Wireless power transfer (WPT) is a method of transmitting power without using cables or wires. The application of WPT has been widely applied in various sectors such as biomedicals, telecommunications, and transportation. However, the efficiency of WPT system is very dependent on the distance between transmitter and receiver coils. The farther distance between the coils, the lower power can be transferred, and vice versa.
Therefore, the objective of this research is to get an improvement in power of 5 kHz WPT system by designing circular planar spiral coils to obtain a suitable inductance value for the matching frequency of 5 kHz. Furthermore, the system is constructed and simulated by adding a multi-magnetic circular planar spiral relay. The WPT performance is then evaluated and validated based on simulations and experiments with an error percentage of less than 10%. The WPT system in this research consists of three main components. The three components are a DC voltage source, transmitter circuit, and receiver circuit. The transmitter circuit is constructed by pulse driver, full bridge inverter and coil, where the main DC voltage source is converted by the inverter circuit into AC voltage and then to be connected to the transmitter coil based on the principle of inductive coupling. The construction of the coils has been constructed based on the shape and value of the desired coil inductance at 337.4 µH by taking into account the values of N, din, dout, dw, and s. Furthermore, the proposed coil is also used as a multi-magnetic circular planar spiral relay to strengthen the mutual inductance between transmitter and receiver coils. This research is simulated using PSIM software and experiments using hardware that has been developed using the proposed coils. The positions of the transmitter coil, receiver coil, and multi-magnetic relay are set at certain distances to observe the power improvement that occurs after the multi-magnetic relay is added to the system. As the result, the power received at the receiver coil with given Vdc = 30 V and dtr = 21 cm can be increased up to 67%. Research conducted on simulations and experiments has been evaluated and validated with the percentage errors obtained are less than 10%.
