Study of Soft-Switched technology in Uninterruptible Power Supply

• Main Authors: Chang, Yu-Ming, 張育銘
• Other Authors: Lee Jia-You
• Format: Others
• Language: zh-TW
• Published: 1998
• Online Access: http://ndltd.ncl.edu.tw/handle/85503124585230300732

博士 === 國立成功大學 === 電機工程學系 === 86 === In this dissertation, the goal is to implement the UPS product trend by using soft-switched technology. Due to the complex structure of the on-line UPS, the penetration is located in researching of non-isolated PFC converter, isolated PFC converter and DC/DC converter and DC/AC inverter. For non- isolated soft-switched boost converter, the study has found a resonant tank to achieve the zero-voltage switching of the main switches and also proposed a control scheme for reducing the circulating loss. For isolated soft-switched boost converter, the study was proposed a new soft-switched topology which can achieved the goals of light weight, small size, high conversion efficiency and low cost. And, the analysis, design and control of the proposed isolated soft-switched boost converters were presented and experimental results weresubmitted for verification.Regarding to soft-switched DC/DC converters, a new ideal for implementing soft-switched technologies was proposed, by replacing the original PWM switch with proposed H-soft- switch. ThisH-soft-switched cell can obtain soft switching in single-switch non-isolatedDC/DC converter and provides constant- frequency loss-less switching. It maybe regarded as a soft- switch with a similar control circuit to that used in conventional PWM converters. Based on an equal area concept, a unified methodfor steady-state analysis is also proposed. The concept of equivalent dutyis introduced to simplify the design of the converters. In Chapter 6, a novel high-frequency-link UPS topology is proposed which using the soft-switchedtechnologies and integrating the charger in the DC/DC converter, the experimental results show the proposed UPS has a high-degree of efficiencyincreasing, cost reducing, size reducing and weight reducing. It is verysuitable for long backup-time UPS requirement, as the DC/DC converter cansatisfy the charging requirement of the long backup batteries.