Energy encryption for medium field of wireless power transfer system

Abstract

Nowadays, the wireless power transfer (WPT) on mobile charging application of power transfer is the process of transferring power using WPT technology are progressing rapidly. The launching of more mobile embedded with WPT system make it as currently most demanding technology. In WPT, the main issue that being investigated are focused on power transfer efficiency (PTE), effective distance and the size of transmitter and receiver itself. Apart from that, the security of the power transfer is very important from transmitter to selected receiver must be completely secure. The failure to secure WPT system has affected the process to transfer power from transmitter to correct receiver. This thesis presents method which manipulates chaos theory to ensure the security of energy is encrypted to transfer and recovered as security at the correct receiver efficiently with higher security. In chaos theory technique, there are chaotic behaviour element which being embedded using the logistic map and Lyapunov exponent for additional security with matching the switching frequency of the transmitter and receiver. Chaotic behaviour is triggered on each characteristic which are Lyapunov exponent, logistic map and switching frequency. For this research, the application of WPT is focused on mobile charging application and its security efficiency is tested through chaos theory. Thus, detailed study is carried out by varying the power operation, distance of effective PTE and the capacitor combination. The system is simulated using MATLAB programming by creating and simulating WPT environment. The simulation took all the characteristic and specification of mobile charging application which is resides within medium field range. The operating frequency is around 100 kHz, operating power of 10 W and distance are adjusted from 3 cm to 5 cm. The simulation is done by sample taking into account that characteristic of chaos theory which are logistic map, Lyapunov exponent, matching switching frequency and matching security key. Lyapunov exponent which triggered the matching frequency process must be greater than 3.50. As for this research, the Lyapunov exponent value is chosen by random and it is greater than 3.50. The sampling result shows that, the power is securely transferred by the following data: delivered power of 10 W, matching frequency of 102 kHz (±2% at 100 kHz) and matching security key for transmitter and receiver of 1.02 and 0.86 respectively. As the conclusion, results show that chaos theory technique is effectively employed for security of energy encryption process. It also managed to transfer energy from a transmitter to the intended receiver. This is proven by the utilization of chaos theory technique of transmitter encrypted power at distance of 4 cm between the transmitter and receiver.