Browse Prior Art Database

Integrated Battery/Converter Uninterruptible Power Systems Function

IP.com Disclosure Number: IPCOM000035636D
Original Publication Date: 1989-Jul-01
Included in the Prior Art Database: 2005-Jan-28
Document File: 2 page(s) / 37K

Publishing Venue

IBM

Related People

Johnstone, WV: AUTHOR

Abstract

To optimize the life of the back-up battery used in Uninterruptible Power Systems (UPSs), the battery's charging voltage must be well regulated and conform to the battery's charging characteristics. In some UPSs, a converter is added to perform this function. These systems, shown in Fig. 1, now contain a principle converter, whose function is to provide output power, and a second converter to charge the battery. The added converter function adds to the system cost and degrades its reliability.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 54% of the total text.

Page 1 of 2

Integrated Battery/Converter Uninterruptible Power Systems Function

To optimize the life of the back-up battery used in Uninterruptible Power Systems (UPSs), the battery's charging voltage must be well regulated and conform to the battery's charging characteristics. In some UPSs, a converter is added to perform this function. These systems, shown in Fig. 1, now contain a principle converter, whose function is to provide output power, and a second converter to charge the battery. The added converter function adds to the system cost and degrades its reliability.

To overcome these disadvantages, some systems connect the back-up battery to the principle converter charging function. In this configuration (Fig. 2), whenever the battery sources output power, the output (battery) voltage has a significant droop due to the high internal resistance of the battery. As a result, the output voltage regulation is degraded, even though the converter itself is capable of providing tight regulation.

The scheme which will be described alleviates the necessity for an additional converter, does not degrade the output voltage of the principal converter, and provides a regulated charging voltage for the back-up battery.

In the topology illustrated in Fig. 3, the circuitry connected to the transformer's primary (Np) and the output winding (No) performs the normal output voltage regulation function; in fact, they are the UPS's principal converters. The functions F1 and F2 connected to t...