1. Field of the Invention
This invention relates to inverters, and, more particularly, to an inverter having circuit means for quickly shutting down and isolating the inverter from a critical load.
2. Description of the Prior Art
Inverters have been used in uninterruptible power systems (UPS) to convert a DC voltage to an AC voltage so as to provide a reliable power source to a critical bus, which bus in turn provides power to a critical load such as a computer. This critical load must have a voltage source which does not deviate in magnitude or frequency from very tight specifications in order to ensure its proper operation. Thus, quite often, a number or plurality of redundant uninterruptible power systems are used to supply the critical bus and load. If, however, there is a malfunction in the inverter of any UPS system, this inverter can adversely effect the overall voltage of the critical bus, thereby endangering the continued operation of computers which receive their power from that bus. In one failure mode, an inverter can be receiving an excess of reverse power from the critical bus. This could result in other redundant UPS systems supplying power to the failing inverter, thereby endangering the integrity of the critical bus.