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. Wireless charging 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. Experimental results demonstrate the feasibility and effectiveness of the proposed WPT system, achieving an efficiency of 85% over a distance of 25 cm. The system is capable of transferring power up to 100 watts, making it suitable for a wide range of applications, including consumer electronics, medical devices, and electric vehicles. The proposed WPT system offers several advantages over traditional wired power transfer methods, including convenience, safety, and efficiency. The system eliminates the need for cables and connectors, reducing the risk of electrical shock and fires. Additionally, the system is highly efficient, reducing energy losses and heat generation. The project explores the potential applications of WPT technology in various fields, including consumer electronics, medical devices, and electric vehicles. Wireless charging of smartphones, laptops, and tablets, as well as wireless power transfer for implantable devices and electric vehicles, are some of the potential applications.
CHAPTER ONE
INTRODUCTION
1.1 Background of the Project
Inductive power transfer (also known as wireless power transfer) uses an electromagnetic field to transfer energy between two objects [1]. 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 aluminum to minimize weight and decrease resistance due to the skin effect.
1.2 Problem Statement
In wireless power transfer systems, optimizing the performance of the energy transfer process through coils involves several critical factors. These include ensuring efficient energy transfer despite varying distances between the coils, managing the mutual inductance and impedance matching, and operating the system effectively across different frequencies. Current systems often face issues with power loss, limited transfer range, and suboptimal efficiency due to inadequate coil design and system configuration.
1.3 Objective of the Project
The objective of this project is to design a wireless power transmission system using inductive coupling to charge a low power device. This is done using charging a resonant coil from AC and then transmitting subsequent power to the resistive load. The project is meant to charge a low power device quickly and efficiently by inductive coupling without the help of wires.
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 Micro-USB 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
Air ionization technique is not feasible, because it requires high frequency signal