SPRS881K August 2014 – February 2024 TMS320F28374S , TMS320F28375S , TMS320F28375S-Q1 , TMS320F28376S , TMS320F28377S , TMS320F28377S-Q1 , TMS320F28378S , TMS320F28379S
PRODUCTION DATA
Refer to the PDF data sheet for device specific package drawings
Uninterruptible power supplies (UPS) play an important role in interfacing critical loads such as computers, communication systems, medical/life support systems, and industrial controls to the utility power grid. They are designed to provide clean and continuous power to the load under essentially any normal or abnormal utility power condition. Among the various UPS topologies or configurations, on-line UPS, also known as inverter-preferred UPS, offers the best line-conditioning performance and the most protection to the load against any utility power problems. It provides regulated sinusoidal output voltage under any input line condition. When powered from the utility power lines, it draws sinusoidal input current at a high input power factor. These improved input/output characteristics make on-line UPS the ideal solution in many applications.
A triple conversion on-line UPS system is shown in Figure 8-7. The power factor correction (PFC) input stage is an ac-to-dc converter, which rectifies the input Vac and creates the dc bus voltage while maintaining sinusoidal input current at a high input power factor. The PFC stage also regulates the dc bus voltage against variation in input Vac. The dc bus voltage is inverted through the output dc-to-ac inverter stage to generate the output Vac of appropriate frequency. A dc-to-dc buck converter stage implements the battery charger. The battery charger stage steps down the high dc bus voltage (up to 400 V) to allow a smaller battery to be charged. A dc-to-dc boost converter raises the battery voltage up to the bus voltage when the system is operating in battery backup mode.