Method of synchronous circuit opening of generator circuit breaker, and its control apparatus

A method of synchronous circuit opening of a generator circuit breaker for a generator main circuit comprising multiple generator systems in which a generator is connected to a transmission system via circuit breakers;

• wherein,
• at the time when occurrence of an electrical fault in the multiple generator systems is detected and any one of the generator systems is to be opened of its circuit synchronously using the circuit breaker installed for the generator system, if occurrence of an electrical fault is detected in other generator system than the above generator system to be opened of its circuit synchronously, a synchronous circuit breaker opening signal for the generator system to be opened of its circuit synchronously is kept as non-output for a specified length of time after the occurrence of an electrical fault is detected.

A control apparatus for synchronous circuit opening of a generator circuit breaker for a generator main circuit comprising multiple generator systems in which a generator is connected to a transmission system via circuit breakers;

• said multiple generator systems comprising a detecting apparatus for detecting occurrence of an electrical fault and a protection relay for shutting down the circuit breakers in case of an electrical fault;
• wherein,
• said control apparatus for synchronous circuit opening is provided with an interlock circuit which, at the time when a synchronous circuit opening command signal of a circuit breaker installed in a generator system is to be output, if an actuation signal of a protection relay installed in other generator system is output, suspends output of the synchronous circuit opening command signal for a specified length of time after the actuation signal is output.

A control apparatus for synchronous circuit opening of a generator circuit breaker for a generator main circuit comprising multiple generator systems in which a generator is connected to a transmission system via circuit breakers;

• said multiple generator systems comprising #1 and #2 current detectors which detect current of the generator systems and a protection relay which shuts down the circuit breakers installed in the generator systems if the difference of current or ratio of the difference of current detected by the #1 and #2 current detectors exceeds a preset value;
• wherein
• at the time when a circuit breaker installed in a generator system is to be opened synchronously, a synchronous circuit opening command signal of the circuit breaker is output by said control apparatus for synchronous circuit opening on condition that an actuation signal of the protection relay installed in other generator system is not being output.

A method of synchronous circuit opening of a generator circuit breaker for a generator main circuit in which multiple generators are connected to a transmission system via circuit breakers so that a circuit breaker can be closed or opened synchronously;

• wherein,
• at the time when a circuit breaker installed in a generator main circuit is to be opened synchronously, the amplitude of AC current waveform of the generator output is amplified before the circuit breaker is opened synchronously so that the AC current reaches current zero, and then the circuit breaker is opened synchronously.

A method of synchronous circuit opening of a generator circuit breaker for a generator main circuit comprising multiple generator system in which a generator is connected to a transmission system via circuit breakers;

• wherein,
• at the time when any one of the multiple generator systems is to be opened of its circuit synchronously, if occurrence of an electrical fault in other generator system than the above generator system to be opened of its circuit synchronously is detected, the circuit breaker installed in the generator system to be opened of its circuit synchronously is opened synchronously with priority, and the amplitude of AC current waveform of the generator output of the generator system to be opened of its circuit reaches current zero, and then the circuit breaker is opened synchronously.

A control apparatus for synchronous circuit opening of a generator circuit breaker for a generator main circuit comprising multiple generator systems in which a generator is connected to a transmission system via circuit breakers;

• wherein
• at the time when a circuit breaker of a generator system to be opened of its circuit synchronously out of the multiple generator systems is to be opened synchronously, the amplitude of AC current waveform of the generator output is amplified by said control apparatus for synchronous circuit opening before the circuit breaker is opened synchronously so that the AC current reaches current zero, and then the circuit breaker is opened synchronously.