摘要:不間斷電源又稱UPS(Uninterruptible Power Supply)被廣泛應用在敏感負載的保護上,如電腦、網絡服務器、醫療設備、通訊系統等,其為這些負載提供了高質量、高可靠性的純凈電源。功率變換是UPS的核心,變換器是實現功率變換的途徑,它的性能決定了UPS整體的性能。
本文在對UPS的拓撲結構、系統組成和工作原理進行了介紹和分析的基礎上,深入分析了離線式UPS中DC/DC和DC/AC變換器電路,對兩種變換器常用的拓撲結構進行了分析和比較,并較詳盡的分析和比較了電壓型和電流型控制技術。在比較分析之后,本設計采用推挽拓撲組成DC/DC變換器電路,這種拓撲結構與橋式和其他拓撲結構相比,其電路簡單、功率MOSFET的數量少,能有效降低電路對變壓器的要求,減少制作成本;在DC/AC變換器電路中,采用典型的橋式拓撲并由系統單片機直接進行控制,其電路輸出功率大、控制簡單、性能優良,有效的提高了輸出電壓的穩定性。
本設計按照模塊化的設計思想,給出了各個部分電路的設計思路和硬件原理圖,并進行了詳細的理論設計和實驗測試。本文闡述的設計思想具有一般性,可以推廣到實際工程應用中。
關鍵字:UPS DC/DC變換器 DC/AC變換器 推挽拓撲
Abstract: The UPS(Uninterruptible Power Supply)is comprehensive used for protecting sensitive loads, such as personal computers, net servers, medical equipments and communication systems. Power transform is the most important part of UPS system, and it must be use Converter and Inverter which capability affecting system’s performance.
Base on the introduction of UPS topology, system’s constitute and the work principle, this paper showing the Off-Line UPS’s Converter and Inverter circuit in details, and analyze each topology’s advantages and disadvantages. We choose the PUSH-PULL topology to makeup Converter circuit after particular analyze. Compare with the bridge or other topology, PUSH-PULL use less MOSFET, easy control and can reduce the request of the transformer. And we use the typical Full-Bridge topology to makeup Inverter circuit which controlled by the system’s MCU. This circuit’s high performance can enhance the whole system’s performance effective and enhance the stability of the output voltage.
This paper showing each circuit’s schematic of design and describing the basic reliability design technologies for Converter and Inverter, it’s design ideology is typical and can use in practical engineering.
Key words: UPS, Converter, Inverter, Push-Pull