ABB RET670 1MRK004816-AC transformer protection relay

ABB RET670 1MRK004816 - AC Transformer Protection Relay is a product specially designed for transformer protection, with the following features and application scenarios:

Features

Differential protection: As the main protection of the transformer, it can effectively detect faults such as phase-to-phase short circuit and turn-to-turn short circuit in the transformer internal winding. By comparing the magnitude and phase of the current on each side of the transformer, when the unbalanced current exceeds the set value, it quickly acts to cut off the fault to prevent the fault from expanding and causing serious damage to the transformer.

Overcurrent protection: Including high-set instantaneous phase overcurrent and ground overcurrent protection, directional or non-directional delayed phase overcurrent and ground overcurrent protection. It can protect the transformer from damage due to overcurrent when there is an external short circuit fault. At the same time, it can selectively act according to the type and location of the fault, cut off the fault line, and ensure the normal operation of the non-fault part.

Thermal overload protection: Simulates the heating process of the transformer winding, calculates the heat accumulation of the transformer according to the current magnitude and duration, and when the set overload threshold is reached, an alarm signal is issued or corresponding protection actions are taken to prevent the transformer from shortening its service life or failure due to long-term overload operation.

Undervoltage and overvoltage protection: monitors the operating voltage of the transformer. When the voltage is lower or higher than the set threshold, the relay will operate to prevent the transformer from operating under abnormal voltage, avoiding insulation damage due to excessive voltage, or affecting the output power and operating stability of the transformer due to low voltage.

Fault recording and positioning function: can record the changes in electrical quantities before and after the fault occurs, such as the waveform and value of current and voltage, which is helpful for post-fault analysis, accurately determine the type, location and cause of the fault, provide detailed fault information for maintenance personnel, shorten the troubleshooting time, and improve the reliability and maintainability of the power system.