1,721,067 research outputs found
Predictive control of electrical drives
Full text linkIn this work, the application of the Predictive Control Technique to the electrical drives has been considered and discussed, especially in comparison with the employment of the traditional control techniques. First of all, a predictive control algorithm for the Brushless DC drive is developed with the aim of improving the traditional current commutation as best as possible. Then, a novel predictive control algorithm is proposed by imposing both the reference torque value and the minimum Joule losses condition. Then, several predictive control algorithms are proposed for the Synchronous Reluctance Machine, taking into account the magnetic saturation effects too. They are based either on the traditional control strategy or on optimization criteria, such as the minimum steady state Joule losses condition and the fastest achievement of the reference torque value. Finally, a novel predictive Direct Torque Control algorithm is synthesized for the Asynchronous Machine, by taking into account both voltage saturation and current limitation constraints. The synthesizing procedure adopted is also shown by an interesting graphical representation. The effectiveness of all the proposed algorithms has been properly tested by appropriate simulation studies, performed in the Matlab Simulink environment. The corresponding results have highlighted how the employment of the Predictive Control Technique allows better performances compared to those achievable by the traditional control ones
A Flux-Weakening Predictive Control Algorithm for Extended Constant-Power Operation of Surface-Mounted PM Machines
No full textA flux-weakening predictive control algorithm (FWPC) is proposed in this paper with the aim of extending Constant-Power Speed Range (CPSR) of Surface-Mounted Permanent Magnet Synchronous Machines (SPMs). The proposed FWPC is developed on the basis of an accurate SPM sampled-data model and consists of appropriately exploiting the DC-link voltage reserve that is generally set aside for dynamic purpose only. This goal is achieved by optimal and easy management of SPM operating constraints, i.e. current limitation and voltage saturation, without impairing SPM dynamic performances. The effectiveness of the proposed FWPC is verified through both simulation and experimental studies, which highlight the enhancement of SPM performances, especially in terms of CPSR extension
Modeling, Control and Prototyping of a Highly Integrated Battery-Ultracapacitor System for Microgrids
No full textA Highly-Integrated Battery-UltraCapacitor system (HIBUC) is presented in this paper. It consists of a battery pack and an ultracapacitor module, which are coupled to each other through a three-level neutral-point-clamped converter. The latter is connected to the point of common coupling between a microgrid and the main electric grid through a step-up transformer, which enables lower DC-link voltage rating and, thus, eases HIBUC prototyping without affecting its performances significantly. The DC-link is also connected to a dissipative voltage regulator, which has been designed with the dual purpose of preventing DC-link overvoltage and improving DC-link voltage regulation simultaneously. The effectiveness of the proposed configuration has been verified through a simulation study, which has been carried out in the Matlab-Simulink environment and refers to different HIBUC operating conditions
Electrification of Commercial Vessels: Pilot Projects and Open Issues
No full textThis paper presents a brief overview of some of the most recent pilot projects on vessel electrification, with particular reference to ferries and off-shore vessels. Firstly, the paper resumes the main technological improvements, which enable marine electrification and mainly regard power electronics and electric propulsion systems. Subsequently, the focus is on the description of some pilot projects, grouping them into two main categories, namely ferries and off-shore vessels, which are characterized by different usage and, thus, electrification needs. In conclusion, main features, challenges, and outcomes of each project are highlighted, as well as the overall pending issues, final remarks and future developments
Hybrid Energy Storage Systems for Smart Grids and Electric Propulsion Systems
No full textHybrid Energy Storage Systems (HESSs) represent a very promising and viable solution for the widespread diffusion of both Smart Grids (SGs) and Electric Propulsion Systems (EPSs). This is because an HESS benefits from two or more energy storage technologies that are characterized by complementary features, namely high energy and high power densities. Consequently, a number of energy and power services can be provided successfully, which are hardly deliverable by a single energy storage technology unless oversizing is concerned. Therefore, HESSs installed in SGs can provide multiple grid services, ranging from peak shaving to power quality, thus achieving an economic viability. While the employment of an HESS for supplying EPSs enables improved dynamic performances and energy efficiency during both acceleration and regenerative braking, thus extending the vehicle driving range. In this context, an HESS made up of batteries and supercapacitors is the most popular combination, it being suitable for both small-scale and large-scale applications due to its inherent modularity. However, HESS technical and economic viability strictly relies on management and control, which should enable the exploitation of the HESS inherent features to the maximum extent in accordance with the application requirements.
In this regard, the presentation will focus on most recent advancements in management and control of HESS for both SG and EPS. Particularly, the most popular HESS configurations, management and control approaches will be introduced at first, highlighting their most important advantages and drawbacks. Subsequently, a highly-integrated HESS configuration will be presented, which is well suited for SGs, but especially for EPSs. This is because it benefits from the advantages of both passive and active HESS configurations due to its inherent flexibility. An Optimal HESS Power and Energy Management (OPEM) for SGs will be presented as well; this has been developed analytically in order to achieve an optimal trade-off between peak shaving and reduced grid energy buffering, providing power quality and preventing an excessive battery cycling at the same time. Preliminary and advanced results will be presented and discussed extensively, which highlight the effectiveness of the proposed solutions in terms of HESS configuration, management and control
Design and Implementation of Model Predictive Control Algorithms for Permanent Magnet Synchronous Machines on FPGA-based Control Boards
No full textElectromagnetic Losses Minimization in High-Speed Flywheel Energy Storage Systems
Full text linkThis paper deals with electromagnetic loss analysis and minimization in an integrated Flywheel Energy Storage System (FESS). The FESS consists of a large-airgap Surface-Mounted Permanent Magnet Synchronous Machine (SPM), whose inner rotor integrates a carbon-fiber flywheel, leading to a compact and efficient FESS. Electromagnetic losses minimization is achieved through an accurate SPM modelling, which accounts for both Joule and core losses, as well as for flux-weakening operation. Consequently, SPM maximum efficiency is obtained by injecting a proper demagnetization current component at each operating condition, which guarantee the optimal trade-off among the different losses’ contributions. The effectiveness of the proposed approach is validated through numerical simulations
A Brief Overview on Commercial Aircraft Electrification: Limits and Future Trends
No full textThis paper presents a brief overview of aircraft electrification, particularly regarding the commercial aviation sector. At first, a technology overview is presented by focusing on aircraft design, propulsion, and energy storage systems. In this regard, hybrid-electric propulsion systems seem the most suitable solution at present due to technological limitations, especially the still low energy performance of electrochemical batteries. Subsequently, some prototypes are presented, which have been classified in long-range, medium-short range, and urban transportation; many of them are just at the concept stage as they rely on technologies not yet available. The most important issues to address are then resumed, together with future developments and concluding remarks
A Real-Time Energy Management System for Operating Cost Minimization of Fuel Cell/Battery Electric Vehicles
No full textThis paper presents a Real-Time Energy Management System (RT-EMS) for minimizing the operating costs of a Fuel Cell/Battery Electric Vehicle (FCBEV). Particularly, a suitable cost function is considered, which accounts for battery and fuel cell degradation, as well as for fuel consumption and battery charging reinstatement. The cost function is thus minimized in real-time by a suitable energy management strategy, which is designed based on an appropriate model of the overall electric propulsion system. In this regard, a suitable power split criterion is determined, based on which the proposed RT-EMS shares the propulsion power between fuel cell and battery. As a result, the cost function can be minimized whatever the driving cycle is. The effectiveness of the proposed RT-EMS has been assessed by numerical simulations, which have been performed in Matlab-Simulink considering different driving cycles and a hysteresis-based EMS for comparison purposes
Discrete-Time Parameter Identification of a Surface-Mounted Permanent Magnet Synchronous Machine
No full textA novel online discrete-time parameters identification algorithm suitable for surface-mounted permanent magnet synchronous machines (SPMs) is presented in this paper. It is developed by means of the Model Reference Adaptive System (MRAS) technique and the Popov Hyperstability Criterion in order to identify SPM discrete-time model parameters. In particular, good accuracy of discrete-time parameters is required by digital control systems, especially by predictive control algorithms, which present a low robustness against parameters mismatches. Hence, an extensive simulation study is firstly carried out in the Matlab Simulink environment with the aim of testing the effectiveness and robustness of the proposed identification algorithm against inverter un-idealities. Then, the proposed identification procedure is experimentally validated on a predictive controlled radial-flux SPM, driven by a Field Programmable Gate Arrays (FPGA) control board
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