Single-Phase Resonant $LC$ Circuit Using a Bank of Self-Switched Capacitors

This paper presents a preliminary work on the feeding of an ac dipole using a resonant circuit with a varying resonant frequency. A single-phase LC oscillator containing a variable capacitor is fed by a wideband amplifier or a voltage source inverter. For this purpose, a bank of switched capacitors of different values are connected to the main circuit through bidirectional switches. In order to allow zero-current and zero-voltage switchings, the devices are implemented with close-control driver circuits, allowing self-switching based on local polarity measurements. An innovative controller for maintaining the current in an oscillator and a regressive method for measuring alternating current with a limited number of samples are proposed and validated by experiment.