Methods and apparatus for providing protection to batteries in an uninterruptible power supply
First Claim
1. An uninterruptible power supply for providing continuous power to a critical load, said uninterruptible power supply comprising:
- an AC-to-DC converter circuit having an input coupled to a source of primary power, and an output;
a DC-to-AC converter circuit having an input coupled to said output of said AC-to-DC converter circuit to form a DC buss, and an output;
a battery bank;
a first monitoring circuit that monitors for an extended outage of primary power;
a flywheel energy storage unit electrically coupled to said DC buss, said flywheel unit providing power in the event of short duration outages of primary power; and
a first isolation circuit coupled to receive information from said first monitoring circuit regarding status of primary power, said first isolation circuit being coupled between said battery bank and said DC buss, said first isolation circuit being triggered to switch out of isolation when said extended outage of primary power is detected so that said battery bank is then directly coupled to said DC buss to provide power to said buss.
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Accused Products
Abstract
An uninterruptible power supply (UPS) provides improved reliability by extending the useful life of a bank of batteries that provide backup power to the UPS in the event of an extended power outage. In the preferred embodiment, battery life is extended by switchably isolating the bank of batteries from the DC buss that is coupled to the critical load. Backup power for short duration outages, on the order of about ten seconds or less, is provided by a flywheel energy storage unit. Once the outage becomes extended, the isolation circuit is triggered to electrically connect the bank of batteries directly to the DC buss. In this manner, the bank of batteries does not experience AC ripple or the common, short duration outages that would otherwise cause the batteries to experience a discharge/recharge cycle.
115 Citations
27 Claims
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1. An uninterruptible power supply for providing continuous power to a critical load, said uninterruptible power supply comprising:
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an AC-to-DC converter circuit having an input coupled to a source of primary power, and an output; a DC-to-AC converter circuit having an input coupled to said output of said AC-to-DC converter circuit to form a DC buss, and an output; a battery bank; a first monitoring circuit that monitors for an extended outage of primary power; a flywheel energy storage unit electrically coupled to said DC buss, said flywheel unit providing power in the event of short duration outages of primary power; and a first isolation circuit coupled to receive information from said first monitoring circuit regarding status of primary power, said first isolation circuit being coupled between said battery bank and said DC buss, said first isolation circuit being triggered to switch out of isolation when said extended outage of primary power is detected so that said battery bank is then directly coupled to said DC buss to provide power to said buss. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. A method of extending useful life of a bank of batteries in an uninterruptible power supply, said method comprising the steps of:
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converting AC power from a primary source to DC power; outputting said DC power to a DC buss; monitoring the voltage level of power in said uninterruptible power supply with a first monitoring circuit; providing backup power to said DC buss from a flywheel storage unit in the event of a short duration loss of power from said primary source; coupling a first switchable isolation circuit between said bank of batteries and said DC buss; and triggering said first isolation circuit to couple said bank of batteries to said DC buss in the event of an extended loss of power from said primary source. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25, 26, 27)
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Specification