Design and implementation of synchronous buck converter based PV energy system for battery charging applications

The Photo Voltaic (PV) energy system is a very new concept in use, which is gaining popularity due to increasing importance to research on alternative sources of energy over depletion of the conventional fossil fuels world-wide. The systems are being developed to extract energy from the sun in the most efficient manner and suit them to the available loads without affecting their performance. In this project, synchronous buck converter based PV energy system for portable applications; especially low power device applications such as charging mobile phone batteries are considered. Here, the converter topology used uses soft switching technique to reduce the switching losses which is found prominently in the conventional buck converter, thus efficiency of the system is improved and the heating of MOSFETs due to switching losses reduce and the MOSFETs have a longer life. The DC power extracted from the PV array is synthesized and modulated by the converter to suit the load requirements. Further, the comparative study between the proposed synchronous buck converter and the conventional buck converter is analysed in terms of efficiency improvement and switching loss reduction. The proposed system is simulated in the MATLAB-Simulink environment and the practical implementation of the proposed converter is done to validate the theoretical results. Open-loop control of synchronous buck converter based PV energy system is realised through ICs and experimental results were observed

Survey on Photo-Voltaic Powered Interleaved Converter System

Renewable energy is the best solution to meet the growing demand for energy in the country. The solar energy is considered as the most promising energy by the researchers due to its abundant availability, eco-friendly nature, long lasting nature, wide range of application and above all it is a maintenance free system. The energy absorbed by the earth can satisfy 15000 times of today’s total energy demand and its hundred times more than that our conventional energy like coal and other fossil fuels. Though, there are overwhelming advantages in solar energy, It has few drawbacks as well such as its low conversion ratio, inconsistent supply of energy due to variation in the sun light, less efficiency due to ripples in the converter, time dependent and, above all, high capitation cost. These aforementioned flaws have been addressed by the researchers in order to extract maximum energy and attain hundred percentage benefits of this heavenly resource. So, this chapter presents a comprehensive investigation based on photo voltaic (PV) system requirements with the following constraints such as system efficiency, system gain, dynamic response, switching losses are investigated. The overview exhibits and identifies the requirements of a best PV power generation system

A quadratic boost converter derived multi output converter for electric vehicles application

A novel Solar Photo Voltaic Powered dual output DC to DC converter with the Quadratic Boost Converter as the core element, typically for Electrical Vehicle applications has been proposed and validated in this work. The proposed system harvests the solar power and charges a 12 V battery, supplies power to a 12 V load, using the buck feature of the proposed converter. A second channel of 48 V output is derived using the boost channel and the 48 V output is meant for driving the traction motor as well as any other load that requires a regulated 48 V. The proposed converter can operate in three different modes. For the purpose of voltage regulation at the 48 V and 12 V output channels and for the Maximum Power Point Tracking, applicable to the Solar Photo Voltaic source, individual Sliding Mode Controllers are used. The proposed idea has been validated using simulations in the MATLAB SIMULINK environment and an experimental prototype

Multiple Output Battery Charging Circuit for Bikers

Bikers want to charge their devices containing batteries (such as smart phones, bicycle headlight, head cameras), which they need in their daily lives, with the energy produced by their bicycles. A device capable of storing kinetic energy of bikers contributes to environment friendly electric power generation. This paper presents a multiple output battery charging circuit design for bikers. Proposed design consists of a dynamo capable of producing 12 V and it charges 2 × 4000 mAh storage batteries with a buck converter that produces an output voltage of 1.29 A 4.2 V. Li-ion batteries are the most suitable batteries for portable storage applications due to their compact size, light weight and long-life time features. 2 × 4000 mAh Li-ion batteries charge a 5 V 2000 mAh battery with a boost converter. Proposed method is simulated using MATLAB/Simulink. The simulation results are compared with the experimental results. The simulation and experimental results are in accordance with each other. A biker using the device suggested in the study will be able to ride an average of 2 hours a day and store the energy to fully charge the smart phone or bike headlight or head camera with 1 week of use

Advanced Statistical Modeling, Forecasting, and Fault Detection in Renewable Energy Systems

Fault detection, control, and forecasting have a vital role in renewable energy systems (Photovoltaics (PV) and wind turbines (WTs)) to improve their productivity, ef?ciency, and safety, and to avoid expensive maintenance. For instance, the main crucial and challenging issue in solar and wind energy production is the volatility of intermittent power generation due mainly to weather conditions. This fact usually limits the integration of PV systems and WTs into the power grid. Hence, accurately forecasting power generation in PV and WTs is of great importance for daily/hourly efficient management of power grid production, delivery, and storage, as well as for decision-making on the energy market. Also, accurate and prompt fault detection and diagnosis strategies are required to improve efficiencies of renewable energy systems, avoid the high cost of maintenance, and reduce risks of fire hazards, which could affect both personnel and installed equipment. This book intends to provide the reader with advanced statistical modeling, forecasting, and fault detection techniques in renewable energy systems

Small Scale Maximum Power Point Tracking Power Converter for Developing Country Application

This thesis begins with providing a basic introduction of electricity requirements for small developing country communities serviced by small scale generating units (focussing mainly on small wind turbine, small Photo Voltaic system and Micro-Hydro Power Plants). Scenarios of these small scale units around the world are presented. Companies manufacturing different size wind turbines are surveyed in order to propose a design that suits the most abundantly available and affordable turbines. Different Maximum Power Point Tracking (MPPT) algorithms normally employed for these small scale generating units are listed along with their working principles. Most of these algorithms for MPPT do not require any mechanical sensors in order to sense the control parameters like wind speed and rotor speed (for small wind turbines), temperature and irradiation (for PV systems), and water flow and water head (for Micro-Hydro). Models for all three of these systems were developed in order to generate Maximum Power Point (MPP) curves. Similarly, a model for Permanent Magnet Synchronous Generators (PMSGs) has been developed in the d-q reference frame. A boost rectifier which enables active Power Factor Correction (PFC) and has a DC regulated output voltage is proposed before implementing a MPPT algorithm. The proposed boost rectifier works on the principle of Direct Power Control Space Vector Modulation (DPC-SVM) which is based on instantaneous active and reactive power control loops. In this technique, the switching states are determined according to the errors between commanded and estimated values of active and reactive powers. The PMSG and Wind Turbine behaviour are simulated at various wind speeds. Similarly, simulation of the proposed PFC boost rectifier is performed in matlab/simulink. The output of these models are observed for the variable wind speeds which identifies PFC and boosted constant DC output voltage is obtained. A buck converter that employs the MPPT algorithm is proposed and modeled. The model of a complete system that consists of a variable speed small wind turbine, PMSG, DPC-SVM boost rectifier, and buck converter implementing MPPT algorithm is developed. The proposed MPPT algorithm is based upon the principle of adjusting the duty ratio of the buck converter in order reach the MPP for different wind speeds (for small wind turbines) and different water flow rates (Micro-Hydro). Finally, a prototype DPC-SVM boost rectifier and buck converter was designed and built for a turbine with an output power ranging from 50 W-1 kW. Inductors for the boost rectifier and buck DC-DC converter were designed and built for these output power ranges. A microcontroller was programmed in order to generate three switching signals for the PFC boost rectifier and one switching signal for the MPPT buck converter. Three phase voltages and currents were sensed to determine active and reactive power. The voltage vectors were divided into 12 sectors and a switching algorithm based on the DPC-SVM boost rectifier model was implemented in order to minimize the errors between commanded and estimated values of active and reactive power. The system was designed for charging 48 V battery bank. The generator three phase voltage is boosted to a constant 80 V DC. Simulation results of the DPC-SVM based rectifier shows that the output power could be varied by varying the DC load maintaining UPF and constant boosted DC voltage. A buck DC-DC converter is proposed after the boost rectifier stage in order to charge the 48 V battery bank. Duty ratio of the buck converter is varied for varying the output power in order to reach the MPP. The controller prototype was designed and developed. A laboratory setup connecting 4 kW induction motor (behaving as a wind turbine) with 1kW PMSG was built. Speed-torque characteristic of the induction motor is initially determined. The torque out of the motor varies with the motor speed at various motor supply voltages. At a particular supply voltage, the motor torque reaches peak power at a certain turbine speed. Hence, the control algorithm is tested to reach this power point. Although the prototype of the entire system was built, complete results were not obtained due to various time constraints. Results from the boost rectifier showed that the appropriate switching were performed according to the digitized signals of the active and reactive power errors for different voltage sectors. Simulation results showed that for various wind speed, a constant DC voltage of 80 V DC is achieved along with UPF. MPPT control algorithm was tested for induction motor and PMSG combination. Results showed that the MPPT could be achieved by varying the buck converter duty ratio with UPF achieved at various wind speeds

Compact Micro scale Multi- Source (Solar and Thermal) Energy harvesting IC with regulated Multi load Power Management scheme

Power is required for all man-made systems to work and perform their corresponding activi-ties.Generation of power in large scale is carried out from power grids and supplied to systems that need high power whereas systems requiring less power are supplied from batteries. Batteries need to be replaced after their lifetime which seem to be a less attractive option in applications where systems are placed out of reach for humans as WSN nodes or in some of biomedical systems which are kept inside human body. The need for a self-supporting system i.e. a system that produces energy by itself and supports all the modules by powering them by itself is increased. A harvesting system that harvests energy from the ambience and converting that energy into electrical form and supplying the power to loads or storing in a battery is the solution for all the problems mentioned above. Solar, thermal, vibration and RF are the sources in the ambience from which energy can be harvested and supplied to load or charged into a battery. Availability of a single energy source(thermal,vibration,solar,RF) at all instances cannot be guaranteed creating a situation of insufficient supply of power to loads or unable to charge the load capacitor to the required voltage. Usage of multiple sources for harvesting energy is a prominent solution to the above mentioned problem. Designing a microscale energy harvesting from multiple sources is the main motto behind the current work.TEG and piezo are compatible to be used alternatively in the system because of their close resemblance in their energy densities. Therefore TEG and piezo have been used as two input sources for the system. The other modules in the system include design of a buck boost power converter that switches between buck and boost modes depending on the source connected to the system and the input voltage available at the input. The other module being a digital controller that generates clocks for power switches, signals that decide if TEG or PV need to be connected to the system.Intra source selection block for TEG array where multiple TEG sources switch between series or parallel depending on the voltage available across each TEG source so as to increase the net power from the TEG. The load is a capacitor that needs to be charged to 1.8V where the system stops working once the capacitor gets charged to the desired voltage. Idea of sharing a single inductor between two different sources without using two power converters for individual sources is implemented. Using the dead time of inductor current of TEG for PV source is the main thought behind the development of the current system. System is designed considering all the specifications, constraints, functionalit

Electric Vehicles Charging Stations’ Architectures, Criteria, Power Converters, and Control Strategies in Microgrids

Electric Vehicles (EV) usage is increasing over the last few years due to a rise in fossil fuel prices and the rate of increasing carbon dioxide (CO2) emissions. The EV charging stations are powered by the existing utility power grid systems, increasing the stress on the utility grid and the load demand at the distribution side. The DC grid-based EV charging is more efficient than the AC distribution because of its higher reliability, power conversion efficiency, simple interfacing with renewable energy sources (RESs), and integration of energy storage units (ESU). The RES-generated power storage in local ESU is an alternative solution for managing the utility grid demand. In addition, to maintain the EV charging demand at the microgrid levels, energy management and control strategies must carefully power the EV battery charging unit. Also, charging stations require dedicated converter topologies, control strategies and need to follow the levels and standards. Based on the EV, ESU, and RES accessibility, the different types of microgrids architecture and control strategies are used to ensure the optimum operation at the EV charging point. Based on the above said merits, this review paper presents the different RES-connected architecture and control strategies used in EV charging stations. This study highlights the importance of different charging station architectures with the current power converter topologies proposed in the literature. In addition, the comparison of the microgrid-based charging station architecture with its energy management, control strategies, and charging converter controls are also presented. The different levels and types of the charging station used for EV charging, in addition to controls and connectors used in the charging station, are discussed. The experiment-based energy management strategy is developed for controlling the power flow among the available sources and charging terminals for the effective utilization of generated renewable power. The main motive of the EMS and its control is to maximize usage of RES consumption. This review also provides the challenges and opportunities for EV charging, considering selecting charging stations in the conclusion.publishedVersio

ELECTRIFICATION OF THE VEHICLE PROPULSION SYSTEM – AN OVERVIEW

To achieve EU targets for 2020, internal combustion engine cars need to be gradually replaced with hybrid or electric ones, which have low or zero GHG emission. The paper presents a short overview of dynamic history of the electric vehicles, which led to nowadays modern solutions. Different possibilities for the electric power system realizations are described. Electric vehicle (EV) operation is analyzed in more details. Market future of EVs is discussed and plans for 2020, up to 2030 are presented. Other effects of electrification of the vehicles are also analyzed

Innovation in Energy Systems

It has been a little over a century since the inception of interconnected networks and little has changed in the way that they are operated. Demand-supply balance methods, protection schemes, business models for electric power companies, and future development considerations have remained the same until very recently. Distributed generators, storage devices, and electric vehicles have become widespread and disrupted century-old bulk generation - bulk transmission operation. Distribution networks are no longer passive networks and now contribute to power generation. Old billing and energy trading schemes cannot accommodate this change and need revision. Furthermore, bidirectional power flow is an unprecedented phenomenon in distribution networks and traditional protection schemes require a thorough fix for proper operation. This book aims to cover new technologies, methods, and approaches developed to meet the needs of this changing field