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US 8,774,972 B2Granted
Intelligent pump system
AssigneeFlowserve Management Company
InventorsDennis M. Rusnak, Jason Ballard, Roger S. Turley
Life of this patent
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Abstract
The present invention is a controller specifically for pumps, making the benefits of variable frequency drive (VFD) technology more accessible to pump users. The present invention incorporates pump-specific system optimization software, an industrial grade drive, and a menu-driven user interface, offering protection, reliability, and ease of use not possible with other variable frequency drives.
Claims37
A method of controlling operation of a centrifugal pump in a fluid pumping system having a variable frequency drive (VFD) powering an alternating current (AC) motor which turns said centrifugal pump, said method comprising:
- internally monitoring automatically output current and voltage of the VFD to the AC motor without the need for an external sensor;
- calculating automatically output power based on monitored values of said output current and voltage and not on torque or speed of the AC motor;
- checking automatically whether said calculated output power is above a predetermined high power limit for a desired setpoint;
- checking automatically whether said calculated output power is below a predetermined low power limit for said desired setpoint,
- wherein said high and low power limits vary depending upon pump operating speed;
- receiving feedback from an external process sensor,
- wherein said feedback is indicative of said desired setpoint;
- and initiating automatically a first predetermined response action if said calculated output power is either above said predetermined high power limit or below said predetermined low power limit;
- wherein said high power limit is set to lowest of either power at the end of a performance curve of the pump, maximum rated motor power, or power rating of magnetic coupling of a magnetic drive pump or a canned motor pump, and wherein said low power limit is set for the highest of the performance curve of the pump or power required at minimum continuous recommended flow;
- using a high power level delay which is a time period that the output power must exceed the high power limit before said predetermined response action is initiated;
- monitoring an externally provided analog sensor signal;
- and initiating automatically a second predetermined response action if in a signal threshold level mode said analog sensor signal crosses one or both preset levels in the same direction,
- wherein each of said preset levels can initiate a separate response, or if in boundary mode, said analog sensor signal rising above a preset maximum value or drops below a preset minimum value, and in both modes, if after expiration of a time delay said analog sensor signal is still above one or both said preset levels if in a signal threshold level mode, or above or below said present maximum and minimum present values, respectively, if in boundary mode.
10 more elements
A method of controlling operation of a centrifugal pump in a fluid pumping system having a variable frequency drive (VFD) powering an alternating current (AC) motor which turns said centrifugal pump, said method comprising:
- internally monitoring automatically output current and voltage of the VFD to the AC motor without the need for an external sensor;
- calculating automatically output power based on monitored values of said output current and voltage and not on torque or speed of the AC motor;
- checking automatically whether said calculated output power is above a predetermined high power limit for a desired setpoint;
- checking automatically whether said calculated output power is below a predetermined low power limit for said desired setpoint, wherein said high and low power limits are fixed values;
- receiving feedback from an external process sensor, wherein said feedback is indicative of said desired setpoint;
- initiating automatically a first predetermined response action if said calculated output power is either above said predetermined high power limit or below said predetermined low power limit;
- wherein said high power limit is set to lowest of either power at the end of a performance curve of the pump, maximum rated motor power, or power rating of magnetic coupling of a magnetic drive pump or a canned motor pump, and wherein said low power limit is set for the highest of the performance curve of the pump or power required at minimum continuous recommended flow;
- using a high power level delay which is a time period that the output power must exceed the high power limit before said predetermined response action is initiated;
- monitoring an externally provided analog sensor signal;
- and initiating automatically a second predetermined response action if in a signal threshold level mode said analog sensor signal crosses one or both preset levels in the same direction,
- wherein each of said preset levels can initiate a separate response, or if in boundary mode, said analog sensor signal rising above a preset maximum value or drops below a preset minimum value, and in both modes, if after expiration of a time delay said analog sensor signal is still above one or both said preset levels if in a signal threshold level mode, or above or below said present maximum and minimum present values, respectively, if in boundary mode.
8 more elements
Dependencies are inferred from the claim text.