Dual generator system

• US 9,088,230 B2
• Filed: 06/01/2012
• Issued: 07/21/2015
• Est. Priority Date: 06/01/2012
• Status: Active Grant

• Current Assignee: Hamilton Sundstrand Corporation (Rtx Corporation)
• Original Assignee: Hamilton Sundstrand Corporation (Rtx Corporation)
• Inventors: Rozman, Gregory I., Gieras, Jacek F., Moss, Steven J.
• Primary Examiner(s): Fureman, Jared
• Assistant Examiner(s): Laguerre, Carlos
• Application Number:
  US13/486,829
• Publication Number:
  US 20130320763A1
• Time in Patent Office: 1,145 Days
• Field of Search: 307/43, 307/47, 307 64- 68, 307/84, 307/87, 322/46, 322/59, 322/86
• US Class Current: 1/1
• CPC Class Codes: H02P 9/02 Details of the control
• CPC Class Codes: H02P 9/30 using semiconductor devices

Abstract

A dual generator system includes a main generator and an auxiliary generator. The main generator generates at least a first phase main output and a second phase main output. The auxiliary generator generates at least a first phase auxiliary output and a second phase auxiliary output, wherein the first phase auxiliary output is combined with the first phase main output to generate a first phase main output. An auxiliary generator control unit (AGCU) monitors the first phase combined output and the second phase combined output and in response independently regulates the first phase auxiliary output and the second phase auxiliary output.

Claims

1. A dual generator system comprising:

a main generator that generates at least a first phase main output and a second phase main output;

a flux regulated permanent magnet generator (FRPMG) that generates at least a first phase auxiliary output and a second phase auxiliary output, wherein the first phase main output is combined with the first phase auxiliary output to generate a first phase combined output and the second phase main output is combined with the second phase auxiliary output to generate a second phase combined output, and wherein the FRPMG includes at least a first control winding and a second control winding and provides a first flux diverter control signal to the first control winding to regulate the first phase auxiliary output and provides a second flux diverter control signal to the second control winding to regulate the second phase auxiliary output; and

an auxiliary generator control unit (AGCU) comprising;

a first control loop that includes an outer control loop that compares the first phase combined output with a first phase reference value to generate a first flux diverter command signal and an inner loop that compares the first flux diverter command signal with the first flux diverter control signal and generates in response control signals to regulate the first flux diverter control signal to increase or decrease the first phase combined output; and

a second control loop that monitors the second phase combined output and in response regulates the second flux diverter control signal to increase or decrease the second phase combined output.

2. The dual generator system of claim 1, wherein the first phase combined output and the second phase combined output monitored by the AGCU is a voltage.

3. The dual generator system of claim 1, wherein the main generator and the auxiliary generator are connected to a common shaft for receiving a mechanical input.

4. The dual generator system of claim 1, wherein the main generator is a wound field synchronous machine that includes an exciter winding.

5. The dual generator system of claim 4, further including:

a main generator control unit (MGCU) that monitors an output of the main generator and in response provides excitation to the exciter winding to regulate the monitored output of the main generator.

6. A method of correcting imbalances between at least a first phase combined output and a second phase combined output of a dual generator system that includes a main generator that generates at least a first phase main output and a second phase main output and a flux regulated permanent magnet generator (FRPMG) that generates at least a first phase auxiliary output and a second phase auxiliary output, the FRPMG including a first control winding and a second control winding that are individually excited to independently regulate the first phase auxiliary output and the second phase auxiliary output, the method comprising:

monitoring voltage and/or current associated with each of the first phase combined output and the second phase combined output; and

independently regulating the first phase auxiliary output and the second phase auxiliary output of the auxiliary generator to correct imbalances between the first phase combined output and the second phase combined output;

wherein regulating the first phase auxiliary output of the FRPMG includes regulating a first flux diverter control signal provided to the first control winding based on the monitored voltage and/or current associated with the first phase combined output, and wherein regulating the second phase auxiliary output of the FRPMG includes regulating a second flux diverter control signal provided to the second control winding based on the monitored voltage and/or current associated with the second phase combined output; and

wherein regulating the first flux diverter control signal includes;

comparing the monitored voltage and/or current associated with the first phase combined output to a first phase reference value;

generating a flux diverter command signal based on the comparison of the monitored voltage and/or current associated with the first phase combined output with the first phase reference value;

monitoring the first flux diverter control signal provided to the first control winding;

comparing the first flux diverter command signal to the monitored first flux diverter control signal; and

regulating the first flux diverter control signal based on the comparison of the first flux diverter command signal to the monitored first flux diverter control signal.

7. An auxiliary generator control unit (AGCU) that controls the operation of a flux-regulated permanent magnet generator (FRPMG) employed in a dual generator system that also includes a main generator, wherein the FRPMG provides a first phase auxiliary output for combination with a first phase main generator output to generate a first phase combined output and a second phase auxiliary output for combination with a second phase main generator output to generate a second phase combined output, and wherein the AGCU generates a first flux diverter signal for provision to a first flux control winding of the FRPMG to regulate the first phase auxiliary output of the FRPMG, and generates a second flux diverter signal for provision to a second flux control winding of the FRPMG to independently regulated the second phase auxiliary output of the FRPMG, the AGCU comprising:

a first control loop circuit that includes;

a first comparator that compares the first combined output with a first reference value to calculate a first difference value;

a first proportional-integral (PI) controller that generates a first flux diverter command signal in response to the first difference value;

a second comparator that compares the first flux diverter command signal to the first flux diverter control signal provided to the first control winding to calculate a second difference value;

a second PI controller that generates a second reference signal in response to the second difference value;

a pulse-width modulator that generates pulse-width modulation (PWM) signals in response to the second reference signal; and

a gate drive circuit that generates gate drive signals based on the PWM signals for provision to a plurality of solid-state switching devices to selectively turn the solid-state switching devices On/Off to regulate the first flux diverter control signal provided to the first control winding; and

a second control loop circuit that monitors the second phase combined output, compares the second phase combined output with a second reference value to detect imbalances in the monitored second phase output indicative of an unbalanced load, and regulates the second phase auxiliary output to correct detected imbalances.