摘要 |
<p>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.</p> |