A Novel Switched Capacitor DC-AC Converter with Hysteresis Control

Switched Capacitor Converter (SCCs) for DC-AC conversion is an area of keen interest owing to their benefits and application in many diverse fields related to renewable energy technology. SC-based inverters have advantages such as step-up voltage capability, operating without output side filters, compact design and higher power density. This paper proposes a novel SC-based DC-AC converter with a unique control architecture to achieve AC power at the output. The control architecture utilizes a hysteresis control to track the capacitor voltages to reference and achieve a step-up gain in the output voltage. The proposed converter enables an inherent output voltage ripple reduction by nearly interleaving the charging-discharging phases of the capacitors. Thus, the total harmonic distortion (THD) on the load current is much less.It also eliminates the use of output side magnetic filtering elements and hence removes the drawbacks associated with it. The paper discusses the topology, the control architecture and the challenges involved in optimizing various parameters for the desired operation.