Design And Construction Of A Wireless AC Power Transfer Using High Frequency

ABSTRACT

As power requirements for portable devices increase, consumers are looking for easy-to-use charging solutions that can be deployed in a wide array of environments such as home, office, automobiles, airports, schools and more. An AC Wireless power transfer uses an electromagnetic field to transfer energy between two objects. This is usually done with a charging station.  Energy is sent through an inductive coupling to an electrical device, which can then use that energy to run the devices.

TABLE OF CONTENTS

 TITLE PAGE

APPROVAL PAGE

DEDICATION

ACKNOWLEDGEMENT

ABSTRACT

TABLE OF CONTENT

CHAPTER ONE

• INTRODUCTION
• AIM/OBJECTIVE OF THE PROJECT
• PURPOSE OF THE PROJECT
• SIGNIFICANCE OF THE PROJECT
• LIMITATION OF THE PROJECT
• APPLICATION OF THE PROJECT
• BENEFIT OF THE PROJECT
• SCOPE OF THE PROJECT
• PROBLEM OF THE PROJECT
• PROJECT ORGANISATION

CHAPTER TWO

2.0     LITERATURE REVIEW

2.1     LITERATURE REVIEW OF THE STUDY

2.2     HISTORICAL BACKGROUND OF INDUCTION

2.3      REVIEW INDUCTIVE (MAGNETIC) COUPLING

2.4     GENERAL APPLICATION OF AN INDUCTIVE COUPLING

2.5     OVERVIEW OF AN INDUCTOR

2.6     INDUCTOR CONSTRUCTION REVIEW

2.7     INDUCTOR CONSTRUCTION REVIEW

 CHAPTER THREE

3.0     CONSTRUCTION METHODOLOGY

3.1      SYSTEM BLOCK DIAGRAM

3.3      DESCRIPTION OF SYSTEM BLOCK DIAGRAM

3.4      SYSTEM CIRCUIT DIAGRAM

3.4.1  TRANSMITTING CIRCUIT

3.4.2  RECEIVING CIRCUIT

3.5      CIRCUIT OPERATION

3.6      CIRCUIT DESCRIPTION

3.6      DESCRIPTION OF ELECTRONICS COMPONENTS USED

CHAPTER FOUR

RESULT ANALYSIS

4.0      CONSTRUCTION PROCEDURE AND TESTING

4.1      CASING AND PACKAGING

4.2      ASSEMBLING OF SECTIONS

4.3      TESTING OF SYSTEM OPERATION

4.4      COST ANALYSIS

CHAPTER FIVE

5.0      CONCLUSION

5.1      RECOMMENDATION

5.2      REFERENCES

CHAPTER ONE

• INTRODUCTION

Inductive power transfer (also known as wireless power transfer) uses an electromagnetic field to transfer energy between two objects. This is usually done with a charging station. Energy is sent through an inductive coupling to an electrical device, which can then use that energy to charge batteries or run the device.

This device use an induction coil to create an alternating electromagnetic field from within a charging base, and a second induction coil in the portable device takes power from the electromagnetic field and converts it back into electric current to charge the battery. The two induction coils in proximity combine to form an electrical transformer. Greater distances between sender and receiver coils can be achieved when the inductive charging system uses resonant inductive coupling. Recent improvements to this resonant system include using a movable transmission coil (i.e. mounted on an elevating platform or arm) and the use of other materials for the receiver coil made of silver plated copper or sometimes aluminium to minimize weight and decrease resistance due to the skin effect.

1.1                                             OBJECTIVE OF THE PROJECT

The objective of this project is to design a wireless power transmission system using inductive coupling is to charge a low power device using wireless power transmission. This is done using charging a resonant coil from AC and then transmitting subsequent power to the resistive load at higher frequency (converting 50 Hz to 26 kHz). The project is meant to power device quickly and efficiently by inductive coupling without the help of wires.

1.2                                              PURPOSE OF THIS PROJECT

The main purpose of this project is to transfer the AC power wirelessly from a power source to electrical loads using a high! Frequency resonating air core transformer to develop the frequency from 50hz to 26khz for transferring power over a distance of 3cm.

1.3                                         SIGNIFICANCE OF THE PROJECT

• Protected connections – No corrosion when the electronics are all enclosed, away from water or oxygen in the atmosphere. Less risk of electrical faults such as short circuit due to insulation failure, especially where connections are made or broken frequently.
• Low infection risk – For embedded medical devices, transmission of power via a magnetic field passing through the skin avoids the infection risks associated with wires penetrating the skin.
• Durability – Without the need to constantly plug and unplug the device, there is significantly less wear and tear on the socket of the device and the attaching cable.
• Increased convenience and aesthetic quality – No need for cables

1.4                                           LIMITATION OF THE PROJECT

• Slower when using as charging device – Due to the lower efficiency, devices take longer to charge when supplied power is the same amount.
• More expensive – Inductive charging also requires drive electronics and coils in both device and charger, increasing the complexity and cost of manufacturing.
• Inconvenience – When a mobile device is connected to a cable, it can be freely moved around and operated while charging. In most implementations of inductive charging, the mobile device must be left on a pad to charge, and thus can’t be moved around or easily operated while charging.
• Incompatibility – Unlike (for example) a MicroUSB charging connector, there are no universal standards for inductive charging, thus necessitating various different chargers for different devices. Newer approaches reduce transfer losses through the use of ultra thin coils, higher frequencies, and optimized drive electronics. This results in more efficient and compact chargers and receivers, facilitating their integration into mobile devices or batteries with minimal changes required. These technologies provide charging times comparable to wired approaches, and they are rapidly finding their way into mobile devices.
• Distance constraint: Field strengths have to be under safety levels
• Initial cost is high
• In RIC, tuning is difficult
• High frequency signals must be the supply Air ionization technique is not feasible

1.5                                         APPLICATIONS OF THE PROJECT

• Industrial Applications: Wireless power transfer has seen tremendous applications and value addition to industries. The primary applications include wireless sensors on rotating shafts, wireless equipment charging and powering, and safe and watertight equipment through eliminating charging cords
• Subsea applications: though subsea vehicles can self-navigate, human assistance is still required for power supply. Due to the rough terrain, as well as the distance, cabled conductors can prove to be a challenge. WPT comes in handy in these instances.
• Charging mobile devices, unmanned aircraft, home appliances and electric vehicles: The charging system the smaller gadgets comes in the form of a charging pad and power benches, where the user places the device such as a mobile phone and electric toothbrushes.
• Charging and operating medical implants such as subcutaneous drug supplies, pacemakers, and other implants. WPT, especially with high resonance allows convenient continual charging of these implants without the need for frequent surgeries and the inclusion of external charging ports.
• Charging wearables: The convenience of wearables lies in the mobility and convenience. Considering that the wearer has to walk around, the primary problem thus is the charging. Wireless power transfer accords the convenience of charging by eliminating the requirement for cables and connectors
• Near-field energy transfer
• Electric automobile charging Static and moving
• Consumer electronics
• Industrial purposes Harsh environment Far-field energy transfer
• Solar Power Satellites
• Energy to remote areas
• Can broadcast energy

1.6                                              BENEFITS OF THE PROJECT

• Allows for charging of multiple devices. This is achieved by changing the coil geometry, as well as allocating large charging surface areas such as table tops and charging benches.
• High charging speeds: though at the moment wireless charging offers a slower charging rate than the wired option, advances in resonance and induction technology promises an increased charging rate and improved efficiency in the future
• Wireless power transfer allows for greater spatial freedom between the power source and the device. This means that the two do not have to be precisely aligned for power transfer.
• Eliminating charging cords enables engineers to make compact and watertight devices, thus maximizing on safety, and varied use such as in deep-sea applications.
• Prevents corrosion and sparking by eliminating mechanical connectors and wired contacts
• Reduces costs associated with maintaining and replacing mechanical connectors.

1.7                                                 SCOPE OF THE PROJECT

Wireless charger using inductor (coil), is one of the effective ways to transfer power between points without the use of conventional wire system. Wireless power transmission is effective in areas where wire system is unreachable or impossible. The power is transferred using inductive coupling, resonant induction or electromagnetic wave transmission depending on whether its short range, mid-range or high range.

In this project, the wireless power transfer works mainly on the principle of inductive coupling, using inductor at the transmitting and receiving side of the circuits. With this inductive coupling idea, we are trying to transfer power wirelessly to charge low power devices, such as mobile phones, cameras, wireless mouse etc.

1.8                                              PROBLEM OF THE PROJECT

During the construction we faced a challenge; the strength of a magnetic field decreases with distance. The decrease in strength is proportional to the square of the distance from the source. This made it difficult to regulate power and reduced energy efficiency.

1.9                                        PROJECT WORK ORGANISATION

The various stages involved in the development of this project have been properly put into five chapters to enhance comprehensive and concise reading. In this project thesis, the project is organized sequentially as follows:

Chapter one of this work is on the introduction to this study. In this chapter, the background, significance, objective, limitation, application and scope of this study were discussed.

Chapter two is on literature review of this study. In this chapter, all the literature pertaining to this work was reviewed.

Chapter three is on design methodology. In this chapter all the method involved during the design and construction were discussed.

Chapter four is on testing analysis. All testing that result accurate functionality was analyzed.

Chapter five is on conclusion, recommendation and references.