Transmissão de energia elétrica sem fios através de acoplamento indutivo ressonante utilizando conversor CC-CA

Abstract

The present work presents the development and the implementation of a system that performs the transmission of electric energy wirelessly, from one point to another, using the method inductive resonant coupling. The power transmission system consists of a five-level, symmetrical cascaded AC-DC converter, powered by two continuous, ideal sources with resonant charge for transmitting. The converter uses MOSFETs as semiconductor switches and these were driven via software through a CPLD (Complex Programmable Logic Device). The receiver circuit consists of a resonant LC followed by a voltage rectifier connected to a load. The resonant circuits are composed of planar coils with circular geometries, handcrafted with Litz Wire and capacitors. The system is designed to operate with fixed frequencies within the range of 30 to 100 kHz and is evaluated for four distinct topologies of resonant circuits (SS, SP, PS and PP) at four different transmission distances (0, 1, 2 and 3 cm), in which the energy efficiency levels generated by each topology are quantified. The tests performed show that the topology PP presents superior performance to other topologies, reaching up to 83.3% efficiency with the system submitted to 30 kHz and minimum transmission distance (best case studied). In this case, the SS topology is indicated as the least efficient, reaching only 47.2%. The entire system is constructed so as to enable the exchange of components related to resonant frequency manually and without risk of damage to the system or to the user.