| 摘要 |
PURPOSE:To prevent erroneous function of a protective relay with charging current compensation by introducing the voltage of the relay to the counterpart end and comparing with the voltage thereat thereby detecting malfunction of a DC transformer. CONSTITUTION:Currents at the ends of DC current transformers 2A, 2B and voltages at the ends of DC transformers 3A, 3B are fed, along with the currents and voltages at the counterpart ends transmitted through transmitters 5A, 5B, to protective relays 4A, 4B where they are processed thus deciding fault within a section. Variation of voltage is compared between one and the counterpart ends and when they do not match for a predetermined time, a decision is made that the DC transformer 2A or 2B has malfunctioned and the relay 4A or 4B is locked in order to prevent malfunction while furthermore an alarm is delivered. This constitution prevents erroneous function. |
