Process and device for feedback-controlling rotary machines

• US 20030057904A1
• Filed: 08/19/2002
• Published: 03/27/2003
• Est. Priority Date: 08/22/2001
• Status: Abandoned Application

• Current Assignee: Pumpenfabrik Ernst Vogel GmbH (ITT, Inc.)
• Original Assignee: Pumpenfabrik Ernst Vogel GmbH (ITT, Inc.)
• Inventors: Sacher, Ing. Manfred
• Application Number:
  US10/223,588
• Publication Number:
  US 20030057904A1
• Time in Patent Office: Days
• US Class Current: 318/268
• CPC Class Codes: F04D 27/004 by varying driving speed
• CPC Class Codes: F05D 2270/335 Output power or torque
• CPC Class Codes: H02P 27/06 using dc to ac converters or inverters H02P27/05 takes precedence
• CPC Class Codes: Y02B 30/70 Efficient control or regulation technologies, e.g. for control of refrigerant flow, motor or heating

Abstract

The invention relates to a process and device for feedback-controlling the speed of an electric motor (10) driving a rotary machine (6), in particular a pump or fan, according to the capacity requirement at the rotary machine, which is variable with time on the consumer side (4, 8) thereof, using a feedback controller (16) the output of which determines the speed of the electric motor (10). The process according to the invention is characterized in that the electrical power (P) actually taken up by the electric motor (10) is measured and in that a signal representing the electrical power measured is produced and supplied as input to the feedback controller (16), where it is converted into the desired output according to a predetermined or right then calculated characteristic curve (P_install(Q)).

Claims

1. A process for feedback-controlling the speed of an electric motor (10) driving a rotary machine (6), in particular a pump or fan, according to the capacity requirement at the rotary machine, which is variable with time on the consumer side (4, 8) thereof, using a feedback controller (16) the output of which determines the speed of the electric motor (10), characterized in that the electrical power (P) actually taken up by the electric motor (10) is measured and in that a signal representing the electrical power measured is produced and supplied as input to the feedback controller (16), where it is converted into the desired output according to a predetermined or right then calculated characteristic curve (P_install(Q)).

2. The process according to claim 1, characterized in that a frequency converter (12) is used for controlling the speed of the electric motor (10).

3. The process according to claim 2, characterized in that the electrical power is measured inside the frequency converter (12).

4. The process according to claim 2, characterized in that the electrical power is measured in between the frequency converter (12) and the electric motor (10).

5. A device for carrying out the process according to claim 1, having an electric motor (10) driving a rotary machine (6), control means (12) for the speed of the electric motor, and a feedback controller (16) the feedback-control output of which is connected to the control input of control means (12), characterized in that a power measurement instrument (14) is series connected ahead of the electric motor (10) for measuring the electrical power (P) taken up by the motor, the signal output of which instrument (14) is connected to the input of the feedback controller (16).

6. The device according to claim 5, characterized in that control means (12) is a frequency converter.

7. The device according to claim 6, characterized in that a power measurement instrument (14) is provided inside the frequency converter.

8. The device according to any of claims 5 to 7, characterized in that the feedback controller (16) is realized using a digital feedback-control instrument.

9. The device according to any of claims 5 to 8, characterized in that the rotary machine (6) has characteristic power curves of strictly monotonic course.