Performances comparison of different concentrated-winding configurations for 5-phase PMSG in normal and faulty modes in flux weakening operation for fixed pitch tidal turbines

This paper aims to evaluate some configurations of windings for low speed high power 5-phase permanent magnet synchronous generators (PMSG) associated to fixed pitch tidal turbines. Several Fractional-Slot Concentrated- Windings has been considered and compared for these specifications. The proposed structures are compared in terms of torque VS speed characteristics, including flux weakening operation, in healthy and faulty modes. In fault mode, the failure of one and two phases is considered. The results show that concentrated windings can be particularly useful for these particular specifications

Experimental Investigation of Decoupled Discontinuous PWM Strategies in Open-End Winding Induction Motor Supplied by a Common DC-link

© 2023 IEEE. This is the accepted manuscript version of an article which has been published in final form at https://doi.org/10.1109/JESTPE.2023.3258799Currently, open-end winding induction motors fed by a dual inverter (OEWIM-DI) present an innovative approach to enhance the performance of modern electric drive systems, such as electrical vehicles and electric aircraft applications. However, the DI topology requires a proper switching control strategy to enable the OEWIM drive to fully achieve its performance. This work aims to investigate experimentally the impact of different decoupled discontinuous pulsewidth modulation (DDPWM) control strategies on the performance of the OEWIM-DI supplied by a common dc-link. The criteria performances adopted in this study are: 1) the total harmonic distortion (THD) of the current and voltage; 2) the zero sequence voltage (ZSV); 3) the common mode voltage (CMV); and 4) the DI losses. The various DDPWM control schemes for the 1.5-kW OEWIM-DI motor drive are implemented on a dSPACE 1104 board, and the results are compared with the popular and widely used space-vector PWM (SVPWM) strategy. From the results, it can be concluded that the optimized DDPWM technique gives the best performance. This technique has reduced the CMV by one level and reduces the losses by 50% while having the same THD and ZSV obtained with the SVPWM technique.Peer reviewe

Reliability-Oriented Design of Vehicle Electric Propulsion System Based on the Multilevel Hierarchical Reliability Model

This chapter describes a methodology of evaluation of the various sustainability indicators, such as reliability, availability, fault tolerance, and reliability-associated cost of the electric propulsion systems, based on a multilevel hierarchical reliability model (MLHRM) of the life cycles of electric vehicles. Considering that the vehicle propulsion systems are safety-critical systems, to each of their components, the strict requirements on reliability indices are imposed. The practical application of the proposed technique for reliability-oriented development of the icebreaking ship’s electric propulsion system and the results of computation are presented. The opportunities of improvement of reliability and fault tolerance are investigated. The results of the study, allowing creating highly reliable electric vehicles and choosing the most appropriate traction electric drive design, are discussed

Protection of physically compact multiterminal DC power systems

The use of DC for primary power distribution has the potential to bring significant design, cost and efficiency benefits to microgrid, shipboard and aircraft applications. The integration of active converter technologies within these networks is a key enabler for these benefits to be realised, however their influence on an electrical network's fault response can lead to exceptionally demanding protection requirements. This represents a significant barrier to more widespread adoption of DC power distribution. The principle challenge within the field is to develop protection solutions which do not significantly detract from the advantages which DC networks offer. This objective leads the thesis to not only consider how the protection challenges may be overcome but also how this can be achieved in a manner which can benefit the overall design of a system, inclusive of various system design objectives. The thesis proposes that this objective can be achieved through the operation of network protection within the initial transient period following the occurrence of a fault. In seeking to achieve this aim, the work presented within this thesis makes a number of contributions. The thesis categorises converter type based on the components which influence their fault response and then presents an analysis of the natural fault response of compact multiterminal DC power distribution networks containing these converters. Key factors such as the peak magnitudes and formation times of fault current profiles are determined and quantified as a function of network parameters, enabling protection system operating requirements to be established. Secondary fault effects such as voltage transients are also identified and quantified to illustrate the impact of suboptimal protection system operation. The capabilities of different protection methods and technologies for achieving the proposed operating requirements are then analysed. Significant conclusions are: solid state breaking technologies are essential to achieving operating targets and severe limitations exist with the application of protection methods available within literature for this application. To overcome these shortfalls, novel fault detection approaches are proposed and analysed. These approaches enable fault detection time targets to be met as well as aid with the effective integration of future circuit breaking technologies

Control solutions for multiphase permanent magnet synchronous machine drives applied to electric vehicles

207 p.En esta tesis se estudia la utilización de un accionamiento eléctrico basado en una máquina simétrica dual trifásica aplicada al sistema de propulsión de un vehículo eléctrico. Dicho accionamiento está basado en una máquina síncrona de imanes permanentes interiores. Además, dispone de un bus CC con una configuración en cascada. Por otra parte, se incorpora un convertidor CC/CC entre el módulo de baterías y el inversor de seis fases para proveer el vehículo con capacidades de carga rápida, y evitando al mismo tiempo la utilización de semiconductores de potencia con altas tensiones nominales. En este escenario, el algoritmo de control debe hacer frente a las no linealidades de la máquina, proporcionando un comando de consigna preciso para todo el rango de par y velocidad del convertidor. Por lo tanto, deben tenerse en cuenta los efectos de acoplamiento cruzado entre los devanados, y la tensión de los condensadores de enlace en cascada debe controlarse y equilibrarse activamente. En vista de ello, los autores proponen un novedoso enfoque de control que proporciona todas estas funcionalidades. La propuesta se ha validado experimentalmente en un prototipo a escala real de accionamiento eléctrico de 70 kW, probado en un laboratorio y en un vehículo eléctrico en condiciones reales de conducción.Tecnali

On the potential of parallel powertrains to reduce the cost of energy from offshore wind turbines

Offshore wind turbine operating conditions are challenging with access for maintenance being limited by weather to a greater degree than for onshore turbines, resulting in prolonged downtime and reduced availability. This makes operational costs (helicopter, crew transfer or heavy lift vessels) more expensive, leads to loss of energy production and tends to increase the cost of energy of offshore wind farms. It is therefore important to investigate potential strategies that could improve availability, energy production and at the same time reduce operation and maintenance (O&M) cost and cost of energy in the long run. One possible option for availability improvement and cost of energy reduction is through the powertrain design. Most of the existing wind turbine types could be distinguished through their powertrain configurations. Conventional wind turbine powertrain exhibits single-input-single-output topology (one gearbox coupled to a generator with a power converter) while some exist with no gearbox (gearless drive). Although some of the geared and gearless powertrains have some good availability, yet they are still susceptible to prolonged downtime and consequently significant energy loss. This has alarmed the need to introduce the concept of parallelism into the design of offshore wind turbine powertrain. This research, therefore, focusses on a configuration with single-input-multiple-output (parallel powertrain) subsystems as a strategy for improvements in availability, energy production and cost of energy reduction. The novelty of this work comes from the availability improvement of small parallel subsystem with reduced failure rate, extra energy production at failure states, reduction in (O&M) cost due to high repair rate and the resulting cost of energy reduction of parallel powertrain. The highest-level research question amongst all of the research questions answered in this work is: "Can parallel powertrains reduce the cost of energy of offshore wind turbines?" In attempting to address this key question and other secondary research questions, in Chapter 3 the author carries out survey and analysis of failure and repair rate data from published sources to determine how they vary with powertrain configuration, power ratings, and sizes. In Chapter 4, a baseline powertrain availability and that of different parallel powertrains are evaluated using Markov state space model (MSSM). In Chapter 5, the annual energy production (AEP) of parallel powertrain is analysed using Raleigh probability distribution and the rated power in order to quantify any extra benefit at below rated wind speed. The ideal AEP is analysed at rated power, rated wind speed and at no-failure state. Also, the losses and efficiency of parallel powertrain at failure states are evaluated. Chapter 6 estimates the O&M costs of parallel powertrains using offshore accessibility tool. Chapter 7 calculates the cost of energy of parallel powertrain using AEP and O&M cost results from previous chapters in combination to initial capital cost (ICC). Finally, a general conclusion is made in Chapter 8. The novel results from each chapter provide some new insight into the potential of the parallel powertrain. The thesis concludes that an increase in the number of parallel systems, N, does not automatically lead to a higher availability for a wind turbine powertrain; however, when failure and repair rates scale with module power ratings then there is an improvement. It is possible to have extra AEP at below rated wind speed and at the various failure states of parallel powertrain. Potential reduction in the cost of energy is also observed with the parallel powertrain at below rated wind speed and failure states.The results shown in this thesis will be useful for offshore wind farm developers, operators and wind turbine manufacturers. It can be useful to developers when deciding and selecting the type of powertrain. Operators can gain insight into the driving factors of O&M costs. Manufacturers can consider which type of wind turbine powertrain to develop and manufacture to satisfy one of their key customer requirements, a lower cost of energy.Offshore wind turbine operating conditions are challenging with access for maintenance being limited by weather to a greater degree than for onshore turbines, resulting in prolonged downtime and reduced availability. This makes operational costs (helicopter, crew transfer or heavy lift vessels) more expensive, leads to loss of energy production and tends to increase the cost of energy of offshore wind farms. It is therefore important to investigate potential strategies that could improve availability, energy production and at the same time reduce operation and maintenance (O&M) cost and cost of energy in the long run. One possible option for availability improvement and cost of energy reduction is through the powertrain design. Most of the existing wind turbine types could be distinguished through their powertrain configurations. Conventional wind turbine powertrain exhibits single-input-single-output topology (one gearbox coupled to a generator with a power converter) while some exist with no gearbox (gearless drive). Although some of the geared and gearless powertrains have some good availability, yet they are still susceptible to prolonged downtime and consequently significant energy loss. This has alarmed the need to introduce the concept of parallelism into the design of offshore wind turbine powertrain. This research, therefore, focusses on a configuration with single-input-multiple-output (parallel powertrain) subsystems as a strategy for improvements in availability, energy production and cost of energy reduction. The novelty of this work comes from the availability improvement of small parallel subsystem with reduced failure rate, extra energy production at failure states, reduction in (O&M) cost due to high repair rate and the resulting cost of energy reduction of parallel powertrain. The highest-level research question amongst all of the research questions answered in this work is: "Can parallel powertrains reduce the cost of energy of offshore wind turbines?" In attempting to address this key question and other secondary research questions, in Chapter 3 the author carries out survey and analysis of failure and repair rate data from published sources to determine how they vary with powertrain configuration, power ratings, and sizes. In Chapter 4, a baseline powertrain availability and that of different parallel powertrains are evaluated using Markov state space model (MSSM). In Chapter 5, the annual energy production (AEP) of parallel powertrain is analysed using Raleigh probability distribution and the rated power in order to quantify any extra benefit at below rated wind speed. The ideal AEP is analysed at rated power, rated wind speed and at no-failure state. Also, the losses and efficiency of parallel powertrain at failure states are evaluated. Chapter 6 estimates the O&M costs of parallel powertrains using offshore accessibility tool. Chapter 7 calculates the cost of energy of parallel powertrain using AEP and O&M cost results from previous chapters in combination to initial capital cost (ICC). Finally, a general conclusion is made in Chapter 8. The novel results from each chapter provide some new insight into the potential of the parallel powertrain. The thesis concludes that an increase in the number of parallel systems, N, does not automatically lead to a higher availability for a wind turbine powertrain; however, when failure and repair rates scale with module power ratings then there is an improvement. It is possible to have extra AEP at below rated wind speed and at the various failure states of parallel powertrain. Potential reduction in the cost of energy is also observed with the parallel powertrain at below rated wind speed and failure states.The results shown in this thesis will be useful for offshore wind farm developers, operators and wind turbine manufacturers. It can be useful to developers when deciding and selecting the type of powertrain. Operators can gain insight into the driving factors of O&M costs. Manufacturers can consider which type of wind turbine powertrain to develop and manufacture to satisfy one of their key customer requirements, a lower cost of energy

Advances in Condition Monitoring, Optimization and Control for Complex Industrial Processes

The book documents 25 papers collected from the Special Issue “Advances in Condition Monitoring, Optimization and Control for Complex Industrial Processes”, highlighting recent research trends in complex industrial processes. The book aims to stimulate the research field and be of benefit to readers from both academic institutes and industrial sectors