| 摘要 |
PROBLEM TO BE SOLVED: To succeed water supply at the time of failure by estimating at least two sets of pump torques corresponding to estimated no-discharge pump head of an operating pump, storing them, and adjusting the pump speed so as to coincide the pump torque with generated torque reference, with reference to the data. SOLUTION: When a control changeover switch 109 is set on the side indicated by a numeral 1, an output (h) of a pressure setter 101 is a pressure set value. A constant pressure control system of a variable speed control is thus formed. Abnormality of a pressure sensor is sensed based on the fact that the sensed pressure value is out of an allowable maximum value or always zero, or that the sensed pressure value is not interlocked with varying pump speed. At that time, an output of a PI controller 102 is forcibly set to be a value before sensing abnormality. The control changeover switch 109 is changed over to the torque controlling indicated by a numeral 2. A torque reference τs * is generated for performing constant pressure controlling with reference to at least too sets of data storing a torque value under the condition of a normally operated pressure sensor. |
