Flow control
Embodiments of the invention provide a pumping system for at least one aquatic application. The pumping system includes a pump, a motor coupled to the pump, and a controller in communication with the motor. The controller determines a first motor speed, obtains a reference flow rate, determines a present flow rate, and determines a present power consumption. The controller calculates a difference value between the reference flow rate and the present flow rate, and uses at least one of integral, proportional, and derivative control to generate a second motor speed based on the difference value. The controller attempts to drive the motor at the second motor speed until reaching a steady state condition.
1. A pumping system for at least one aquatic application, the 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, the controller obtaining a reference flow rate, the controller determining a present flow rate, the controller accessing curves of speed versus flow rate for discrete power consumptions to determine the present flow rate, the controller determining a present power consumption, the controller calculating a difference value between the reference flow rate and the present flow rate, the controller using at least one of integral, proportional, and derivative control to generate a second motor speed based on the difference value, and the controller attempting to drive the motor at the second motor speed until reaching a steady state condition.
2. The pumping system of claim 1 , wherein the first motor speed is determined from a present shaft speed of a synchronous motor.
3. The pumping system of claim 1 , wherein the reference flow rate is calculated based on at least one of a volume of the at least one aquatic application, a number of turnovers desired per day, and a time range that the pumping system is permitted to operate.
4. The pumping system of claim 1 , wherein the present power consumption is based on at least one of current and voltage provided to the motor.
5. The pumping system of claim 1 , wherein the present power consumption is based on at least one of a power factor, resistance, and friction of the motor.
6. A pumping system for at least one aquatic application, the 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,
the controller obtaining a reference flow rate,
the controller determining a present power consumption,
the controller determining a present flow rate, wherein a flow estimator uses curves of speed versus flow rate for discrete power consumptions to determine the present flow rate,
the controller calculating a difference value between the reference flow rate and the present flow rate,
the controller using at least one of integral, proportional, and derivative control to generate a second motor speed based on the difference value, and
the controller attempting to drive the motor at the second motor speed until reaching a steady state condition.
7. The pumping system of claim 6 , wherein the first motor speed is determined from a present shaft speed of a synchronous motor.
8. The pumping system of claim 6 , wherein the reference flow rate is calculated based on at least one of a volume of the at least one aquatic application, a number of turnovers desired per day, and a time range that the pumping system is permitted to operate.
9. The pumping system of claim 6 , wherein the present power consumption is based on at least one of current and voltage provided to the motor.
10. The pumping system of claim 6 , wherein the present power consumption is based on at least one of a power factor, resistance, and friction of the motor.
11. A method of controlling a pumping system, the method comprising:
providing a motor coupled to a pump;
providing a controller in communication with the motor;
determining a first motor speed value;
determining a present power consumption value;
obtaining a reference flow rate value;
determining a present flow rate value using curves of speed versus flow rate for discrete power consumptions;
generating a difference value between the reference flow rate and the present flow rate; and
driving the motor at a second motor speed based on the difference value until reaching a steady state condition.
12. The method of claim 11 , wherein the first motor speed is determined directly from a sensor reading a present shaft speed.
13. The method of claim 11 , wherein the first motor speed is determined from a present shaft speed of a synchronous motor.
14. The method of claim 11 , wherein the reference flow rate is calculated based on at least one of a volume of the at least one aquatic application, a number of turnovers desired per day, and a time range that the pumping system is permitted to operate.
15. The method of claim 11 , wherein the present power consumption is based on at least one of current and voltage provided to the motor.
16. The method of claim 11 , wherein the present power consumption is based on at least one of a power factor, resistance, and friction of the motor.