Hybrid Resonant Converter with Three Half-Bridge Legs for Wide Voltage Operation

Bor-Ren Lin,Yong-Sheng Zhuang

doi:10.3390/app10010310

Bor-Ren Lin, Yong-Sheng Zhuang

Open Access

https://doi.org/10.3390/app10010310

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Abstract

This paper studied a hybrid resonant converter with three half bridge legs for wide input voltage operation. Compared to the conventional resonant converters with narrow voltage operation, the presented converter can achieve wider voltage operation. On the basis of the proper switching status of power switches, the developed converter can operate at half-bridge resonant circuit under high input voltage range and the other two full-bridge resonant circuits under medium and low input voltage ranges. Each resonant circuit has a 2:1 (Vin,max = 2Vin,min) input voltage operation range. Therefore, the developed converter can achieve an 8:1 (Vin,max = 8Vin,min) wide voltage operation. The main advantage of the studied converter is the single-stage direct current (DC)/DC power conversion instead of the two-stage power conversion to achieve wide voltage operation. Because the equivalent resonant tank of the adopted converter is controlled by frequency modulation, the soft switching operation on power switches or rectifier diodes can be realized to improve circuit efficiency. The performance of the proposed circuit was confirmed and verified by experiments with a laboratory circuit.

Highlights

Because the equivalent resonant tank of the adopted converter is controlled by frequency modulation, the soft switching operation on power switches or rectifier diodes can be realized to improve circuit efficiency
Power electronic converters with high efficiency are developed for consumer electronics, battery chargers, telecommunication power units, direct current (DC) nano-grid power conversions, internet of things (IOT) power units, and renewable energy conversions
If Vin is under medium voltage range from 100 to 200 V, the sub-circuit with full bridge circuit topology and high turns ratio transformer is operated to decrease the voltage gain in order to control the load voltage

Summary

Introduction

Power electronic converters with high efficiency are developed for consumer electronics, battery chargers, telecommunication power units, direct current (DC) nano-grid power conversions, internet of things (IOT) power units, and renewable energy conversions. If the much wider voltage range is requested, such as Vin,max ≥ 4Vin,min in solar panel applications or wide voltage variation systems, these circuit topologies cannot be operated well. On the basis of the switching status of active switches, the proposed resonant converter has three equivalent sub-circuits to implement 8:1 (Vin,max = 8Vin,min ) wide voltage range operation such as 50–400 V. If Vin (input voltage) is under low voltage range from 50 to 100 V, the sub-circuit with the full bridge circuit topology and low turns ratio transformer is operated to have high voltage gain. If Vin is under medium voltage range from 100 to 200 V, the sub-circuit with full bridge circuit topology and high turns ratio transformer is operated to decrease the voltage gain in order to control the load voltage. The design procedures and experiments are presented and confirmed with a 480 W laboratory circuit

Circuit Structure and Principle of Operation

Design Procedures and Test Results

Findings

Conclusions