A boost converter with a multiple input and with improved efficiency has two or more inputs. A DC voltage source can be connected to each input. A common output carries a DC voltage whose value is greater than or equal to that of the input voltages. The common output is in each case connected to each of the plurality of inputs via a positive lead branch and a negative lead branch. At least one inductor is arranged in the positive lead branch and/or the negative lead branch from each input, and at least one rectification element is arranged in the positive lead branch and/or the negative lead branch from each input. Furthermore, the inputs can be connected in series by means of two or more switching elements via the inductors, wherein at least two of the inductors can in each case be connected in parallel.

 

CHAPTER ONE
1.1                                                           INTRODUCTION
SWITCHED-MODE step-up dc–dc converters originated with the development of pulse width modulated (PWM) boost converters. Step-up dc–dc topologies convert lower dc voltage levels to higher levels by temporarily storing the input energy and then releasing it into the output at a higher volt- age level. Such storage can occur in either magnetic field storage components (single inductor/coupled inductor) or electric field storage components (capacitors) through the use of various active or passive switching elements (power switches and diodes). With the introduction of semiconductor switches in the 1950s, step-up dc–dc converters achieved steady performance advancements and their use accelerated through the 1960s when semiconductor switches became commercially available with allied manufacturing technologies [1]. The rise of the aerospace and telecommunication industries further extended the research boundaries of boost converters, especially in applications where efficiency, power density, and weight were of major concern. Efficiency has steadily improved since the late 1980s owing to the use of power field-effect transistors (FETs), which are able to switch more efficiently at higher frequencies than power bipolar junction transistors while incurring lower switching losses and requiring a less complicated drive circuit. In addition, the FET replaces output rectifying diodes through the use of synchronous rectification, whose “on resistance” is much lower than and further increases the efficiency of the step-up dc–dc converter, which requires a higher number of diodes for voltage boosting [1]–[3].
A PWM boost converter is a fundamental dc–dc voltage step- up circuit with several features that make it suitable for various applications in products ranging from low-power portable de- vices to high-power stationary applications. The widespread application of PWM boost dc–dc converters has been driven by its low  number of elements, which is a major advantage   in terms of simplifying modeling, design implementation, and manufacturing. The voltage step-up capability of a PWM boost dc–dc converter is enabled by an inductor at the input side that can operate either with a continuous current—in the so-called continuous conduction mode (CCM)—or including a zero cur- rent state in the discontinuous conduction mode (DCM). In general, CCM operation is more prevalent owing to the load dependent voltage gain, high current ripple, and low efficiency.

1.2                                           BACKGROUND OF THE PROJECT
The present invention relates to a boost converter, in particular a boost converter with multiple inputs, and to an inverter circuit having such a boost converter.
Boost converters, which are also referred to as step-up converters, are very frequently used in widely differing types of electrical power supplies. As in all power-electronic assemblies, one aim in this case is to achieve as high an efficiency as possible with costs which are as low as possible.
In order to produce an AC voltage, an inverter generally requires an intermediate-circuit voltage at a specific level. Optimum efficiency is normally achieved when the intermediate-circuit voltage is matched precisely to the AC voltage to be produced.
In general, depending on the light incidence, the temperature and the number of connected modules, solar generators produce a widely fluctuating DC voltage. The broader the range of the input DC voltage which an inverter can process, the more options there are for appropriate module combinations. For example, an input voltage range of 1:2 is desirable for full load, and a range of 1:2.5 is desirable for full load to no load.
A boost converter is therefore frequently used to match the solar generator to the inverter, boosting the variable DC voltage to a relatively constant intermediate-circuit voltage.

1.3                                               OBJECTIVE OF THE PROJECT
The main aim of this work is to construct and simulate an electronic circuit or electromechanical device that converts a source of direct current (DC) from one voltage level to another. It is a type of electric power converter.

1.4                                                PROBLEM OF THE PROJECT
This device has a number of disadvantages:

• High ripple currents occur at the input and output.
• A large inductor is required, since large amounts of energy must be temporarily stored.
• The load on the semiconductors is high.
• The efficiency is poor.

Overall, the use of a boost converter is associated with additional costs, weight and volume. Furthermore, the overall efficiency of the inverter circuit is decreased by the additional losses in the boost converter.

1.5                                            SIGNIFICANCE OF THE PROJECT
DC to DC converters are used in portable electronic devices such as cellular phones and laptop computers, which are supplied with power from batteries primarily. Such electronic devices often contain several sub-circuits, each with its own voltage level requirement different from that supplied by the battery or an external supply (sometimes higher or lower than the supply voltage). Additionally, the battery voltage declines as its stored energy is drained. Switched DC to DC converters offer a method to increase voltage from a partially lowered battery voltage thereby saving space instead of using multiple batteries to accomplish the same thing.
Most DC to DC converter circuits also regulate the output voltage. Some exceptions include high-efficiency LED power sources, which are a kind of DC to DC converter that regulates the current through the LEDs, and simple charge pumps which double or triple the output voltage.
DC to DC converters developed to maximize the energy harvest for photovoltaic systems and for wind turbines are called power optimizers.

1.6                                                   SCOPE OF THE PROJECT
This paper presents a DC-DC converter system. The proposed converter comprises of an input-current doubler, an output-voltage doubler, and an active-clamp circuit. The input-current doubler and the output-voltage doubler both provide much higher voltage conversion ratio by using a low turn ratio transformer. The low turns ratio increases the overall efficiency. A series resonant circuit of the output voltage doubler removes the reverse recovery problem of the rectifying diodes. The active-clamp circuit clamps the surge voltage of switches and recycles the energy stored in the leakage inductance of the transformer.

1.7                                                    AREA OF APPLICATION
This device is used in small voltage appliances to multiply their input and output voltages such as in:

• cellular phones
• laptop computers
• fuel cells,
• photovoltaic (PV) cells,
• and wind power, etc

1.8                                                    DEFINITION OF TERMS
Step-down: A converter where output voltage is lower than the input voltage (such as a buck converter).
Step-up: A converter that outputs a voltage higher than the input voltage (such as a boost converter).
Continuous current mode: Current and thus the magnetic field in the inductive energy storage never reach zero.
Discontinuous current mode: Current and thus the magnetic field in the inductive energy storage may reach or cross zero.
Noise: Unwanted electrical and electromagnetic signal noise, typically switching artifacts.
RF noise: Switching converters inherently emit radio waves at the switching frequency and its harmonics. Switching converters that produce triangular switching current, such as the Split-Pi, forward converter, or Ćuk converter in continuous current mode, produce less harmonic noise than other switching converters.[17] RF noise causes electromagnetic interference (EMI). Acceptable levels depend upon requirements, e.g. proximity to RF circuitry needs more suppression than simply meeting regulations.
Input noise: The input voltage may have non-negligible noise. Additionally, if the converter loads the input with sharp load edges, the converter can emit RF noise from the supplying power lines. This should be prevented with proper filtering in the input stage of the converter.
Output noise: The output of an ideal DC-to-DC converter is a flat, constant output voltage. However, real converters produce a DC output upon which is superimposed some level of electrical noise. Switching converters produce switching noise at the switching frequency and its harmonics. Additionally, all electronic circuits have some thermal noise. Some sensitive radio-frequency and analog circuits require a power supply with so little noise that it can only be provided by a linear regulator. Some analog circuits which require a power supply with relatively low noise can tolerate some of the less-noisy switching converters, e.g. using continuous triangular waveforms rather than square waves.

---

This material is a complete and well researched project material strictly for academic purposes, which has been approved by different Lecturers from different higher institutions. We make abstract and chapter one visible for everyone.

All Project Topics on this site have complete 5(five) Chapters . Each Project Material include: Abstract + Introduction + etc + Literature Review + methodology + etc + Conclusion + Recommendation + References/Bibliography.

To "DOWNLOAD" the complete material on this particular topic above click "HERE"

Do you want our Bank Accounts? please click HERE

To view other related topics click HERE

To "SUMMIT" new topic(s), develop a new topic OR you did not see your topic on our site but want to confirm the availiability of your topic click HERE

Do you want us to research for your new topic? if yes, click "HERE"

Do you have any question concerning our post/services? click HERE for answers to your questions

You can also visit our facebook Page at fb.me/hyclas to view more our related construction (or design) pics

---

For more information contact us through Any of the following means:

Mobile No :+2348146561114 or +2347015391124 [Mr. Innocent]

Email address :engr4project@gmail.com

Watsapp No :+2348146561114

To View Our Design Pix: You can also visit our facebook Page at fb.me/hyclas for our design photos/pics.

---

IF YOU ARE SATISFIED WITH OUR SERVICES, PLEASE DO NOT FORGET TO INVITE YOUR FRIENDS AND COURSEMATES TO OUR PAGE.