ABB REF615 Feeder Protection and Control

ABB REF615 Feeder Protection and Control

REF615 Overview

Product positioning and family background: REF615 belongs to ABB Relion ®  The 615 series is an intelligent electronic device (IED) specifically designed for public substations and industrial power systems. This series is characterized by compact design and withdrawable units. The REF615 undertakes important tasks of protection, control, measurement, and monitoring, and is widely applicable to various distribution networks, including radial, ring, and mesh networks with or without distributed generation.

Version Evolution and Function Expansion: Continuously upgraded from version 1.0 to version 4.0, various new features and characteristics have been added, such as supporting more communication protocols, adding new standard configurations, and improving measurement and protection functions.

Hardware composition and interface configuration: It consists of a plug-in unit and a chassis. The plug-in unit includes various modules such as HMI, auxiliary power/BO module, BI/O module, etc. The combination and function of modules with different configurations are different. It has rich interfaces, including analog input/output interfaces, binary input/output interfaces, and multiple communication interfaces, which facilitate connection and data transmission with various devices.

Human machine interface and operation management: It has two types of human-machine interfaces: local HMI and web HMI. The local HMI integrates elements such as display, buttons, and LED indicator lights for device settings, monitoring, and control operations; Web HMI supports access through a web browser, providing more features such as programmable LED and event lists, system monitoring, parameter settings, etc. At the same time, the device is equipped with different user categories, each with different operational permissions, ensuring the safety of device operation.

Communication capability and network support: Supports multiple communication protocols, among which the IEC 61850 protocol has the most comprehensive functions, enabling high-speed data exchange, parameter setting, and fault record access between devices. Supports Ethernet communication, can be connected to the network through RJ-45 or fiber LC connectors, and has certain requirements for the RSTP protocol of external switches in redundant ring network topology to ensure stable network operation.

REF615 standard configuration

Overview of Configuration Types and Functions: Nine standard configurations (A-J) are provided, each optimized for specific power system application scenarios, covering from simple non directional overcurrent and ground fault protection to complex comprehensive configurations with multiple measurement and protection functions. These configurations vary in terms of protection functions, control functions, measurement functions, and applicable network types.

Detailed configuration explanation: Taking configuration A as an example, it is mainly used for cable and overhead line feeder protection in isolated and resonant grounded distribution networks, with multiple protection functions. The default I/O connection and interference recorder settings are clearly defined, and the functional diagram shows the connection relationship and signal flow direction between each functional module. Other configurations (B-J) are also applicable to different network scenarios, such as direct or resistance grounded distribution networks, asynchronous motor protection, etc., with detailed descriptions and differences in their respective functions, I/O connections, and functional diagrams.

Requirements for measuring transformers: In the power system, measuring the performance of transformers is crucial for the protection function of REF615. For non directional overcurrent protection, the selection of current transformers (CTs) should be cautious, as their accuracy level and accuracy limit factor can affect the protection performance. Accuracy levels such as 5P and 10P are suitable for this protection, with 5P having higher accuracy; The actual accuracy limit factor differs from the rated value, which is related to the CT burden. The selection of CT also needs to consider the magnitude of network fault current, protection objectives, and actual burden. At the same time, relevant formulas and examples for setting rated primary current and starting current are provided to ensure that CT can meet protection requirements under different fault conditions.

IED physical connection: The physical connection of REF615 includes two parts: input and output. The input section covers various types, such as phase current, residual current, phase voltage, residual voltage, sensor input, auxiliary power supply voltage input, and binary input. The connection terminals of each input vary under different configurations. The output section includes output contacts for tripping and control, output contacts for signal indication, and IRF (internal fault relay) contacts. These output contacts have different functions and connection methods, and are used to control and provide signal feedback to external devices.

Glossary: In order to facilitate the understanding of professional terms in the document, the manual provides a detailed terminology list with clear explanations of the relevant professional vocabulary, such as 615 series, ANSI, ASCII, BI, BO, etc., which helps readers accurately grasp the technical content in the document.

Technical specifications

Communication protocol support

Multi protocol adaptation: REF615 supports multiple communication protocols, including IEC 61850, IEC 60870-5-103, Modbus ®  And DNP3. Among them, the IEC 61850 communication protocol has comprehensive functions, supporting all monitoring and control functions, enabling access to parameter settings, interference records, and fault records, and interference records can be used for Ethernet based applications through the standard COMTRADE file format. The device can send and receive binary signals (horizontal communication) with a total transmission time of up to 3ms through this protocol, and also supports sending and receiving analog values, meeting the GOOSE performance requirements for distribution station tripping applications. At the same time, it can report events to five different clients.

Network connectivity capability: Equipped with Ethernet interface (RJ-45100Base TX or fiber LC connector, 100Base FX), it can be connected to Ethernet based communication systems. Optional serial interfaces (RS-232/RS-485) are also provided for serial communication. In a redundant ring network topology, although the devices themselves do not support link detection and RSTP protocol, enabling RSTP protocol on external switches can ensure the normal operation of the network, and this Ethernet ring network solution can connect up to thirty 615 series IEDs.

Hardware specifications

Structure and module composition: Composed of plug-in units and chassis, the plug-in units contain multiple functional modules. The HMI module has two display specifications: small (4 lines, 16 characters) and large (8 lines, 16 characters); X100 is an auxiliary power/BO module that provides power inputs with different voltage ranges and has multiple types of output contacts; X110, X120 and other input/output modules with different functions provide analog and binary input/output interfaces according to different configurations. For example, X120 has 3-phase current input and 1-phase residual current input in some configurations.

Input/output characteristics: In terms of analog input, the range of current input (such as phase current, residual current) and voltage input (phase voltage, residual voltage) varies under different configurations, and the rated values of some inputs can be used as basic setting parameters. The binary input threshold can be selected within the range of 18-176V DC by adjusting the relevant parameter settings. In terms of output, it has heavy-duty contacts (PO1-PO4) for tripping and control, as well as output contacts (SO1-SO4) for signal indication, which have different functions and connection methods.

Function characteristics

Protection function: It has rich protection functions and sets multiple protection mechanisms for different types of faults. Overcurrent protection includes three-phase non directional overcurrent protection (low, high, instantaneous stages) and three-phase directional overcurrent protection (low, high stages); Ground fault protection includes non directional ground fault protection, directional ground fault protection, and can also choose ground fault protection methods based on admittance, watt measurement, or harmonics; In addition, there are voltage protection (including overvoltage, undervoltage, residual overvoltage, etc.), frequency protection, thermal protection, circuit breaker fault protection, etc.

Control and monitoring functions: Control functions include circuit breaker control, isolation switch control, grounding switch control, etc., which can achieve remote or local operation of power equipment. The monitoring function involves monitoring the status of circuit breakers, tripping circuits, current circuits, fuse faults, etc. By monitoring the real-time operation status of equipment, it ensures the safe and stable operation of the power system. At the same time, it also has measurement function, which can measure parameters such as three-phase current, voltage, power, energy, frequency, etc.

Event recording and auditing: With event recording function, it can store 2048 system events into non-volatile audit trails, and 1024 process events are stored in non-volatile event lists, all following the FIFO principle. Audit tracking records system activities, including configuration changes, firmware changes, user operations, and other events, to facilitate traceability and analysis of system operations.

Physical connection specifications

Input connection: There are various types of input connections, and the phase current input is connected through specific terminals in different configurations, such as X120-7,8 connected to IL1, etc; The residual current input and phase voltage input also have corresponding terminals. The auxiliary power supply voltage input is connected to X100/1-2, and there are clear regulations for different DC or AC voltage ranges. Binary input is used for various functions, such as generating blocking signals, etc. The binary input terminals under different configurations are distributed on slots such as X110, X120, X130, etc.

Output connections: Output connections are divided into trip and control outputs, signal outputs, and IRF (internal fault relay) outputs. The tripping and control output are achieved through PO1-PO4 contacts, which can control most circuit breakers; The signal output is transmitted through SO1-SO4 contacts to indicate the starting and tripping status of the equipment; IRF contacts have different closed states under normal and fault conditions, used for self-monitoring systems of equipment.