AC motor controller

• US 20070096681A1
• Filed: 10/10/2006
• Published: 05/03/2007
• Est. Priority Date: 10/17/2005
• Status: Active Grant

• Current Assignee: Siemens Industry Incorporated (Siemens AG)
• Original Assignee: Siemens Industry Incorporated (Siemens AG)
• Inventors: Fan, Chun, Terricciano, Paul, Bilac, Mario
• Granted Patent: US 7,791,307 B2
• Time in Patent Office: Days
• US Class Current: 318/729
• CPC Class Codes: H02P 1/26 for starting an individual polyphase induction motor
• CPC Class Codes: H02P 23/0077 Characterised by the use of a particular software algorithm

Abstract

A system, method, and device for monitoring an AC induction motor are disclosed. The exemplary system provides the architecture of an intelligent motor controller. On one hand, the controller has self-commission and adaptive tuning capability and can provide smooth start and stop for motor driven systems. On the other hand, the controller can provide fault detection, power metering, and history data logging, to ensure motor operates under optimal conditions. The exemplary system may have one or more sensors for monitoring characteristics of the AC induction motor and producing one or more inputs from the characteristics.

Claims

1. A method for monitoring an AC induction motor, comprising:

monitoring one or more characteristics of the AC induction motor;

producing one or more inputs from the characteristics;

supplying the one or more inputs to a motor controller;

using fuzzy logic to determine one or more outputs of the controller to the AC induction motor; and

regulating the AC induction motor based on the one or more outputs of the controller.

2. The method of claim 1, wherein the one or more outputs are firing angles of a control rectifier of the AC induction motor.

3. The method of claim 1, wherein the one or more characteristics monitored are the line voltage on each of three phases.

4. The method of claim 1, wherein the one or more outputs is a power factor of the AC induction motor.

5. The method of claim 1, wherein the one or more outputs regulate current drawn by the AC induction motor.

6. The method of claim 1, wherein the one or more outputs set current limits drawn by the AC induction motor.

7. The method of claim 1, wherein the one or more characteristics monitored are terminal voltages on each of three phases.

8. The method of claim 1, wherein the one or more characteristics monitored are currents of each stator of the AC induction motor.

9. The method of claim 1, wherein using fuzzy logic to determine output of the controller reduces the voltage dip in a power grid supplying power to the AC induction motor.

10. The method of claim 1, wherein using the fuzzy logic to determine output of the controller reduces shock to mechanical systems of the AC induction motor.

11. A system for monitoring an AC induction motor, comprising:

one or more sensors for monitoring characteristics of the AC induction motor and producing one or more inputs from the characteristics;

a motor controller for receiving the one or more inputs and determining one or more outputs; and

a regulator for controlling the AC induction motor based on the one or more outputs of the fuzzy logic controller.

12. The system of claim 11, wherein the one or more outputs are firing angles of a control rectifier of the AC induction motor.

13. The system of claim 11, wherein the one or more characteristics monitored are the line voltage on each of three phases.

14. The system of claim 11, wherein the one or more outputs is a power factor of the AC induction motor.

15. The system of claim 11, wherein the one or more outputs regulate current drawn by the AC induction motor.

16. The system of claim 11, wherein the one or more outputs set current limits drawn by the AC induction motor.

17. The system of claim 11, wherein the one or more characteristics monitored are terminal voltages on each of three phases.

18. The system of claim 11, wherein the one or more characteristics monitored are currents of each stator of the AC induction motor.

19. The system of claim 11, wherein the fuzzy logic controller determines output to reduce voltage dip in a power grid supplying power to the AC induction motor.

20. A method for monitoring an AC induction motor, comprising:

monitoring one or more characteristics of the AC induction motor;

producing one or more inputs from the characteristics;

storing one or more inputs to produce a history of operation of the AC induction motor;

supplying the one or more inputs to a fault diagnosis controller; and

performing maintenance on the AC induction motor based on the one or more outputs of the controller.