Patent ID: 11870235
Assignee: LS ELECTRIC CO., LTD.
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H  G | IPC G  H

Claim 7:
8. A method for preventing malfunction of a self power relay, the method comprising:
converting, by a self power generator of the self power relay, a system power as a source power to a driving power having a preset driving power level to generate the driving power of the self power relay;
measuring, by a relay unit of the self power relay, a power amount of the system power in real time while operating using the driving power;
preventing, by the relay unit, the system power from being transmitted to a load in an event of failure of the system power;
monitoring, by the relay unit, change in the source power for the self power generator in real time; and
stopping, by the relay unit, an operation of the self power generator and a relaying operation of the self power relay when abnormality occurs in the source power,
wherein stopping the operation of the self power generator further comprises:
upon determination based on a plurality of predefined abnormality occurrence conditions that abnormality occurs in three phases system currents used as a source power of the self power generator, generating, by the relay unit, a fail signal to stop the relaying operation thereof and the operation of the self power generator,
after the relaying operation stops due to the fail signal, sampling, by the relay unit, the three phases system currents under a sampling condition changed due to the stop of the relaying operation,
calculating, by the relay unit, differences between sampling values of the three phases system currents as sampled under the changed sampling condition and monitor change in each of the three phases system currents in real time, based on the calculated differences, and
when the plurality of predefined abnormality occurrence conditions are not met, normally activating, by the relay unit, the relaying operation thereof and the operation of the self power generator operation.