ABB Electrical RET 316 Numerical Transformer Protection Unit

ABB Electrical RET 316 Numerical Transformer Protection Unit

Functional features

Comprehensive protection function:

Differential protection: detecting faults by comparing the difference between the currents on both sides of the transformer, it can quickly and sensitively identify the phase-to-phase and turn-to-turn short-circuit faults inside the transformer, and provide main protection for the transformer.

Overcurrent protection: including time-limited overcurrent protection and inverse time-limited overcurrent protection and other characteristics, according to different fault current size and duration to act accurately, effectively preventing the transformer from being damaged due to overload or external short-circuit.

Grounding protection: with zero sequence overcurrent protection and sensitive limiting grounding protection and other functions, can reliably detect single-phase grounding faults in the transformer neutral grounding system, to protect the safe operation of the power system.

Voltage protection: provide over-voltage protection, low-voltage protection and other functions, can prevent the transformer from being damaged due to abnormal voltage, and ensure the transformer to operate stably within the specified voltage range.

Non-electricity protection: it can be connected to light gas alarm contact, heavy gas action contact, oil temperature high action contact and pressure release action contact and other non-electric signals to achieve the monitoring and protection of the transformer's oil temperature, oil level, gas and other non-electric quantities, and send out alarm signals or trip commands in time when there are abnormalities, to protect the safety of the transformer.

Flexible configuration: according to the specific transformer parameters and protection requirements, users can use the Windows-based operating programme CAP2/316 to configure the parameters and functions of the RET 316 through a personal computer, select the required protection functions, and adjust the protection value to meet the protection requirements of different applications.

Advanced signal processing technology: Adopting all-digital signal processing, it can process and analyse the collected analogue signals such as current and voltage with high precision digitally, which effectively improves the accuracy and reliability of the protection, responds to all kinds of faults quickly, shortens the time of fault removal, and reduces the impact of faults on the transformer and the power system.

Event Record and Analysis Function: It can record various events in the process of transformer operation, such as protection action events, alarm events, switching quantity displacement events, etc., and time mark and store these events. Users can understand the operation status and fault condition of the transformer by checking the event record, which is convenient for fault analysis and accident memory.

Communication function: Equipped with serial communication port, it supports data communication with other devices, such as connecting with substation automation system, monitoring system, etc., to realise remote monitoring, data transmission and remote control, etc., which is convenient for the user to carry out centralized management and remote operation of transformer protection devices.

Technical Parameters

Rated voltage: usually applicable to medium voltage power system, the specific rated voltage value should be determined according to the actual application.

Rated current: it can be selected and configured according to different transformer capacity and load current to meet the effective protection of transformer.

Protection accuracy: the measurement of analogue quantities such as current and voltage and the protection action have high accuracy, and can accurately detect the tiny fault current and voltage changes to ensure the reliability and sensitivity of the protection.

Response time: it can respond quickly when a fault occurs, generally the action time of differential protection is at the millisecond level, which can quickly cut off the fault circuit and minimise the damage of the fault to the transformer.

Application fields

Power substation: widely used in substations of various voltage levels, comprehensive protection and monitoring of transformers in the station, to ensure the safe and stable operation of the substation, to ensure the reliable supply of electricity.

Industrial power distribution system: in the power distribution system of factories, mines, metallurgy, chemical industry and other industrial fields, it is used to protect important transformer equipment, prevent production interruption due to transformer failure, and improve the continuity and reliability of industrial production.

Commercial buildings and infrastructures: in the power supply and distribution systems of large commercial buildings and infrastructures such as shopping malls, office buildings, hospitals, airports, etc., the RET 316 can provide reliable protection for transformers, safeguard the normal power demand of these places, and ensure the safe operation of all kinds of electrical equipment.