Discussion of the technology and research in fuel injectors common rail system

Common rail is one of the most important components in a diesel and gasoline direct injection system. It features a high-pressure (100 bar) fuel rail feeding solenoid valves, as opposed to a low-pressure fuel pump feeding unit injectors. Third-generation common rail diesels now feature piezoelectric injectors for increased precision, with fuel pressures up to 2,500 bar. The purpose of this review paper is to investigate the technology and research in fuel injectors common rail system. This review paper focuses on component of common rail injection system, pioneer of common rail injection, characteristics of common rail injection system, method to reduce smoke and NOx emission simultaneously and impact of common rail injection system. Based on our research, it can be concluded that common rail injection gives many benefit such as good for the engine performance, safe to use, and for to reduce the emission of the vehicle. Fuel injection common rail system is the modern technology that must be developed. Nowadays, our earth is polluting by vehicle output such as smoke. If the common rail system is developed, it can reduce the pollution and keep our atmosphere clean and safe

One-Quadrant Switched-Mode Power Converters

This article presents the main topics related to one-quadrant power converters. The basic topologies are analysed and a simple methodology to obtain the steady-state output-input voltage ratio is set out. A short discussion of different methods to control one-quadrant power converters is presented. Some of the reported derived topologies of one-quadrant power converters are also considered. Some topics related to one-quadrant power converters such as synchronous rectification, hard and soft commutation, and interleaved converters are discussed. Finally, a brief introduction to resonant converters is given.Comment: 25 pages, contribution to the 2014 CAS - CERN Accelerator School: Power Converters, Baden, Switzerland, 7-14 May 201

On supplying LEDs from very low dc voltages with high frequency AC-LED drivers

This work studies the driving of white Light Emitting Diodes (LEDs) from very low voltages in the range of 1.2 to 2 V. The proposed idea is based on replacing the standard Schottky diode used in conventional converter topologies (i.e., buck, buck-boost and boost) with an LED, while shortcutting the output of the converter. In this configuration, the LED works both as the load and as the rectifier diode of the converter, hence, switching the LED at high frequencies (i.e. > 100 kHz). Moreover, a thorough analytical study is carried out for the two topologies rendered in this work. Particularly emphasizing their static analysis and the obtaining of the boundaries between the different conduction modes. Finally, the idea is validated experimentally by means of the boost converter variation (i.e., DL//S AC-LED driver). The DL//S AC-LED driver has also been compared with a dc-dc boost converter showing a better luminous efficacy while disposing of the Schottky diode and the output capacitor. This analysis is carried out when connected to a Li-Ion battery using a simple control and integrated circuit for its development.This work has been supported by the Spanish Government under Project MINECO-17-DPI2016-75760-R and the Principality of Asturias under the grants “Severo Ochoa” BP14-142 and by the Project SV-PA-17-RIS3-4, and by European Regional Development Fund (ERDF) grants

Regenerative braking using buckboost converter

A Buck Boost converter circuit has been designed and simulated to drive a dc motor for an electric vehicle. The design consists of an IGBT Buck-Boost converter, the battery pack in the Buck side and a capacitor in the Boost side. The main battery has the motor load connected to it. The design helps in improving the efficiency of the DC motor by using the bidirectional buck boost converter along with the battery pack and capacitor.It provides energy to the motor during acceleration and also facilitates the energy regeneration during braking or deceleration. The incorporation of the regenerative braking can improve the efficiency as much as 25% and therefore improve the driving range. During boost operation the converter transfers the energy from the capacitor to the battery(battery gets charged) while during regeneration converter works in buck mode and transfers energy from battery to capacitor(capacitor is charged).There are a number of options for DC DC converter such as Boost,Buck converter, Isolated/Non isolated Half bridge Buck Boost converter,Full Bridge converter and ,Cuk Converter.The isolated converters are preferred as they don’t include transformers and hence increase the overall efficiency of the system along with reduction of size and weight of the system.A controller was designed to generate a controlled PWM signal input to the igbt switches. The battery voltage is measured and an error signal is generated with respect to a reference voltage. This error is given as input to a PI controller and the controller generates a PWM switching pattern by using a comparator. The controller thus controls the amount of energy transferred to the capacitor.In present work the controller is designed and simulated for both the operating modes-Buck mode and Boost mode

High-Voltage-Gain DC-DC Power Electronic Converters -- New Topologies and Classification

This dissertation proposes two new high-voltage-gain dc-dc converters for integration of renewable energy sources in 380/400V dc distribution systems. The first high-voltage-gain converter is based on a modified Dickson charge pump voltage multiplier circuit. The second high-voltage-gain converter is based on a non-inverting diode-capacitor voltage multiplier cell. Both the proposed converters offer continuous input current and low voltage stress on switches which make them appealing for applications like integration of renewable energy sources. The proposed converters are capable for drawing power from a single source or two sources while having continuous input current in both cases. Theoretical analysis of the operation of the proposed converters and the component stresses are discussed with supporting simulation and hardware results. This dissertation also proposes a family of high-voltage-gain dc-dc converters that are based on a generalized structure. The two stage general structure consists of a two-phase interleaved (TPI) boost stage and a voltage multiplier (VM) stage. The TPI boost stage results in a classification of the family of converters into non-isolated and isolated converters. A few possible VM stages are discussed. The voltage gain derivations of the TPI boost stages and VM stages are presented in detail. An example converter is discussed with supporting hardware results to verify the general structure. The proposed family of converters can be powered using single source or two sources while having continuous input current in both cases. These high voltage gain dc-dc converters are modular and scalable; making them ideal for harnessing energy from various renewable sources offering power at different levels --Abstract, page iv

Design and implementation a novel single switch high gain DC-DC converter based on coupled inductor with low-ripple input current

A novel high-gain and high-efficiency direct current to direct current (DC-DC) converter is introduced in this paper. The presented converter is suitable for low-voltage renewable energy resources such as photovoltaic (PV) and fuel cell (FC). The existence of series inductance with the input source ensures continuous and low-ramp input current, which is important for extracting maximum power from resources. Using coupled inductor technology and an intermediate capacitor in the suggested converter leads to a high gain voltage. In the presented topology for recovering energy from the leakage inductor, reducing voltage stress on the power switch, and so decreasing overall converter losses, a passive clamp circuit is used. The suitable operation range of duty cycle in the converter, besides the leakage inductor, decreases the problem of reverse recovery in diodes. The low value of the leakage inductor and the low volume and cost of the proposed converter are due to the low turn ratio of the coupled inductor. Details of the operation principles of the proposed converter have been discussed in this paper. The presented simulation and laboratory prototype results verify the theoretical analysis and performance of the suggested topology

A Novel AC-DC Interleaved ZCS-PWM Boost Converter

AC-DC converters with input power factor correction (PFC) that consist of two or more interleaved boost converter modules are popular in industry. PFC is a must in today’s AC-DC converters as their input current must meet harmonic standards set by regulatory agencies. With interleaving, the input current of each module can make to be discontinuous and the size of their input inductors since interleaving can reduce the high ripple in each module and produce a net input current with a ripple that is comparable to that achieved with a single boost converter module with a large input inductor. In high- frequency converters, so as to achieve low harmonic, fast dynamic response, low size, and high-power density the frequency should be increased. The drawback of increasing the switching frequency is increasing the switching losses. This is reason that why soft-switching methods should be used. The focus of the thesis is on zero current switching (ZCS) methods for IGBT converters. The auxiliary switch in the proposed converter is activated whenever a main converter switch is about to be turned off, gradually diverting current away from the switch so that it can turn off with ZCS and eliminate the switching losses. In addition, the auxiliary circuit is designed in a way that it can be activated only when the converter is operating with heavier loads and not used when the converter is operating with light load to maximize the overall efficiency. The operation of the novel converter will then be explained and the mathematical analysis in steady-state will be derived. Based on the results of the analysis, general design guidelines will be provided. Finally, the design procedure will be confirmed by experimental results obtained from the proof of concept prototype