Local maintenance controller for gas turbine power plants having a primary control system

• US 3,975,902 A
• Filed: 06/04/1974
• Issued: 08/24/1976
• Est. Priority Date: 06/04/1974
• Status: Expired due to Term

• Current Assignee: Westinghouse Electric Corporation (Paramount Global (f/k/a ViacomCBS Inc.))
• Original Assignee: Westinghouse Electric Corporation (Paramount Global (f/k/a ViacomCBS Inc.))
• Inventors: Smith, Jack R., Reuther, John F., Yannone, Robert A., Shields, James J., Heiser, Richard S., Burrows, Leonard H., Hertz, Richard J., Pesavento, Joseph A.
• Primary Examiner(s): Gordon, Clarence R.
• Application Number:
  US05/476,182
• Time in Patent Office: 812 Days
• Field of Search: 60/39.28 R, 60/39.25, 415/10, 415/15, 415/17
• US Class Current: 60/39.25
• CPC Class Codes: F02C 9/00 Controlling gas-turbine plants; Controlling fuel supply in air- breathing jet-propulsion plants controlling air intakes F02C7/057; controlling turbines F01D; controlling compressors F04D27/00; controlling in general G05
• CPC Class Codes: G05B 7/02 electric
• CPC Class Codes: G05B 7/04 fluidic

Abstract

A local maintenance controller permits continued power generation during maintenance or failure of a primary gas turbine control system by manually for maintenance purposes or automatically for failure purposes assuming turbine control to thereby insure continued operation. The local maintenance controller set forth is particularly suitable for use in conjunction with a computer implemented gas turbine control system.

Transfer between the local maintenance controller and the primary control system is effected in a bumpless manner so that load swings are absent. However, if the turbine was operating at system reserve at the time of transfer, the local maintenance controller reduces the load to peak value until primary control is resumed. Operation at any other load at the time of transfer is maintained by the controller. Transfer back to primary control is also effected in a bumpless manner.

Pushbuttons provided on the controller and associated circuitry permit an operator to change loads as necessary within the limits of a peak performance curve. In addition, the turbine can be started, synchronized and loaded as necessary by the operator.

Claims

1. For a gas turbine power plant having a primary control system which develops a control signal output to control fuel flow to the gas turbine, backup control apparatus comprising:

a. input means for receiving information from the plant;

b. speed control means connected to said input means for developing an error speed signal;

c. temperature control means connected to said input means for developing an error temperature signal;

d. low selection means connected to said speed control and said temperature control means for developing a backup control signal output which is proportionally related to the lower of the two error signals received;

e. tracking means for monitoring, comparing and adjusting the backup control signal output with respect to the primary control signal output, connected between said input means and said low selection means;

f. speed/load reference generating means for developing a speed reference adjustment as a function of the backup control signal output connected between said tracking means and said speed control means;

g. fuel valve monitoring means for monitoring, comparing and transmitting the fuel valve position demand signals developed by the primary control system connected between and to said tracking means and said low selection means;

h. output means for receiving all information developed by said backup control apparatus connected to said low selector means and said fuel valve monitoring means;

i. transfer means connected to said output means and the output of the primary control system for switching the backup control apparatus outputs to the plant when required or passing the outputs of the primary control system to the plant when necessary;

j. transfer initiating means connected to said transfer means, said tracking means, said reference generating means and said fuel valve monitoring means for initiating action of said connected means in contemplation of transfer from the primary control system to said backup control apparatus; and

k. means for interfacing said backup control apparatus and the primary control system.

2. The power plant according to claim 1 wherein said backup control apparatus additionally comprises means for positioning and controlling the inlet guide vanes of the turbine, said means for positioning being connected between and to said input means, said output means and said transfer initiating means.

3. Control system apparatus for a gas turbine power plant, said control apparatus comprising:

a. input means for receiving information from the plant including signals representative of turbine speed and temperature;

b. digital computer implemented means for generating a first speed reference signal;

c. circuit means for generating a second speed reference signal;

d. speed control means, operably coupled to said input means and to receive said first and second speed reference signals, for developing a speed error signal and for generating a fuel control signal as a function thereof;

e. means for generating a temperature reference signal;

f. temperature control means, operably coupled to said input means and to receive said temperature reference signal, for developing a temperature error signal and for generating a fuel control signal as a function thereof;

g. turbine fuel delivery means connected to said speed and temperature control means, for developing a fuel valve position demand signal as a function of a fuel control signal delivered thereto;

h. selection means, connected between said speed and temperature control means and said turbine fuel delivery means, for selecting one of said fuel control signals for use by said turbine fuel delivery means in accordance with a predetermined criteria; and

i. switching means for causing generation of said speed dependent fuel control signal as a function of said second speed reference signal whenever said digital computer implemented means fails to generate said first speed reference signal.

4. The control system apparatus according to claim 3 wherein said speed control means includes first circuit means responsive to said first speed reference signal and independent second circuit means responsive to said second speed reference signal.

5. The control system apparatus according to claim 3 further comprising:

a. digital computer implemented means for generating a first temperature reference signal;

b. circuit means for generating a second temperature reference signal; and

wherein said switching means is adapted, when operable, to cause generation of said temperature dependent fuel control signal as a function of said second temperature reference signal whenever said digital computer implemented means fails to generate said first temperature reference signal.