| 摘要 |
PROBLEM TO BE SOLVED: To enable protection in accordance with the thermal breakage strength of an electric motor by reducing each element of a protective relay in the starting electric motor and using a digital protective relay, enable reduction of the cost and enlargement of an operation region by restricting overdesign in the starting electric motor, and reduce a workload of a plant operator. SOLUTION: This protective device of a gas turbine starting electric motor of a power generating plant uses a digital protective relay. An anti time-limit element 11 of the protective relay which is settled with respect to a starting current of the gas turbine starting electric motor and an elapsed time is used as an overcurrent trip element on starting the starting electric motor, and switched to and used as an overload warning element after completion of the start. The starting electric motor is protected by such switching from the overcurrent trip element to the overload warning element.
|
