| 摘要 |
PROBLEM TO BE SOLVED: To reduce the malfunction/tripping failure of a shear pin protective device for gas turbine generator by predicting the fracture of a shear pin. SOLUTION: The terminal voltage and current of a generator 42 are detected by means of a transformer PT and a current transformer CT, inputted to an A/D converter A/D, and converted into digital signals. The digital signals are supplied to an electrical output torque calculating section 11 and the section 11 calculates the electrical output torque of the generator 42. The electrical output torque calculated by means of the section 11, the electrical output torque calculated immediately before a failure occurs, and the constant of the generator 42, are supplied to a shaft torsional oscillation calculating section 12, and the section 12 calculates the shaft torsional oscillation of the generator 42 and supplies the calculated result to a detecting section 13. The section 13 sends a breaking command to a system-interconnection circuit breaker 47 when the detected value of the supplied shaft torsional oscillation becomes a fixed value or higher.
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