Distributed power supply for high frequency PWM motor controller with IGBT switching transistors

• US 5,754,732 A
• Filed: 06/07/1995
• Issued: 05/19/1998
• Est. Priority Date: 06/07/1995
• Status: Expired due to Fees

• Current Assignee: Kollmorgen Corporation (Regal Rexnord Corp.)
• Original Assignee: Kollmorgen Corporation (Regal Rexnord Corp.)
• Inventors: Vlahu, Saso P.
• Primary Examiner(s): Cabeca, John W.
• Application Number:
  US08/472,812
• Time in Patent Office: 1,077 Days
• Field of Search: 318/811, 318/807, 318/809, 318/810, 318/800, 318/801, 318/803, 318/254, 318/138, 318/439, 388/811, 388/829, 388/819, 363/41, 363/40, 363/98, 323/265, 323/234, 323/271
• US Class Current: 388/811
• CPC Class Codes: H02P 6/08 Arrangements for controlling the speed or torque of a single motor H02P6/10, H02P6/28 take precedence
• CPC Class Codes: H03K 17/567 Circuits characterised by the use of more than one type of semiconductor device, e.g. BIMOS, composite devices such as IGBT

Abstract

A distributed power supply for a motor controller including electronic control circuits for controlling IGBT power transistor stages. The power supplies for the power transistors and gate drivers therefor are isolated from the power supplies for the electronic control circuits. Each of the gate drivers for the IGBT power transistor is supplied through a separate floating supply. Power supplies for the digital components and the analog components have separate ground return paths and are tied together at the supplies.

Claims

1. A power supply for a brushless motor controller for a motor having at least one winding, said controller being of the type including an digital electronic section to determine the amplitude, phase and frequency of the motor excitation current, a high frequency PWM electronic analog section for providing one or more pulse trains with pulse widths corresponding to sinusoidal current excitation for said motor, power transistors for controlling energization of said at least one winding in on/off fashion, and a separate gate drive responsive to one of said pulse trains for each of said power transistors to control the conductive state, wherein the gate drives and power transistors are isolated from said digital and analog electronic sections by pulse transformers, the improvement comprising:

a main power supply connected to supply current to said power transistors for energizing said at least one motor winding according to the pulse widths determined by said PWM electronic analog section;

a separate floating power supply for each of said gate drives, said separate floating power supplies being coupled to the power source through a first transformer;

a power supply for said PWM analog components coupled to the source via a second transformer separate from said first transformer;

wherein said isolation between said analog components and said gate drive components is maintained in the respective power supplies.

2. A power supply according to claim 1 wherein each of said floating power supplies is supplied from a high frequency oscillator source.

3. A power supply according to claim 1 further including a power supply for said digital electronic section and wherein said supply for said digital electronic section and said supply for said PWM analog components connect to the power source through separate transformers.

4. A power supply according to claim 3 wherein said digital section and said analog components return through separate ground return paths tied together at the supplies.

5. A controller for a brushless motor with at least one motor winding comprising

a digital electronic section for determining the amplitude, phase and frequency of the motor excitation current;

an electronic analog pulse width modulation section coupled to said digital electronic section for providing one or more pulse trains with pulse widths corresponding to sinusoidal current excitation for said motor, said pulse trains having a pulse rate greater than 6 KHz;

power transistors for controlling motor winding energization of said at least one winding in an on/off fashion;

separate gate drives each responsive to one of said pulse trains and operative to control the conductive state of said power transistors, said gate drives being isolated from said digital and analog sections by pulse transformers;

a main power supply connected to supply current to said power transistors for energizing said at least one motor winding according to pulse widths determined by said pulse width modulation section; and

a separate floating power supply for each of said gate drives, said floating power supplies being isolated from other power supplies for the controller.

6. The controller according to claim 5 further including a PWM power supply for said pulse width modulation section, said floating power supplies and said PWM power supply being coupled to the source via separate transformers.

7. The controller according to claim 6 further including a power supply for said digital electronic section and wherein said supply for said digital electronic section and said PWM power supply connect to the source through separate transformers.