Digital voltage regulator

• US 5,285,147 A
• Filed: 06/19/1991
• Issued: 02/08/1994
• Est. Priority Date: 11/02/1989
• Status: Expired due to Term

• Current Assignee: Sundstrand Corporation (Rtx Corporation)
• Original Assignee: Sundstrand Corporation (Rtx Corporation)
• Inventors: Rashid, Abdul
• Primary Examiner(s): Hickey, R. J.
• Application Number:
  US07/723,720
• Time in Patent Office: 965 Days
• Field of Search: 322/24, 322/25, 322/28, 322/29, 322/73, 322/20
• US Class Current: 322/28
• CPC Class Codes: H02P 2101/30 for aircraft
• CPC Class Codes: H02P 9/305 controlling voltage H02P9/302 takes precedence

Abstract

The problems of minimizing size and weight in aircraft and avoiding requirements for custom design are minimized in a digital voltage regulator circuit (120).

The circuit (120) includes a programmed processor circuit (124) having a memory circuit (138), and a drive circuit (132) operatively coupled with the processor circuit (124) for developing an exciter control signal.

This circuit (120) is manufactured using custom very large scale integration (VLSI) technology to reduce size, weight, life cycle costs and improve reliability.

Claims

1. In an electrical power generating system having a generator, sensing means for sensing generator system conditions, and means responsive to a control signal for varying generator output power, a voltage regulator comprising:

a digital control circuit comprising a single VLSI digital chip including an input circuit operatively connected to said sensing means and a processor having a memory circuit and an output circuit developing said control signal which comprises a pulse width modulated signal, said processor being responsive to system condition inputs for establishing a duty cycle of the control signal in accordance with an algorithm, which algorithm includes a control loop determining a difference between the sensed system conditions and desired system conditions to determine an error and a gain and compensation function responsive to such error for developing said duty cycle of the pulse width modulated control signal to maintain generator output power at a desired voltage level, and said memory circuit storing said algorithm and coefficients for said gain and compensation function.

2. The voltage regulator of claim 1 wherein said memory circuit includes a programmable memory circuit storing said algorithm and said coefficients.

3. The voltage regulator of claim 1 wherein said processor includes a sequencer having means for repeatedly implementing said algorithm.

4. The voltage regulator of claim 1 wherein said digital control circuit further comprises an interface circuit operatively connected to said processor for connection to an external processor and for receiving said coefficients to be stored in said memory circuit.

5. The voltage regulator of claim 1 wherein said input circuit comprises an interface circuit operatively connected to said processor for receiving signals representing said system condition inputs from said sensing means.

6. The voltage regulator of claim 5 wherein said interface circuit includes means for receiving a plurality of system condition inputs and means for storing data representing each such input in a select storage location in said memory circuit.

7. In an electrical power generating system having a main generator including an exciter excited responsive to a control signal for varying main generator output power and sensing means for sensing generator system conditions, a generator control unit comprising,

a digital VLSI voltage regulator circuit chip including an input circuit operatively connected to said sensing means, a programmed processor circuit having a memory circuit, said processor circuit implementing a program stored in said memory circuit, said program including a control loop responsive to the system conditions for establishing a command representing a level of said control signal required to maintain main generator output power at a desired voltage level, and a drive circuit operatively coupled with said processor for developing said exciter control signal, said drive circuit developing a pulse width modulated signal having a duty cycle in accordance with said command.

8. The generator control unit of claim 7 wherein said programmed processor circuit includes means for detecting existence of an abnormal system condition, and means operatively associated with said detecting means for modifying the command in response to the existence of an abnormal system condition.

9. The generator control unit of claim 7 wherein said program includes a gain and compensation function for stabilizing operation of said control loop and said memory circuit stores coefficients for said gain and compensation function.

10. The generator control unit of claim 9 wherein said voltage regulator circuit chip further comprises an interface circuit operatively connected to said processor for connection to an external processor and for receiving said coefficients to be stored in said memory circuit.

11. The generator control unit of claim 7 wherein said processor circuit includes a sequencer having means for repeatedly implementing said program.

12. The generator control unit of claim 7 wherein said input circuit includes means for receiving a plurality of system condition inputs and means for storing data representing each such input in a select storage location in said memory circuit.