Flow Control

Abstract

A pumping system for moving water of a swimming pool includes a water pump and a variable speed motor. The pumping system further includes means for determining a first motor speed of the motor, means for determining first and second performance values of the pumping system, and means for comparing the first and second performance values. The pumping system further includes means for determining an adjustment value based upon the comparison, means for determining a second motor speed based upon the adjustment value, and means for controlling the motor in response to the second motor speed. In one example, the pumping system includes means for determining a value indicative of a flow rate of water moved by the pump. In addition or alternatively, the pumping system includes a filter arrangement. A method of controlling the pumping system for moving the water of the swimming pool is also disclosed.

1 . A pumping system, comprising:
 a motor to be coupled to a pump; and   a controller in communication with the motor, the controller:
 determining a first motor speed of the motor; 
 determining a flow rate of a liquid based on a mathematical model of motor speeds versus flow rates for discrete power consumptions of the motor; 
 determining a difference value between the flow rate and a reference flow rate; and 
 driving the motor at a second motor speed based on the difference value. 
   
     
     
         2 . The pumping system of  claim 1 , wherein the controller determines a first power consumption of the motor. 
     
     
         3 . The pumping system of  claim 2 , wherein the controller determines the first power consumption of the motor based on at least one of a current or a voltage provided to the motor. 
     
     
         4 . The pumping system of  claim 2 , wherein the controller determines the first power consumption of the motor based on at least one of a power factor, a resistance, or a friction of the motor. 
     
     
         5 . The pumping system of  claim 2 , wherein the controller compares the first power consumption to a reference power consumption. 
     
     
         6 . The pumping system of  claim 1 , wherein the reference flow rate is based on at least one of a volume of the liquid, a rate of turnover of the liquid, or a time range that the pumping system is to operate. 
     
     
         7 . The pumping system of  claim 1 , further comprising a sensor in communication with the controller, the sensor measuring a shaft speed of the motor, wherein the controller determines the first motor speed based on the shaft speed. 
     
     
         8 . A method of controlling a pumping system including a motor, a pump coupled to the motor, and a controller in communication with the motor, the method comprising the steps of:
 determining a flow rate of a liquid based on at least one of a first motor speed of the motor or a power consumption of the motor; and   driving the motor at a second motor speed based on a difference value between a reference flow rate and the flow rate.   
     
     
         9 . The method of  claim 8 , further comprising the step of determining the first motor speed based on a shaft speed of the motor. 
     
     
         10 . The method of  claim 8 , further comprising the step of determining the reference flow rate based on at least one of a volume of the liquid, a rate of turnover of the liquid, or a time range that the pumping system is to operate. 
     
     
         11 . The method of  claim 8 , further comprising the step of determining the power consumption based on at least one of a current or a voltage provided to the motor. 
     
     
         12 . The method of  claim 8 , further comprising the step of determining the power consumption based on at least one of a power factor, a resistance, or a friction of the motor. 
     
     
         13 . A pumping system, comprising:
 a pump;   a motor coupled to the pump; and   a controller in communication with the motor, the controller
 determining a first motor speed; 
 obtaining a reference flow rate; 
 determining a reference power consumption based on the first motor speed and the reference flow rate; 
 determining a present power consumption; 
 calculating a difference value between the reference power consumption and the present power consumption; 
 using at least one of integral, proportional, and derivative control to generate a second motor speed based on the difference value; and 
 attempting to drive the motor at the second motor speed. 
   
     
     
         14 . The pumping system of  claim 13 , wherein a reference estimator determines the reference power consumption by at least one of calculation, look-up table, a graph, and a curve. 
     
     
         15 . The pumping system of  claim 14 , wherein the reference estimator uses curves of power versus speed for discrete flow rates to determine the reference power consumption. 
     
     
         16 . The pumping system of  claim 13 , wherein the reference flow rate is calculated based on at least one of a volume of at least one aquatic application with which the pumping system is used, a number of turnovers desired per day, and a time range that the pumping system is permitted to operate.