摘要 |
A uninterruptible power system in which separate inverters are connected to separate d.c. power sources established by independent power supplies, a.c., d.c. or both, and have their a.c. outputs connected to separate transformer primary windings with the primary to secondary turns ratios of the primary windings establishing different effective secondary voltages for determining the power source for normally supplying the power from the system and the sequence in which the other power sources are used on power failure, the magnitudes of the effective voltages determining the power source for initially supplying the power with any other power source supplying the power when its effective voltage is higher than any other available power source.
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