UPS的设计后备式不间断电源的设计.doc

后备式不间断电源的设计 摘　要 随着电力电子技术的发展，提供更高质量的电能成为可能。不间断电源几乎成为一些行业的必然选择，比如信息业界。不间断电源内置蓄电池，在电网电源中断时，利用蓄电池继续给负载供电，保持负载供电的连续性。 本文详细的介绍了一款小容量的后备式不间断电源的设计方法。此不间断电源包括电池升压电路，电池充电电路，逆变电路，旁路电路等组成。电网正常时，负载直接通过电网供电，当电网断电时，负载由蓄电池供电，实现了电源的不间断。电池升压电路采用隔离型推挽式直流—直流变换电路，其控制核心是UC3825。电池升压电路将24V的蓄电池电压变为400V，为逆变电路提供直流源。逆变电路采用全桥式逆变电路，控制方式采用正弦脉冲宽度调节方式。逆变电路产生220V的交流电压供负载使用。电池充电电路则采用单端反激式开关电源电路，其控制核心是UC3842。此充电电路能实现对蓄电池的分阶段充电。首先以恒定电流对蓄电池快速充电，当蓄电池电压达到一定值时，以恒定电压对蓄电池充电，最后使蓄电池进入浮充模式。另外旁路电路实现电网供电和蓄电池供电的切换。通过检测电网电压，当电网断电时，自动进行切换。本文中设计的电路都用saber进行仿真，以验证其正确性。 The design of off-line UPS Abstract With the development of power electronic technology, it is possible to provide better electronic energy. Uninterruptible power supply almost become the inevitable choice of some industries, such as information industry. There is battery in the uninterruptible power supply. When the power supply is interrupted, the battery supplies power to loads, thus maintaining the continuity of load power supply. This paper introduces the design method of a small-capacity off-line uninterruptible power supply. The uninterruptible power supply includes a battery boost circuit, battery charging circuit, inverter circuit, the bypass circuit and so on. When the power is on, the load is powered directly from the power supply; when the power is off, the load is powered from the battery, thus maintaining the continuity of load power supply. The battery boost circuit is isolated push-pull DC-DC converter circuit, the core of the control circuit is UC3825. Battery boost circuit boosts the battery voltage of 24V to 400V, providing DC source for inverting circuit. The inverter circuit is bridge circuit, the control method is SPWM. The inverter circuit generates an AC 220V for the load. Battery charging circuit uses the flyback switching power supply circuit, the core of the control circuit is UC3842. The charging circuit can charge the battery in different stages. First, battery is charged quickly with a constant current. When the battery vo