JPS6444502A - Duplex system control device for water supply turbine - Google Patents

Abstract

PURPOSE:To attain smooth switching between two devices without using a communication means by continuously inputting the output of a proportional integrator for outputting a control signal for controlling a process operation terminal to be a controlled system alternately to the two devices by a hard wired means. CONSTITUTION:The same water supply commands 15a, 15b are inputted to digital controllers 4, 4' in water supply turbine control devices EHGs 6, 6' and the same operation is executed. Thereby, valve command signals 11, 11' to be output signals may be basically the same outputs, and when operation is continued for a long period, errors may be integrated and a large sudden change signal may be outputted at a switching moment between the control devices EHGs 6, 6'. Therefore, an I element of a proportional integrating computing element 10' e.g. in a waiting mode at present is initialized by a valve command signal 30a being controlled at present to prevent the generation of disturbance at the time of switching the devices.