ACCELERATION CONTROL CIRCUIT FOR A GAS TURBINE

• US 3,662,545 A
• Filed: 08/24/1970
• Issued: 05/16/1972
• Est. Priority Date: 08/24/1970
• Status: Expired due to Term

• Current Assignee: Richard K. Davis
• Original Assignee: Richard K. Davis
• Inventors: Davis, Richard K.
• Primary Examiner(s): Gordon, Clarence R.
• Application Number:
  US05/066,268
• Time in Patent Office: 631 Days
• Field of Search: 60/39.28
• US Class Current: 60/39.281
• CPC Class Codes: F02C 9/32 characterised by throttling of fuel F02C9/38 takes precedence

Abstract

An electrical control circuit for adjusting the fuel input to rotating machinery such as a gas turbine during acceleration, includes a positive speed feedback signal in opposition to a reference signal representing maximum allowable acceleration. A third input signal, applied to the input of the control circuit in equal opposition to the speed reference signal when the acceleration of the turbine is zero, prevents a time delay from occurring in control reaction to changes in speed of the turbine.

Claims

1. A circuit for limiting acceleration of rotating machinery by regulation of the fuel input, said circuit having applied thereto a feedback signal of one polarity proportional to the instantaneous speed of the machinery being controlled, and a reference signal proportional to the desired speed of the machinery, having a polarity opposing that of the speed feedback signal, said circuit comprising:

a. an amplifier;

b. connecting means including a capacitor in circuit with one of said feedback signal and said reference signal for supplying inputs to said amplifier whereby the total input current to said amplifier is proportional to the difference between the actual acceleration and the allowable acceleration; and

c. switching means connected to said amplifier for applying a signal to the input of said amplifier in opposition to the reference signal when the output of said amplifier is greater than said predetermined value whereby the combined value of the speed reference signal and the speed feedback signal, and the signal derived from said switching means is zero.

2. A circuit for limiting acceleration of rotating machinery by regulation of fuel input, said circuit having applied thereto a feedback signal of one polarity proportional to the speed of the machine being controlled, and a reference signal proportional to the desired speed of the machine having a polarity opposing that of the speed feedback signal, said circuit comprising:

a. means for differentiating the speed feedback signal;

b. means for algebraically summing said differentiated feedback signal and the speed reference signal;

c. means connected to said summing means for producing an output signal having a magnitude proportional to the sum of said differentiated feedback signal and said reference signal;

d. switching means connected to said output signal for applying an opposing signal to said summing means equal to said reference signal when said output signal has reached a predetermined magnitude whereby the sum of said differentiated feedback signal, said speed reference signal and said opposing signal is equal to zero; and

e. means connected to said output signal producing means for regulating fuel input to said rotating machine in proportion to said output signal, when said output signal has a value greater than said predetermined magnitude.

3. The invention claimed in claim 2 wherein the differentiating means comprises a capacitor and resistor circuit.

4. The invention claimed in claim 2 wherein the output signal means comprises an operational amplifier.

5. A circuit for limiting acceleration of rotating machinery by regulating fuel input, said circuit having applied thereto a feedback signal proportional to the speed of the machinery being controlled, and a reference signal proportional to the desired speed of the machinery:

a. a reference signal source;

b. a capacitor connected to said reference signal source for storing a quantity of electrical energy to achieve a predetermined voltage level;

c. means connected to said capacitor, said means having input connections adapted to receive the speed feedback signal, a signal proportional to said stored energy at said predetermined voltage level, said means producing an output signal in response to the application of said stored energy signal and said feedback signal;

d. switching means connected to said output signal producing means and said capacitor, responsive to a predetermined level of said output signal, for diverting the stored energy signal from said capacitor when said output signal exceeds said predetermined levels whereby the combined value of the stored energy signal and the speed feedback signal is equal to zero; and

e. a means connected to said output signal means for regulating fuel input to the rotating machinery in proportion to said varying output signal when said output signal has a value which is greater than said predetermined level.

6. The invention claimed in claim 5 wherein said output producing means comprises an operational amplifier having a normal input connection and an inverse input connection.

7. The invention claimed in claim 6 wherein said switching means is a transistor connected to said capacitor and said normal input connection of said operational amplifier.

8. The invention claimed in claim 6 wherein said speed feedback signal is applied to said inverse connection of said operational amplifier.