High efficiency resonant switched capacitor converter with continuous conversion ratio

Abstract

A power converter, which comprises a resonant Switched Capacitor Converter (SCC) that consists of an input connected to an input voltage source, from which power is delivered to a load; a resonant tank circuit formed by a capacitor connected in series with an inductor and defining a resonant cycle; a first switch connected in series between a first contact of the input voltage source and a first contact of the resonant tank circuit; a second switch connected in series between the first contact of the resonant tank circuit and a first contact of the load; a conducting path connecting between a second contact of the input voltage source, a second contact of the resonant tank circuit and a second contact of the load and a third switch connected in parallel to the resonant tank circuit. The converter is adapted to charge the resonant tank circuit by controlling the first switch to start conducting at a first zero crossing point and allow current to flow from the input voltage source to the tank circuit during a first portion of the cycle; discharge the resonant tank circuit into the load by controlling the first switch to stop conducting and the second switch to start conducting, at a second zero crossing point to thereby allow current to flow from the tank circuit to the load during a second portion of the cycle, and reverse the voltage polarity on the capacitor by controlling the second switch to stop conducting and the third switch to start conducting at a third zero crossing point during the last portion of the cycle.