JPS5771020A - Constant water level controller - Google Patents

Abstract

PURPOSE:To realize smooth transition to constant water level controlling operation by determining a target water level which corresponds to inflow, by finding an operation water-level interval on the basis of the best frequency of gate operation, and by approximating discharge to the inflow. CONSTITUTION:The output of a water gauge is averaged by a water-level smoothing circuit 3, whose output is inputted as a current water level to discharge and inflow calculating circuits 4 and 5 and a gate operation water-level interval calculating circuit 9. Discharge calculated by the circuit 4 on the basis of the current water level and output information on the extent of gate opening is sent to the circuit 5, a gate operation frequency selecting circuit 7 and a discharge-limit-quantity calculating circuit 8. Inflow calculated by the circuit 5 is sent to a target water-level calculating circuit 6 and the circuit 7. In the circuit 6, target discharge and a control water-level interval are stored as data, and on the basis of an upper limit target set water level preset with a switch 6', the target water level is calculated and sent to a gate operation water-level interval calculating circuit 9. The circuits 8 and 7 calculates a frequency of gate operation until the inflow and discharge become equal to each other, and a water-level interval from the circuit 9 is passed through an opening-extent calculating circuit 10 to output an operation command from an output circuit 11 to gate.