| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a pump flow rate estimating system and a pump flow rate estimating method, for estimating a flow rate of a variable speed pump driven by variable voltage and a variable frequency power source controlled by delivery pressure constant control or estimated end pressure constant control, by an electric current and a speed of a driving electric motor and net generation pressure of the pump. Ž<P>SOLUTION: This invention measures a primary current of an electric motor driven by the variable voltage and the variable frequency power source, determines a secondary current of the electric motor by vectorially subtracting a preset exciting current from the measured primary current, estimates torque of the electric motor by multiplying an electric motor torque factor, and further arithmetically operates output of the electric motor by multiplying this estimated torque by an electric motor speed. A flow rate of the pump is arithmetically operated and estimated with pump efficiency as a known value, by measuring pump pressure, by applying the principle that the arithmetically operated electric motor output is equal to shaft power of the pump. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
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