Method and drive system for operating a synchronous motor

• US 7,492,118 B2
• Filed: 12/12/2006
• Issued: 02/17/2009
• Est. Priority Date: 11/07/2006
• Status: Expired due to Fees

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: Klaus, Michael, Burgstahler, Ralph
• Primary Examiner(s): Benson; Walter
• Assistant Examiner(s): Paul; Antony M
• Application Number:
  US11/637,458
• Publication Number:
  US 20080106230A1
• Time in Patent Office: 798 Days
• Field of Search: 318/721, 702/151
• US Class Current: 318/721
• CPC Class Codes: H02P 23/18 Controlling the angular speed together with angular position or phase
• CPC Class Codes: H02P 25/024 controlled by supply frequency

Abstract

In one aspect a method for operating a synchronous motor is provided. The method includes the following:

• Determining an electrical angle of rotation on the basis of a speed, with the synchronous motor being controlled according to the electrical angle of rotation,
• Determining a position of a rotor of the synchronous motor on the basis of the electrical angle or rotation and
• Determining the speed on the basis of the position of the rotor.

In an other aspect a drive system and a machine are provided. The machine has a plurality of synchronous motors with stator windings used to generate electrical poles. The drive system operates the synchronous motors synchronously.

Claims

1. A method for operating a first synchronous motor having stator windings used to generate electrical poles and having a first rotor, comprising:

providing a driving facility, having a first unit that determines an electrical rotation angle based upon a revolution speed of the first rotor, the electrical angle of rotation dependent upon the number of electrical poles, and a converter unit that controls the first synchronous motor according to the electrical rotation angle;

a computing apparatus separated from the driving facility, wherein an output value for a speed is transmitted from the computing apparatus to the driving facility, and wherein the computing unit has a closed-loop control unit that determines the revolution speed based upon the portion of the first rotor;

determining an electrical angle of rotation based upon a revolution speed of the first rotor, the electrical angle of rotation dependent upon the number of electrical poles;

controlling the first synchronous motor based upon the electrical angle of rotation;

determining a position of the first rotor based upon the electrical angle of rotation;

determining the revolution speed based upon the position of the first rotor;

providing a further synchronous motor having a further rotor operated by a position sensor that determines the position of the further rotor, and wherein the first synchronous motor is operated by the determined electrical rotation angle to determine the position of the first rotor, wherein the position data of the rotors are used for synchronizing the synchronous motors.

2. A drive system for operating a synchronous motor having stator windings to enforce electrical poles and having a rotor comprising:

a driving facility, having a first unit that determines an electrical rotation angle based upon a revolution speed of the rotor, the electrical angle of rotation dependent upon the number of electrical poles, and a converter unit that controls the synchronous motor according to the electrical rotation angle;

a second unit that determines a position of the rotor based upon the electrical angle of rotation; and

a computing apparatus separated from the driving facility, wherein an output value for a speed is transmitted from the computing apparatus to the driving facility, and wherein the computing unit has a closed-loop control unit that determines the revolution speed based upon the position of the rotor; and

a further synchronous motor having a further rotor operated by using a position sensor to determine the position of the further rotor and the synchronous motor without a position sensor, operated by using the determined electrical rotation angle to determine the position of the rotor.

3. The drive system as claimed in claim 2, further comprises a driving unit, wherein the converter unit and the first unit are integrated in the driving unit.

4. The drive system as claimed in claim 3, wherein the driving unit is physically connected to the synchronous motor and to a computing apparatus.

5. The drive system as claimed in claim 2, wherein the closed-loop control unit is integrated in a computing apparatus.

6. The drive system as claimed in claim 5, wherein the second unit is integrated in the computing apparatus.

7. The drive system as claimed in claim 3, wherein the second unit is integrated in the driving unit.

8. The drive system as claimed in claim 2, synchronized by using the positions of both rotors.