METER INSTALLATION SPECIFICATIONS HANDBOOK

This booklet is provided to assist customers, architects, engineers, contractors, developers, electricians and inspectors in planning and installing electric distribution and electric service. These regulations and policies will serve to provide safety and expedite service connection by establishing uniform and equitable standards for electric service.

Evaluación técnica y económica para analizar la viabilidad del montacargas eléctrico en el sector productivo

Esta tesis pretende demostrar y describir las diferentes características de los montacargas que existen en el mercado, teniendo en cuenta sus ventajas y desventajas, logrando como objetivo analizar la viabilidad de la implementación de los montacargas eléctricos en la industria colombiana a partir de la información brindada sobre las características esenciales de los montacargas eléctricos que hay en el mercado. Así mismo, se quiere mostrar que los montacargas eléctricos generan un ahorro sustancial en comparación con los montacargas convencionales que hay hoy en día en el mercado, logrando así que la industria colombiana reduzca sus gastos en un porcentaje mediante la implementación de las nuevas referencias de montacargas eléctricos los cuales serian una alternativa para las compañías colombianas. Mediante una detallada revisión conceptual, se mostrara la viabilidad de los montacargas eléctricos frente a los otros tipos de montacargas, teniendo como premisa el conocimiento de lo que hoy en día requieren las industrias colombianas, y cumpliendo así con una detallada comparación en donde se enfatice la diferenciación de los montacargas eléctricos con otros tipos que existen y se logre brindar una clara percepción de estos junto con las ventajas de estos vehículos para lograr así brindar mayor información a la industria colombiana sobre las ventajas de la implementación de los montacargas eléctricos en la industria colombiana.

A fuzzy clustering approach to a demand response model

This paper proposes a novel demand response model using a fuzzy subtractive cluster approach. The model development provides support to domestic consumer decisions on controllable loads management, considering consumers’ consumption needs and the appropriate load shape or rescheduling in order to achieve possible economic benefits. The model based on fuzzy subtractive clustering method considers clusters of domestic consumption covering an adequate consumption range. Analysis of different scenarios is presented considering available electric power and electric energy prices. Simulation results are presented and conclusions of the proposed demand response model are discussed.

A fuzzy clustering approach to a demand response model

This paper proposes a novel demand response model using a fuzzy subtractive cluster approach. The model development provides support to domestic consumer decisions on controllable loads management, considering consumers’ consumption needs and the appropriate load shape or rescheduling in order to achieve possible economic benefits. The model based on fuzzy subtractive clustering method considers clusters of domestic consumption covering an adequate consumption range. Analysis of different scenarios is presented considering available electric power and electric energy prices. Simulation results are presented and conclusions of the proposed demand response model are discussed.

Innovative strategies for the mitigation of acrylamide content in different food products

Acrylamide (AA) is an undesirable food toxic compound, classified as 'probably carcinogenic to humans' by the International Agency for Research on Cancer due to its toxic effects, including neurotoxicity, genotoxicity, carcinogenicity and reproductive toxicity. AA is mainly formed during the heat treatment of foods (> 120 °C) by the Maillard reaction, an essential reaction that also allows the desired levels of shelf-life and sensory properties of various food products to be achieved. Over the years, authorities and regulations have become more restrictive regarding the maximum levels of AA permitted in foods and beverages. The latest Commission Regulation (EU) 2017/2158 contains reference levels and measures to reduce AA in several food groups that contribute to the highest dietary intake, making necessary the study of promising AA mitigation strategies. The aim of this PhD research project was to identify, characterise and optimise some AA mitigation strategies in the most at-risk widely consumed foods such as potato, coffee and bakery products. Some AA control strategies were selected and investigated for each food category, also considering the main quality characteristics of the final products. The comprehensive results obtained during the three years of research activity have allowed a deeper knowledge of the traditional and innovative AA mitigation strategies, which can be extremely useful for both the food industry and international authorities. The most promising strategies studied in terms of reduction of AA while maintaining the main quality characteristics of the examined foods were: the application of pulsed electric fields and yeast immersion as pre-treatments of chips for frying; the selection of high roasting degrees for coffee products; the selection of static baking conditions for biscuits; the optimisation of alternative biscuit’ formulations by both the use of chickpea legume flour and of flour from bean with intact cotyledon cell walls.

Application of the Extended Kalman filter for speed sensorless control of PM synchronous machines

The increasing interest in the decarbonization process led to a rapidly growing trend of electrification strategies in the automotive industry. In particular, OEMs are pushing towards the development and production of efficient electric vehicles. Moreover, research on electric motors and their control are exploding in popularity. The increase of computational power in embedded control hardware is allowing the development of new control algorithm, such as sensorless control strategy. Such control strategy allows the reduction of the number of sensors, which implies reduced costs and increased system reliability. The thesis objective is to realize a sensorless control for high-performance automotive motors. Several algorithms for rotor angle observers are implemented in the MATLAB and Simulink environment, with emphasis on the Kalman observer. One of the Kalman algorithms already available in the literature has been selected, implemented and benchmarked, with emphasis on its comparison with the Sliding Mode observer. Different models characterized by increasing levels of complexity are simulated. A simplified synchronous motor with ”constant parameters”, controlled by an ideal inverter is first analyzed; followed by a complete model defined by real motor maps, and controlled by a switching inverter. Finally, it was possible to test the developed algorithm on a real electric motor mounted on a test bench. A wide range of different electric motors have been simulated, which led to an exhaustive review of the sensorless control algorithm. The final results underline the capability of the Kalman observer to effectively control the motor on a real test bench.

Compliance verification of virtual Phasor Measuring Unit using Ip-DFT algorithm according to the IEEE-60255-118-1(2018).

With the increase in load demand for various sectors, protection and safety of the network are key factors that have to be taken into consideration over the electric grid and distribution network. A phasor Measuring unit is an Intelligent electronics device that collects the data in the form of a real-time synchrophasor with a precise time tag using GPS (Global positioning system) and transfers the data to the grid command to monitor and assess the data. The measurements made by PMU have to be very precise to protect the relays and measuring equipment according to the IEEE 60255-118-1(2018). As a device PMU is very expensive to research and develop new functionalities there is a need to find an alternative to working with. Hence many open source virtual libraries are available to replicate the exact function of PMU in the virtual environment(Software) to continue the research on multiple objectives, providing the very least error results when verified. In this thesis, I executed performance and compliance verification of the virtual PMU which was developed using the I-DFT (Interpolated Discrete Fourier transforms) C-class algorithm in MATLAB. In this thesis, a test environment has been developed in MATLAB and tested the virtually developed PMU on both steady state and dynamic state for verifying the latest standard compliance(IEEE-60255-118-1).

Enhancing the reliability of electric transportation motors through insulation coordination and improved qualification

The ambitious goals of increasing the efficiency, performance and power densities of transportation drives cannot be met with compromises in the motor reliability. For the insulation specialists the challenge will be critical as the use of wide-bandgap converters (WBG, based on SiC and GaN switches) and the higher operating voltages expected for the next generation drives will enhance the electrical stresses to unprecedented levels. It is expected for the DC bus in aircrafts to reach 800 V (split +/-400 V) and beyond, driven by the urban air mobility sector and the need for electrification of electro-mechanical/electro-hydraulic actuators (an essential part of the "More Electric Aircraft" concept). Simultaneously the DC bus in electric vehicles (EV) traction motors is anticipated to increase up to 1200 V very soon. The electrical insulation system is one of the most delicate part of the machine in terms of failure probability. In particular, the appearance of partial discharges (PD) is disruptive on the reliability of the drive, especially under fast repetitive transients. Extensive experimental activity has been performed to extend the body of knowledge on PD inception, endurance under PD activity, and explore and identify new phenomena undermining the reliability. The focus has been concentrated on the impact of the WGB-converter produced waveforms and the environmental conditions typical of the aeronautical sector on insulation models. Particular effort was put in the analysis at the reduced pressures typical of aircraft cruise altitude operation. The results obtained, after a critical discussion, have been used to suggest a coordination between the insulation PD inception voltage with the converter stresses and to propose an improved qualification procedure based on the existing IEC 60034-18-41 standard.

Electrical ageing studies of polymeric insulation for power cables (estudo do envelhecimento eléctrico do isolante polimérico de cabos eléctricos

Dissertação apresentada para obtenção do Grau de Doutor em Engenharia Física - Física Aplicada pela Universidade Nova de Lisboa, Faculdade de Ciências e Tecnologia

Analysis and detection of partial discharges in an electric motor of a hybrid supercar.

The objective of this thesis was the development of a new detection method of partial discharge (PD) activity in the stator of an electrical hybrid supercar fed by a silicon carbide converter, for which detection with common methods make it very difficult to separate PD pulses from switching noise. This work focused on the analysis and detection of partial discharges making use of an antenna, a peak detector, and an oscilloscope capable of capturing the electromagnetic pulses emitted during PD activity. Validation of the proposed method was done by comparing the partial discharge inception voltage (PDIV) detected by this system with the one obtained from an optical method of proven accuracy, with different rise times and samples. Further development of this method, if proved successful on a full stator, can help increasing the overall reliability of the car, potentially allowing for real time detection of PD activity and predictive maintenance before failure of the insulation system in a hybrid vehicle.

Physical modeling and numerical simulations of degradation mechanisms in devices and insulators for power applications

In this thesis, a TCAD approach for the investigation of charge transport in amorphous silicon dioxide is presented for the first time. The proposed approach is used to investigate high-voltage silicon oxide thick TEOS capacitors embedded in the back-end inter-level dielectric layers for galvanic insulation applications. In the first part of this thesis, a detailed review of the main physical and chemical properties of silicon dioxide and the main physical models for the description of charge transport in insulators are presented. In the second part, the characterization of high-voltage MIM structures at different high-field stress conditions up to the breakdown is presented. The main physical mechanisms responsible of the observed results are then discussed in details. The third part is dedicated to the implementation of a TCAD approach capable of describing charge transport in silicon dioxide layers in order to gain insight into the microscopic physical mechanisms responsible of the leakage current in MIM structures. In particular, I investigated and modeled the role of charge injection at contacts and charge build-up due to trapping and de-trapping mechanisms in the oxide layer to the purpose of understanding its behavior under DC and AC stress conditions. In addition, oxide breakdown due to impact-ionization of carriers has been taken into account in order to have a complete representation of the oxide behavior at very high fields. Numerical simulations have been compared against experiments to quantitatively validate the proposed approach. In the last part of the thesis, the proposed approach has been applied to simulate the breakdown in realistic structures under different stress conditions. The TCAD tool has been used to carry out a detailed analysis of the most relevant physical quantities, in order to gain a detailed understanding on the main mechanisms responsible for breakdown and guide design optimization.

Cytogenetic characterization of the strongly electric Amazonian eel, Electrophorus electricus (Teleostei, Gymnotiformes), from the Brazilian rivers Amazon and Araguaia

A karyotype analysis of the electric eel, Electrophorus electricus (Teleostei, Gymnotiformes), a strongly electric fish from northern South America, is presented. Two female specimens were analyzed, one from the Amazon River and one from the Araguaia River. The specimens had a chromosomal number of 2n = 52 (42M-SM + 10A). C-bands were present in a centromeric and pericentromeric position on part of the chromosomes; some interstitial C-bands were also present. Heteromorphic nucleolus organizer regions (NORs) were detected in two chromosome pairs of the specimen from the Amazon River. The chromosome number and karyotype characteristics are similar to those of other Gymnotidae species. The genera Electrophorus and Gymnotus are positioned as the basal lineages in the Gymnotiformes phylogeny.

Using of the residues and wood composites for production of an electric guitar

The residues generation is a quite serious problem in several industrial areas and also in the lumbering area. The search for the elimination or reduction of the volume of generated residues is endless, however limited, resulting in the search for a proper destination or better use, instead of simply burning it. A lot of uses and services are commonly proposed, but with low aggregated value to the residue. This work shows the usage viability of different discarded residues and wood composites in the production of an electric guitar. Cupiuba, ipe and jatoba residues have been used besides wood composites of pinus. The residues and wood composites have shown appropriate resistance, surfacing quality and design terms, and could be used to substitute the traditionally wood used in the production of the instrument as well as in other products of similar characteristics and with larger aggregated value.

Mechanical strength evaluation for Nd-YAG laser and electric resistance spot weld (ERSW) joint under multiaxial loading

This work presents a comparison between laser weld (LBW) and electric resistance spot weld (ERSW) processes used for assemblies of components in a body-in-white (BIW) at a world class automotive industry. It is carried out by evaluating the mechanical strength modeled both by experimental and numerical methods. An ""Arcan"" multiaxial test was designed and manufactured in order to enable 0 degrees, 45 degrees and 90 degrees directional loadings. The welded specimens were uncoated low carbon steel sheets (S-y = 170 MPa) used currently at the automotive industry, with two different thicknesses: 0.80 and 1.20 mm. A numerical analysis was carried out using the finite element method (FEM) through LS-DYNA code. (c) 2007 Elsevier B.V. All rights reserved.