Method for maximizing power output in permanent field synchronous motors

• US 6,806,676 B2
• Filed: 11/25/2002
• Issued: 10/19/2004
• Est. Priority Date: 11/27/2001
• Status: Active Grant

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: Georg, Klaus, Papiernik, Wolfgang, Kuenzel, Stefan
• Primary Examiner(s): Duda, Rina
• Assistant Examiner(s): COLON SANTANA, EDUARDO
• Application Number:
  US10/303,404
• Publication Number:
  US 20040008004A1
• Time in Patent Office: 694 Days
• Field of Search: 318/700, 318/714, 318/715, 318/717, 318/721, 318/722, 318/654, 318/655, 318/85, 318/437, 318/438, 318/136, 318/729, 318/139, 318/798-811, 318/432, 318/434, 738/620.8, 323/205, 323/207
• US Class Current: 318/700
• CPC Class Codes: H02P 21/06 Rotor flux based control involving the use of rotor position or rotor speed sensors
• CPC Class Codes: H02P 25/08 Reluctance motors
• CPC Class Codes: H02P 6/08 Arrangements for controlling the speed or torque of a single motor H02P6/10, H02P6/28 take precedence

Abstract

A method of maximizing the power or torque output of a synchronous motor with reluctance effect is disclosed. Bases on torque and voltage set points, in the regulation of the synchronous motor, an optimal torque- and field producing current is generated. The method can further generate an optimal voltage which can maximize the power output of a synchronous motor since changes of inductances generated by the current itself can be accounted for.

Claims

1. A method for maximizing power output in a synchronous motor, said method comprising the steps of:

generating a torque-producing current within said synchronous motor being optimal with respect to torque and power generation;

deriving a field-generating current from said torque-producing current;

deriving an optimal torque-producing current from said torque-producing current and said field-generating current;

generating an optimal voltage corresponding to said optimal torque-producing current; and

using said optimal voltage to control the power output in said synchronous motor.

2. The method of claim 1, wherein said optimal torque and field producing current is derived through iterative feedback.

3. The method of claim 1, wherein said field-generating current is derived directly from the inductances of said synchronous motor.

4. The method of claim 1, further comprising:

calculating a torque set point;

calculating a voltage set point corresponding to said torque set point;

deriving an optimal field-generating current and a torque-producing current based on torque and voltage set points for regulating said synchronous motor.