low cost STMicroelectronics platform already used for smart metering applications. Starting from field measurement data collection, a specific software has been developed as oracle for the SCADA system in order to provide Distribution System Operators (DSOs) with valuable information for a better management of the power grid

Measurement uncertainty impact on simplified load flow analysis in MV smart grids

This work is focused on the measurement uncertainty impact on load flow analysis in medium voltage (MV) distribution networks. In more detail, the paper presents the uncertainty evaluation of a simplified load flow algorithm, which is based on the load power measurements at each secondary substation and one voltage measurement at the slack bus (i.e. the voltage at the MV bus bars of the primary substation). To reduce the costs of the monitoring system, the load flow algorithm makes use of LV load power measurements for all the substations except those of MV users, where MV transducers are usually already installed. The uncertainties on the algorithm input quantities (load powers and slack bus voltage) are calculated, considering the actual values of the loads power factors and currents and the accuracy specifications of the measurement instruments installed in the distribution network. Starting from the input quantities uncertainties, the power flows uncertainties are obtained applying the Monte Carlo analysis. The analysis is carried out on a real test system, i.e. the distribution network of Favignana Island. The compatibility is also shown between the algorithm power flow estimations and the power measurements

Uncertainty evaluation in load flow analysis: real MV distribution networks case studies

This work investigates the measurement uncertainty impact on load flow analysis in medium voltage (MV) distribution networks. The considered algorithm is a simplified load flow algorithm (LFA), developed by authors, which is based on the load power measurements at each secondary substation and one voltage measurement at the slack bus (i.e. the voltage at the MV bus bars of the primary substation). In the viewpoint of a real implementation, to reduce monitoring system costs, the LFA makes use of low voltage (LV) load power measurements for all the substations except those of MV users, where MV transducers are usually already installed. The uncertainties on LFA input quantities (load powers and slack bus voltage) are calculated, considering actual values of loads powers and currents and the accuracy specifications of measurement instruments installed in distribution network. Starting from this, power flows uncertainties are obtained applying a Monte Carlo analysis. The analysis has been carried out for real case studies; i.e. the distribution networks of Favignana and Ustica Islands. The following results refer to the Favignana case

An innovative power line communication solution for medium voltage smart grids applications

This paper summarizes the authors research activity concerning the design, modeling and experimental characterization of a new coupling system for medium voltage (MV) narrow band power line communications (NB-PLC). The proposed solution has been patented by authors and it exploits the capacitive divider of voltage detecting systems (VDSs) normally used to reveal the mains voltage presence, thus avoiding the use of dedicated MV couplers. In the following, the modeling of the VDS capacitive divider is presented and the interface card design is described, based on simulation of the whole PLC transmission channel. Laboratory tests are also presented. Finally, the results are shown of an on-field measurement campaign, which has been carried out the MV distribution networks of the Islands of Ustica and Favignana. Transmission tests demonstrate that the proposed VDS coupling system can be effective for narrowband modulated signal transmission

Feasibility of IEC 61000-4-7 Class I Gapless Implementation of Harmonics Measurement on Low-Cost Microcontroller Device

This paper presents the implementation of gapless harmonic analysis on a commercial microcontroller device, according to IEC 61000-4-30 Class A and IEC 61000-4-7 Class I requirements. The final aim is to investigate the feasibility of accurate power quality (PQ) measurements with low-cost metering platforms, to enable the capillary diffusion of PQ monitoring for smart grids applications, including distributed generation, loads, electric vehicles and so on. Signal sampling and processing have been implemented on a commercial board used as case study. Experimental tests have been carried out to verify the feasibility of gapless harmonic analysis according to Standards requirements, in terms of both measurement times and accuracy

A new low cost power line communication solution for smart grid monitoring and management

Modern smart grids require the improvement of measurement and communication infrastructures of distribution networks, at both medium voltage (MV) and low voltage (LV) levels. Distributed sensing and measurement systems are needed to provide all necessary data for grid monitoring, control and management, as well as for the implementation of a number of smart functionalities, such as remote control of distributed generators (DGs), real time analysis of power flows, automatic meter reading (AMR), demand side management (DSM), grid automation and so on [1]-[6]. Acquired network data include typical electrical network quantities and status variables (such as powers, voltages, currents, switches status, DGs power production, and remote commands) and also environmental and other parameters (temperatures, security or safety warning signals, etc.)

UNCERTAINTY ANALYSIS OF POWER RATIO PARAMETERS FOR HARMONIC EMISSION ASSESSMENT IN POWER SYSTEMS

To promote regulation strategies and incentives for harmonic mitigation, simple tools are needed for evaluating harmonic pollution levels at point of common coupling (PCC), as well as on the whole grid. Starting from IEEE Std. 1459-2010 approach [1] and the common concept of power factor correction, in [2] the authors have presented a preliminary study, aimed at investigating the possibility of using power ratio parameters for harmonic emission assessment. Being the formulation of IEEE Std. 1459 power quantities and related power ratio indicators very simple, the proposed indicators measurement can be easily integrated in common measurement instruments, thus allowing easily the assessment of harmonic emissions and related billing/incentives strategies implementation. In this context, it is important to investigate the measurement uncertainty impact on the evaluation of considered power ratios (both those defined in IEEE Std. 1459 and the new proposed ones) [2]. To this aim, the measurement of the considered parameters has been implemented on a PC-based sampling wattmeter. Starting from the instrumentation accuracies and the correlation analysis, combined standard uncertainties of power ratio indicators have been evaluated and a comparison has been made between IEEE Std. 1459 indicators and the newly proposed ones

Modelling and Performance Analysis of an Autonomous Marine Vehicle Powered by a Fuel Cell Hybrid Powertrain

This paper describes the implementation of a hydrogen-based system for an autonomous surface vehicle in an effort to reduce environmental impact and increase driving range. In a suitable computational environment, the dynamic electrical model of the entire hybrid powertrain, consisting of a proton exchange membrane fuel cell, a hydrogen metal hydride storage system, a lithium battery, two brushless DC motors, and two control subsystems, is implemented. The developed calculation tool is used to perform the dynamic analysis of the hybrid propulsion system during four different operating journeys, investigating the performance achieved to examine the obtained performance, determine the feasibility of the work runs and highlight the critical points. During the trips, the engine shows fluctuating performance trends while the energy consumption reaches 1087 Wh for the fuel cell (corresponding to 71 g of hydrogen) and 370 Wh for the battery, consuming almost all the energy stored on board