Application: It is mainly used for the protection, monitoring and control of electrical equipment and circuits in the power system, especially for transformer protection. It can be used as a tertiary busbar protection, etc. It can achieve fast and selective protection, monitoring and control of two-winding and three-winding transformers. Through the protection device, functions such as tripping when the pressure relief/gas protection operates can be realized.
Function Description: It has a variety of protection functions, including the voltage backup protection of the transformer, differential protection, etc. For differential protection, the second and fifth harmonic braking under the conditions of inrush current and overexcitation is considered. It also includes an adaptive stabilization function, which is used for the inrush current during the power system restoration and the CT saturation of the transformer during external faults. The distance protection area can operate independently, with directional (forward or reverse) or non-directional modes, and is suitable for the power system oscillation situations after heavy load disconnection or tripping of large power plants. In addition, there are functions such as overfrequency protection, overvoltage protection, undervoltage protection, and circuit breaker failure protection.

Data Sheet
General Information: The product model is RET670, version 1.2, the product ID is 1MRK002816-AC. It belongs to the category of transformer protection, and its global commercial name is RET670, version 1.2. The tariff number is 85363010. It is a non-customized product, with a minimum order quantity of 1 piece, and the sales unit is piece. It is in stock in the warehouses in Västerås, Sweden and Bangalore, India, and it is not within the scope of WEEE.
Technical Specifications: The rated voltage is up to 245kV, the rated frequency is 50/60Hz, the rated current is up to 5A, and it has 32 inputs and 32 outputs. It supports a variety of communication protocols, such as IEC 61850, Modbus, DNP 3.0, Profibus, IEC 60870-5-103. The programming logic allows users to write user logic for specific applications through a graphical tool.

In addition, in terms of functions, the RET670 has differential protection, ground fault protection, distance protection, overcurrent and thermal protection, and circuit breaker failure protection, etc. Among them, the differential protection is used for low-level internal faults, and the second and fifth harmonic braking is adopted to deal with the inrush current and overexcitation; the ground fault protection has low-impedance and high-impedance protection functions, which are used for winding ground faults; the distance protection serves as the backup protection for phase-to-phase and phase-to-ground faults; the overcurrent and thermal protection has configurable overcurrent and thermal overload protection with multiple time constants; the circuit breaker failure protection can ensure a quick response when the circuit breaker fails, causing the surrounding circuit breakers to trip.