摘要:不间断电源又称UPS(Uninterruptible Power Supply)被广泛应用在敏感负载的保护上,如电脑、网络服务器、医疗设备、通讯系统等,其为这些负载提供了高质量、高可靠性的纯净电源。功率变换是UPS的核心,变换器是实现功率变换的途径,它的性能决定了UPS整体的性能。
本文在对UPS的拓扑结构、系统组成和工作原理进行了介绍和分析的基础上,深入分析了离线式UPS中DC/DC和DC/AC变换器电路,对两种变换器常用的拓扑结构进行了分析和比较,并较详尽的分析和比较了电压型和电流型控制技术。在比较分析之后,本设计采用推挽拓扑组成DC/DC变换器电路,这种拓扑结构与桥式和其他拓扑结构相比,其电路简单、功率MOSFET的数量少,能有效降低电路对变压器的要求,减少制作成本;在DC/AC变换器电路中,采用典型的桥式拓扑并由系统单片机直接进行控制,其电路输出功率大、控制简单、性能优良,有效的提高了输出电压的稳定性。
本设计按照模块化的设计思想,给出了各个部分电路的设计思路和硬件原理图,并进行了详细的理论设计和实验测试。本文阐述的设计思想具有一般性,可以推广到实际工程应用中。
关键字:UPS DC/DC变换器 DC/AC变换器 推挽拓扑
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