Theoretical Analysis of Decreased Boost Ratio in Unloaded Cockcroft-Walton Circuit

Abstract

The Cockcroft-Walton (CW) circuit, which is well known as a high step-up converter, is used in a lot of systems. It is conventionally considered that the boost ratio of the circuit decreases according to the load current. However, the boost ratio decreases also under unloaded conditions. In the study, the reason for the boost ratio decrease in the unloaded CW circuit is investigated. The theoretical results show that the diode's junction capacitors cause the boost ratio to decrease. In addition, it is numerically and experimentally clarified that the theoretical results are valid.