This document analyzes a fifth-order resonant converter for high-voltage DC power supplies. It presents a precise analysis of the converter that incorporates the resonant circuit into the transformer model. This derived model can fully predict the behavior of the fifth-order resonant converter. Experimental results on a 10-kVDC, 1.1-kW prototype demonstrate the accuracy of the proposed model and show the converter can operate with zero voltage switching over the entire load range using a fixed-frequency control method.

1. ANALYSIS OF A FIFTH-ORDER RESONANT CONVERTER FOR
HIGH-VOLTAGE DC POWER SUPPLIES
ABSTRACT:
Power transformer is one of the most complex parts of power converters. The complicated behavior
of the transformer is usually neglected in the power converter analysis and a simple model is mostly used to
analyze the converter. This paper presents a precise analysis of a fifth-order resonant converter which has
incorporated the resonant circuit into the transformer. The derived model, which is based on the accurate
model of the power transformer, can fully predict the behavior of the fifth-order resonant converter. The
proposed fifth-order resonant converter is able to effectively reduce the range of phase-shift angle from no
load to full load for a fixed-frequency phase-shift control approach. Therefore, the converter is able to
operate under zero voltage switching during entire load range with a fixed-frequency control method. Also,
the proposed converter offers a high gain which leads to a lower transformer turns ratio. A 10-kVDC, 1.1kW prototype has been prepared to evaluate the performance of the proposed converter. The experimental
results exhibit the excellent accuracy of the proposed model and the superiority of the performance
compared to the lower order resonant converters, especially for high-voltage applications.