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.