| 摘要 |
<p>A demand limiting system is provided for a large electrical energy customer with at least one modulating load. A master control unit continually compares the actual power usage to the desired rate of power usage. When the desired power consumption rate is exceeded by a first amount, the master provides a hold signal to an associated slave control unit, which prevents further loading of the modulating load. When the desired rate of power consumption is exceeded by a second amount, the master provides a reduce signal to the slave unit, which begins to reduce the load. While the hold signal is calling for a reduced load, only a fraction of the time is utilized to reduce the load, and the remainder of the time the modulating load is in the hold condition, allowing the system to stabilize and prevent hunting. The reduce signal also regulates load shedding equipment, to disconnect non-critical loads. A safety and alarm circuit provides various audible indications and/or shut-down operations responsive to detection of various fault conditions.</p> |
