Computerized control system for an electrochemical plant.

摘要

A power-demand control system for a plant facility having a plurality of electrical loads some of which are sheddable and some of which are selectively adjustable by electrical tapping control, uses all line control to bring about an ideal power consumption rate before the end of a demand period. A demand error signal is modified so as to project the demand toward a definite point on the ideal rate curve, then to follow the ideal rate toward the target. Correction at a chosen point in time takes into account a possible duration from ideal rate consumption by either choosing the ideal rate short of the target or by pointing exactly to the target. All lines are individually controlled by tap changing with variable deadband and hysteresis, and tap moves are estimated on the basis of individual wattage and amperage changes in a previous control cycle. The minimum between "necessary tap moves" and the "tap-moves possible withn an upper and a lower limit in the cell line amperage" is used for control. The system allows safe settings by the operator and establishes pass words to communicate with the computer system when protected steps are to be dealt with, by the engineer, for instance.