FPGA Implementation of a General Space Vector Approach on a 6-Leg Voltage Source Inverter

A general algorithm of a Space Vector approach is implemented on a 6-leg VSI controlling a PM synchronous machine with three independent phases. In this last case, the necessity of controlling the zero-sequence current motivates the choice of a special family of vectors, different of this one used in Pulse Width Modulation (PWM) intersective strategy and in common Space Vector PWM (SVPWM). To preserve the parallelism of the algorithm and fulfill the execution time constraints, the implementation is made on a Field Programmable Gate Array (FPGA). Comparisons with more classical 2-level and 3-level PWM are provided.Fui8 within the SOFRACI projec

Efficient Digital System Management using IEEE 1451.0 Enabled Control Architecture

The IEEE and National Institute of Standards and Technology have formulated an open universal standard called IEEE 1451 for ‘Smart Transducer Interface’ with digital systems. The objectives of this paper is to propose IEEE 21450 enabled control architectures for efficient management of power system with embedded system parameters as electronic documentation. The control architecture accommodates appropriate number of transducer interface module along with transducer electronic data sheet, which enables active calibration, adaptive tuning and failure proof operation of system management

A novel converter topology for applications in smart grids: technical and economical evaluation

Technological advances in smart grids significantly contribute to an energy sustainability paradigm, assisting to diminish harms associated with global warming. Some of the key challenges in smart grids are linked with power electronics applications for renewable energy sources (RES), electric mobility (EM), energy storage systems (ESS) and power quality (PQ). These applications for smart grids have a common feature: the requirement to use the full-controlled grid-side power converters. Thereby, this paper aims to contribute with a technical and economical evaluation about a novel topology of the grid-side power converter for applications in smart grids. In terms of technical features, the proposed converter is classified as: (a) Bidirectional, allowing a bidirectional power flow with the electrical grid; (b) Symmetrical, allowing the operation with two distinct applications in the dc-side (e.g., RES, ESS, or EM); (c) Multilevel with nine levels, allowing high levels of PQ for the grid-side. With the objective to establish an accurate case-study, throughout the paper, the technical and economical evaluation is also performed based on the comparison between the proposed topology and the conventional ones. Considering an economical evaluation, the paper presents a cost estimation study concerning the implementation costs of the proposed topology, assuming realistic conditions of operation for applications in smart grids. Based on the entire evaluation for a real operating power range, the obtained results show the operational convenience of the topology in accordance with different applications in smart grids.This work has been supported by FCT – Fundação para a Ciência e Tecnologia within the Project Scope: UID/CEC/00319/2019. This work is financed by the ERDF – European Regional Development Fund through the Operational Programme for Competitiveness and Internationalisation ‐ COMPETE 2020 Programme, and by National Funds through the Portuguese funding agency, FCT‐Fundação para a Ciência e a Tecnologia, within project SAICTPAC/0004/2015‐ POCI‐01‐0145‐FEDER‐016434.Mr. Tiago Sousa is supported by the doctoral scholarship SFRH/BD/134353/2017 granted by the Portuguese FCT agency. This work is part of the FCT project POCI-01-0145-FEDER-030283

A Comprehensive Review of DC-DC Converters for EV Applications

DC-DC converters in Electric vehicles (EVs) have the role of interfacing power sources to the DC-link and the DC-link to the required voltage levels for usage of different systems in EVs like DC drive, electric traction, entertainment, safety and etc. Improvement of gain and performance in these converters has a huge impact on the overall performance and future of EVs. So, different configurations have been suggested by many researches. In this paper, bidirectional DC-DC converters (BDCs) are divided into four categories as isolated-soft, isolated-hard, non-isolated-soft and non-isolated-hard depending on the isolation and type of switching. Moreover, the control strategies, comparative factors, selection for a specific application and recent trends are reviewed completely. As a matter of fact, over than 200 papers have been categorized and considered to help the researchers who work on BDCs for EV application

Batteries charging systems for electric and plug-in hybrid electric vehicles

Many countries have a large dependence on imported fossil fuels whose prices increase almost every day. Knowing that much of this consumption is for transportation systems, it becomes essential to seek for alternatives. The natural bet is the electric mobility, namely through Electric Vehicles (EVs) and Plug-in Hybrid Electric Vehicles (PHEVs). However, the wide spread utilization of these vehicles has consequences on the electrical power grid, mainly in terms of load management and electric power quality, which are associated to the batteries charging systems. In this scenario, this chapter assesses the electric mobility integration in Smart Grid context, focusing different approaches to the operation of EVs and PHEVs charging processes and the specifications of the chargers, as well as different topologies of charging systems and their features, modes of operation, typical waveforms, and impact in the electrical power grid in terms of power quality. It is also presented a laboratory prototype of a bidirectional EV charger and shown some experimental results. This prototype was developed to charge the batteries aiming to preserve their lifespan, and to contribute to mitigate the degradation of the power quality. The experimental results show the operation of this prototype during the batteries charging process (G2V – Grid-to-Vehicle operation), and during the delivering of stored energy back to the electrical power grid (V2G – Vehicle-to-Grid operation).FEDER Funds - Operational Program for Competitiveness Factors – COMPETEFundação para a Ciência e a Tecnologia (FCT) - FCOMP-01-0124-FEDER-022674, MITPT/ EDAM-SMS/0030/200

An Effective Method of Regenerative Braking for Electric Vehicles

Batteries are commonly used as the power source of plug-in electric vehicles. Low efficiency in a battery is responsible for the low-mileage of electric vehicles. Improving battery efficiency can be done by harvesting the energy wasted during braking, which is commonly called as regenerative braking. The braking energy is to be used to recharge the battery. However, this braking method is not implementable in some conditions, including the conditions when the battery is full, when the vehicle speed is very slow, and when the desired braking currents exceed the converter capability. Therefore, mechanical braking is also still required. This paper proposes a simple but effective technique to deal with the problems found so far in the regenerative braking implementation. The fuzzy-logic theory is implemented to control the sharing proportion between the use of regenerative and electric brakings using one single brake-lever. To improve the current response of electric braking, the proportional-integral control method is used. Being compared to the widely used braking techniques, the method proposed and explored through simulation in this paper offers double advantages, which is increasing the battery efficiency as well as the driving comfort and practicality. The implementation of the method can extend the battery life because the energy regeneration is adapted to the state-of-charge and charging capability of the battery so that the battery can be maintained not to be overcharged

Analysis, modeling, and control of half-bridge current-source converter for energy management of supercapacitor modules in traction applications

In this work, an in-depth investigation was performed on the properties of the half-bridge current-source (HBCS) bidirectional direct current (DC)-to-DC converter, used to interface two DC-link voltage sources with a high-voltage-rating mismatch. The intended implementation is particularly suitable for the interfacing of a supercapacitor (SC) module and a battery stack in a hybrid storage system(HSS) for automotive applications. It is demonstrated that the use of a synchronous rectification (SR) modulation scheme benefits both the power-stage performance (in terms of efficiency and reliability) and the control-stage performance (in terms of simplicity and versatility). Furthermore, an average model of the converter, valid for every operating condition, is derived and utilized as a tool for the design of the control system. This model includes the effects of parasitic elements (mainly the leakage inductance of the transformer) and of the converter snubbers. A 3 kW prototype of the converter was used for experimental validation of the converter modeling, design, and performance. Finally, a discussion on the control strategy of the converter operation is included

Optimal Sizing of Battery/Ultracapacitor-Based Energy Storage Systems in Electric Vehicles

In recent years, electrification of powertrain has gradually become the core of research and development efforts in automotive industry. This is mainly due to the fact that electrified powertrains can effectively alleviate concerns of environmental pollution caused by internal combustion engines (ICEs) and reduce the rate of depletion of the earth's natural resources, while offering a higher efficiency and a better fuel economy. One of the key components of every electric vehicle (EV)/hybrid electric vehicle (HEV) is the Energy Storage System (ESS). An ESS provides propulsion power to the electric drivetrain and captures regenerative braking power. Batteries and ultracapacitors are the most well-known ESS devices for automotive applications. In battery/ultracapacitor-based powertrains, the storage units are configured as series-parallel arrangements of individual cells. In this thesis, the battery and ultracapacitor units are assumed to be composed of parallel branches of series-connected cells. Optimal sizing of the storage unit (determining the optimum numbers of the parallel branches and series-connected cells) and the interfacing infrastructure (if any DC-DC converter exists between the storage unit(s) and the traction motor controller) can have a significant impact on the manufacturing cost of the electric vehicle and its fuel economy. This thesis formulates the problem of optimal sizing of battery/ultracapacitor-based energy storage systems in electric vehicles. Through the course of this research, a flexible optimization platform has been developed. When solving the optimization problem, different constraints such as limits on state of charge, current, and power of the battery cells, current and power of the ultracapacitor cells, voltage conversion of the DC-DC converter, DC bus voltage, and operation characteristics of the inverter and the traction motor are taken into account. This optimization tool is used to solve the problem of optimal sizing of the storage systems for two different classes of vehicles: (i) a small-size, long-range car and (ii) a city bus. Aside from optimal sizing of the storage systems as the main objective, the developed platform provides a proper simulation tool for analyzing the performance of existing electric vehicles on the road

Hybrid fuzzy PI controlled multi-input DC/DC converter for electric vehicle application

Power electronic interface with its effective control scheme plays a major role in the utilization of energy sources for electric vehicle application. For this purpose, a hybrid fuzzy PI based control scheme for a multiple input converter (MIC) topology is proposed. The proposed hybrid fuzzy PI controller includes a conventional PI controller at steady state and fuzzy PI at transient state. Also, the proposed control design helps in tracking a predefined speed profile to have complete realization of electric vehicle. Detailed simulation study and performance comparisons with conventional controller are performed. The results show that the developed control scheme is robust providing bidirectional power management, fast tracking capability with less steady state error, better dynamic response by enhancing the flexibility and proper utilization of energy sources. Simulation in MATLAB/SIMULINK environment is carried out to verify the performance of the multi-input converter with the developed control scheme. An experimental set-up is constructed to validate the same