Apostolov, Alexander
AREVA Automation
The recently released IEC 61850 international standard for communications in substations brings a new era in the development of substations. It affects not only the design of the substation protection, monitoring and control system, but also the design of the substation secondary circuits. It continues the trend started by UCA 2.0 with highspeed peer-to-peer communications using Generic Substation Event (GSE) messages and introduces distributed applications based on current and voltage values communicated between devices connected to the substation local area network.
The paper analyses different substation communications architectures:
• With substation bus only
• With substation and process bus
The different types of devices required for each of the architectures are described. The paper analyzes the main modules in a conventional microprocessor relay and compares it with the implementation of protection functions in IEC 61850 based systems with distributed analog values. Merging units that provide the interface between the current and voltage sensors and the intelligent electronic devices at the equipment, bay or substation level are described. The distribution of signal and data processing functions between the different devices for both architectures are analyzed.
Some specific substation applications based on GSE messages and Sampled Analog Values are described later in the paper.
Performance analysis for the different types of applications allows the selection of optimal solutions for IEC 61850-based substation protection and control systems.
